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LTM8062 32VIN, 2A Module Power Tracking Battery Charger FEATURES
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DESCRIPTION
The LTM(R)8062 is a complete 32VIN, 2A Module(R) power tracking battery charger. The LTM8062 provides a constant-current/constant-voltage charge characteristic, a 2A maximum charge current, and employs a 3.3V float voltage feedback reference, so any desired battery float voltage up to 14.4V can be programmed with a resistor divider. The LTM8062 employs an input voltage regulation loop, which reduces charge current if the input voltage falls below a programmed level, set with a resistor divider. When the LTM8062 is powered by a solar panel, this input regulation loop is used to maintain the panel at peak output power. The LTM8062 also features preconditioning trickle charge, bad battery detection, a choice of termination schemes and automatic restart. The LTM8062 is packaged in a thermally enhanced, compact (9mm x 15mm x 4.32mm) over-molded land grid array (LGA) package suitable for automated assembly by standard surface mount equipment. The LTM8062 is RoHS compliant.
L, LT, LTC, LTM, Linear Technology, the Linear logo and Module are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners.
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Complete Battery Charger System Input Supply Voltage Regulation Loop for Peak Power Tracking in MPPT (Maximum Peak Power Tracking) Solar Applications Wide Input Voltage Range: 4.95V to 32V (40V Abs Max) 2A Charge Current Resistor Programmable Float Voltage Up to 14.4V Accommodates Li-Ion/Polymer, LiFePO4, SLA Integrated Input Reverse Voltage Protection User Selectable Termination: C/10 or Termination Timer 0.75% Float Voltage Reference Accuracy 9mm x 15mm x 4.32mm LGA Package
APPLICATIONS
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Industrial Handheld Instruments 12V to 24V Automotive and Heavy Equipment Desktop Cradle Chargers Solar Power Battery Charging
TYPICAL APPLICATION
2A LiFePO4 Module Battery Charger
2500 VIN 6V TO 32V VINA VIN VINREG RUN 4.7F TMR NTC GND
8062 TA01a
Charge Current vs Battery Voltage
LTM8062
BAT BIAS CHRG FAULT ADJ 2.87M 274k CHARGING CURRENT (mA) 2000
NORMAL CHARGING
1-CELL LiFePO4 (3.6V)
1500
1000
500
PRECONDITION TERMINATION
0 0 1 3 2 BATTERY VOLTAGE (V) 4
8062 TA01b
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LTM8062 ABSOLUTE MAXIMUM RATINGS
(Note 1)
PIN CONFIGURATION
TOP VIEW 7 BAT 6 5 VINA 4 BANK 1 3 GND 2 VIN 1 A B C D E F G H J K L BANK 4 BANK 3 BANK 2 BIAS ADJ FAULT CHRG GND NTC TMR RUN VINREG
VINA, VIN ...................................................................40V VINREG, RUN, CHRG, FAULT ......................VIN + 0.5, 40V TMR, NTC ................................................................2.5V BAT ...........................................................................15V BIAS ..........................................................................10V ADJ .............................................................................5V Maximum Internal Operating Temperature (Note 2)................................................................. 125C Maximum Body Solder Temperature..................... 245C
LGA PACKAGE 77-LEAD (15mm 9mm 4.32mm) TJMAX = 125C, JA = 17.0C/W, JCbottom = 6.1C/W, JCtop = 16.2C/W, JB = 11.2C/W, WEIGHT = 1.7g VALUES DETERMINED PER JEDEC 51-9, 51-12
ORDER INFORMATION
LEAD FREE FINISH LTM8062EV#PBF LTM8062IV#PBF TRAY LTM8062EV#PBF LTM8062IV#PBF PART MARKING* LTM8062V LTM8062V PACKAGE DESCRIPTION 77-Lead (15mm x 9mm x 4.32mm) LGA 77-Lead (15mm x 9mm x 4.32mm) LGA TEMPERATURE RANGE -40C to 125C -40C to 125C
Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container. For more information on lead free part marking, go to: http://www.linear.com/leadfree/ This product is only offered in trays. For more information go to: http://www.linear.com/packaging/
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LTM8062 ELECTRICAL CHARACTERISTICS
PARAMETER VIN Maximum Operating Voltage VIN Start Voltage VIN OVLO Threshold VIN OVLO Hysteresis VIN UVLO Threshold VIN UVLO Hysteresis VINA to VIN Diode Forward Voltage Drop Maximum BAT Float Voltage Input Supply Current Maximum BAT Charging Current ADJ Float Reference Voltage ADJ Recharge Threshold Voltage ADJ Precondition Threshold Voltage ADJ Precondition Threshold Hysteresis Voltage ADJ Input Bias Current VINREG Reference Voltage VINREG Bias Current NTC Range Limit (High) Voltage NTC Range Limit (Low) Voltage NTC Disable Impedance NTC Bias Current NTC Threshold Hysteresis RUN Threshold Voltage RUN Hysteresis Voltage RUN Input Bias Current CHRG, FAULT Output Low Voltage TMR Charge/Discharge Current TMR Disable Threshold Voltage Operating Frequency Note 1: Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. Exposure to any Absolute Maximum Rating condition for extended periods may affect device reliability and lifetime. Note 2: The LTM8062E is guaranteed to meet performance specifications from 0C to 125C internal. Specifications over the full -40C to 125C internal operating temperature range are assured by design, characterization and correlation with statistical process controls. The LTM8062I is guaranteed to meet specifications over the full -40C to 0.85 10mA Load 25 0.25 1 1.15 VNTC = 0.8V For Both High and Low Range Limits VRUN Rising 1.15 VINA Current = 2A IBAT = 2A Standby Mode RUN = 0, VIN Reg Open (Note 3) (Note 4)
l l
The l denotes the specifications which apply over the full internal operating temperature range, otherwise specifications are at TA = 25C. RUN = 2V.
CONDITIONS MIN 7.5 32 35 1 VIN Rising 4.6 0.3 0.55 14.7 85 18 1.8 3.275 3.25 3.3 82.5 2.3 95 65 110
l
TYP
MAX 32
UNITS V V V V V V V V A A
VIN Rising
40
2.1 3.325 3.34
A V V mV V mV nA nA
Threshold Relative to ADJ Float Reference (Note 3) ADJ Rising (Note 4) Relative to ADJ Precondition Threshold (Note 4) Charging Terminated CV Operation (Note 5) ADJ = 3V, IBAT = 1A VINREG = VINREG Reference VNTC Rising VNTC Falling 1.25 0.27 250 45 2.61
2.7 35 1.36 0.29 500
2.83 100 1.45 0.315 53
V nA V V k A % V mV nA
20 1.20 120 -10 0.4 1.25
V A V MHz
125C internal operating temperature range. Note that the maximum internal temperature is determined by specific operating conditions in conjunction with board layout, the rated package thermal resistance and other environmental factors. Note 3: The maximum BAT charging current is reduced by thermal foldback. See the Typical Performance Characteristics for details. Note 4: ADJ voltages measured through 250k equivalent series resistance. Note 5: Output battery float voltage programming resistor divider equivalent resistance = 250k compensates for input bias current.
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LTM8062 TYPICAL PERFORMANCE CHARACTERISTICS
Efficiency vs IBAT, 4.2V Float
84 82 80 EFFICIENCY (%) EFFICIENCY (%) 78 76 74 72 70 0 500 1000 IBAT (mA) 1500 2000
8062 G01
TA = 25C, unless otherwise noted.
Efficiency vs IBAT, 7.2V Float
87 86 85 VINA = 12V 88 87
Efficiency vs IBAT, 8.4V Float
VINA = 12V VINA = 24V
VINA = 24V 86 EFFICIENCY (%) VINA = 24V 85 VINA = 12V 84 83 82 81 0 500 1000 IBAT (mA) 1500 2000
8062 G02
84 83 82 81 80
0
500
1500 1000 IBAT (mA)
2000
2500
8062 G03
Efficiency vs IBAT, 14.4V Float
90 89 VINA = 24V ADJ FLOAT VOLTAGE (V) 88 EFFICIENCY (%) 87 86 85 84 83 82 0 500 1000 IBAT (mA) 1500 2000
8062 G04
ADJ Float Voltage vs Temperature
3.280 25
IBIAS vs IBAT, 4.2V Float
20 VINA = 12V 3.275 IBIAS (mA) 3.270 5 15
10 VINA = 24V
3.265 -50
0 -25 25 50 75 0 TEMPERATURE (C) 100 125 0 500 1000 IBAT (mA) 1500 2000
8062 G06
8062 G05
IBIAS vs IBAT, 7.2V Float
45 40 35 30 IBIAS (mA) IBIAS (mA) 25 20 15 10 5 0 0 500 1000 IBAT (mA) 1500 2000
8062 G07
IBIAS vs IBAT, 8.4V Float
50 45 40 45 40 35 VINA = 12V IBIAS (mA) 30 25 20 15 VINA = 24V 10 5 0 500 1000 IBAT (mA) 1500 2000
8062 G08
IBIAS vs IBAT, 14.4V Float
VINA = 12V
35 30 25 20 15 10 5 0
VINA = 24V
VINA = 24V
0 0 500 1000 IBAT (mA) 1500 2000
8062 G09
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LTM8062 TYPICAL PERFORMANCE CHARACTERISTICS
Input Current vs IBAT, 4.2V Float
900 800 700 INPUT CURRENT (mA) INPUT CURRENT (mA) 600 500 400 300 200 100 0 0 500 1000 IBAT (mA) 1500 2000
8062 G10
TA = 25C, unless otherwise noted.
Input Current vs IBAT, 7.2V Float
1400 1200 VINA = 12V 1000 800 600 400 VINA = 24V 200 0 0 500 1000 IBAT (mA) 1500 2000
8062 G11
Input Current vs IBAT, 8.4V Float
1600 1400 VINA = 12V INPUT CURRENT (mA) 1200 1000 800 600 VINA = 24V 400 200 0 0 500 1500 1000 IBAT (mA) 2000 2500
8062 G12
VINA = 12V
VINA = 24V
Input Current vs IBAT, 14.4V Float
1400 1200 200 INPUT CURRENT (mA) 250
IQ vs VINA, RUN = 0V, VINREG Open
2500
Maximum IBAT vs ADJ
2000 MAXIMUM IBAT (mA)
1000 IQ (A) 800 VINA = 24V 600 400 50 200 0 0 500 1000 IBAT (mA) 1500 2000
8062 G13
150
1500
100
1000
500
0 0 10 20 VINA (V) 30 40
8062 G14
0 0 0.5 1 1.5 2 2.5 ADJ VOLTAGE (V) 3 3.5
8062 G15
Maximum IBAT vs VINREG
2500 2000
Maximum Charge Current vs Temperature
25
Temperature Rise vs IBAT, 4.2V Float Voltage
1500
1200
TEMPERATURE RISE (C)
2000 CHARGE CURRENT (mA) MAXIMUM IBAT (mA)
1600
20
15 VINA = 24V 10 VINA = 12V 5
1000
800
500
400
0 2 2.5 VINREG (V)
8062 G16
3
3.5
0 -40 -20
0 0 20 40 60 80 100 120 TEMPERATURE (C)
8062 G17
0
500
1000 IBAT (mA)
1500
2000
8062 G18
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LTM8062 TYPICAL PERFORMANCE CHARACTERISTICS
Temperature Rise vs IBAT, 7.2V Float Voltage
30 25 TEMPERATURE RISE (C) TEMPERATURE RISE (C) 20 VINA = 24V 15 VINA = 12V 10 5 0 0 500 1000 IBAT (mA) 1500 2000
8062 G19
TA = 25C, unless otherwise noted.
Temperature Rise vs IBAT, 8.4V Float Voltage
30 25 20 15 VINA = 24V 10 5 0 0 500 1000 IBAT (mA) 1500 2000
8062 G20
VINA = 12V
Temperature Rise vs IBAT, 14.4V Float Voltage
40 VIN STANDBY MODE CURRENT (mA) 35 TEMPERATURE RISE (C) 30 25 VINA = 24V 20 15 10 5 0 0 500 1000 IBAT (mA) 1500 2000
8062 G21
VIN Standby Mode Current vs Temperature
6 5 4 VINA = 12V 3 VINA = 24V 2 1 0 -50
0 50 TEMPERATURE (C)
100
8062 G22
PIN FUNCTIONS
GND (Bank 1, Pin L7): Power and Signal Ground Return. BAT (Bank 2): Battery Charge Current Output Bus. The charge function operates to achieve the final float voltage at this pin. The auto-restart feature initiates a new charging cycle when the voltage at the ADJ pin falls 2.5% below the float voltage. Once the charge cycle is terminated, the input bias current of the BAT pin is reduced to minimize battery discharge while the charger remains connected. VINA (Bank 3): Anode of input reverse protection Schottky diode. Connect the input power here if input reverse voltage protection is desired. VIN (Bank 4): Charger Input Supply. Decouple with at least 4.7F to GND. Connect the input power here if no input reverse voltage protection is needed. BIAS (Pin G7): The BIAS pin connects to the internal power bus. In most cases connect to VBAT. If this is not desirable, connect to a power source greater than 2.8V and less than 10V. CHRG (Pin K7): Open-Collector Charger Status Output; typically pulled up through a resistor to a reference voltage. This status pin can be pulled up to voltages as high as VIN and can sink currents up to 10mA. During a battery charging cycle, CHRG is pulled low. When the charge current falls below C/10,
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LTM8062 PIN FUNCTIONS
the CHRG pin becomes high impedance. If the internal timer is used for termination, the pin stays low during the charging cycle until the charge current drops below a C/10 rate, approximately 200mA, even though the charger will continue to top off the battery until the end-of-charge timer terminates the charge cycle. A temperature fault also causes this pin to be pulled low (see the Applications Information section). NTC (Pin H6): Battery Temperature Monitor Pin. This pin is the input to the NTC (negative temperature coefficient) thermistor temperature monitoring circuit. This function is enabled by connecting a 10k, B = 3380 NTC thermistor from the NTC pin to ground. The pin sources 50A, and monitors the voltage across the 10k thermistor. When the voltage on this pin is above 1.36V (T < 0C) or below 0.29V (T > 40C), charging is disabled and the CHRG and FAULT pins are both pulled low. If the internal timer termination is being used, the timer is paused, suspending the charging cycle. Charging resumes when the voltage on NTC returns to within the 0.29V to 1.36V active region. There is approximately 5C of temperature hysteresis associated with each of the temperature thresholds. The temperature monitoring function remains enabled while thermistor resistance to ground is less than 250k. If this function is not desired, leave the NTC pin unconnected. ADJ (Pin H7): Battery Float Voltage Feedback Input. The charge function operates to achieve a final float voltage of 3.3V on this pin. The output battery float voltage (VBAT(FLT)) is programmed using a resistor divider. VBAT(FLT) can be programmed up to 14.4V. The auto-restart feature initiates a new charging cycle when the voltage at the ADJ pin falls 2.5% below the float voltage reference. The ADJ pin input bias current is 110nA. Using a resistor divider with an equivalent input resistance at the ADJ pin of 250k compensates for input bias current error. Required resistor values to program desired VBAT(FLT) follow the equations: R1= R2 = VBAT(FLT) * 2.5 * 10 3.3 R1* 2.5 * 105 R1- (2.5 * 105 ) ()
5
pin can be pulled up to voltages as high as VIN and can sink currents up to 10mA. This pin indicates charge cycle fault conditions during a battery charging cycle. A temperature fault causes this pin to be pulled low. If the internal timer is used for termination, a bad battery fault also causes this pin to be pulled low. If no fault conditions exist, the FAULT pin remains high impedance (see the Applications Information section). TMR (Pin J6): End-Of-Cycle Timer Programming Pin. If a timerbased charge termination is desired, connect a capacitor from this pin to ground. Full charge end-of cycle time (in hours) is programmed with this capacitor following the equation: tEOC = CTIMER * 4.4 * 106 A bad battery fault is generated if the battery does not reach the precondition threshold voltage within one-eighth of tEOC, or: tPRE = CTIMER * 5.5 * 105 A 0.68F capacitor is often used, which generates a timer EOC at three hours, and a precondition limit time of 22.5 minutes. If a timer-based termination is not desired, the timer function can be disabled by connecting the TMR pin to ground. With the timer function disabled, charging terminates when the charge current drops below a C/10 rate, approximately 200mA. VINREG (Pin L6): Input Voltage Regulation Reference. The maximum charge current is reduced when this pin is below 2.7V. Connecting a resistor divider from VIN to this sets the minimum operational VIN voltage. This is typically used to program the peak power voltage for a solar panel. The LTM8062 servos the maximum charge current required to maintain the programmed operational VIN voltage, through maintaining the voltage on VINREG at or above 2.7V. If the voltage regulation feature is not used, connect the pin to VIN. RUN (Pin K6): Precision Threshold Enable Input Pin. The RUN threshold is 1.25V (rising), with 120mV of input hysteresis. When in shutdown mode, all charging functions are disabled. The precision threshold allows use of the RUN pin to incorporate UVLO functions. If the RUN pin is pulled below 0.4V, the IC enters a low current shutdown mode where the VIN pin current is reduced to 15A. Typical RUN pin input bias current is 10nA. If the shutdown function is not desired, connect the pin to the VIN pin.
()
R1 is connected from BAT to ADJ, and R2 is connected from ADJ to ground. FAULT (Pin J7): Open-Collector Fault Status Output; typically pulled up through a resistor to a reference voltage. This status
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LTM8062 BLOCK DIAGRAM
VINA VIN 8.2H SENSE RESISTOR BAT
0.1F
0.1F
10F
BIAS
VINREG INTERNAL COMPENSATION CURRENT MODE BATTERY MANAGEMENT CONTROLLER
RUN ADJ TMR NTC
ADJ
GND
FAULT
CHRG
8062 BD
OPERATION
The LTM8062 is a complete monolithic, mid-power, power tracking battery charger, addressing high input voltage applications with solutions that use a minimum of external components. The product can be programmed for float voltages between 3.3V and 14.4V with just two external resistors, operating under a 1MHz fixed frequency, average current mode step-down architecture. A 2A power Schottky diode is integrated within the Module for reverse input voltage protection. A wide input range allows the operation to full charge from an input voltage up to 32V. A precision threshold on the RUN pin allows the implementation of a UVLO feature by using a simple resistor network. The charger can also be put into a low current shutdown mode, in which the input supply bias is reduced to only 15A. The LTM8062 employs an input voltage regulation loop, which reduces charge current if a monitored input voltage falls below a programmed level. When the LTM8062 is powered by a solar panel, the input regulation loop is used to maintain the panel at peak output power. The LTM8062 automatically enters a battery precondition mode if the sensed battery voltage is very low. In this mode, the charge current is reduced to 300mA. Once the battery voltage climbs above the internally set precondition threshold (2.3V at the ADJ pin), the Module automatically increases the maximum charge current to the full programmed value. The LTM8062 can use a charge current based C/10 termination scheme, which ends a charge cycle when the battery charge current falls to one-tenth the programmed charge current. The LTM8062 also contains an internal charge cycle control timer, for timer-based termination. When using the internal timer, the charge cycle can continue beyond the C/10 level to top-off the battery. The charge cycle terminates when the programmed time elapses, about three hours for a 0.68F timer capacitor. The CHRG status pin continues to signal charging at a C/10 or greater rate, regardless of
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LTM8062 OPERATION
which termination scheme is used. When the timer-based scheme is used, the LTM8062 also supports bad battery detection, which triggers a system fault if a battery stays in precondition mode for more than one-eighth of the total programmed charge cycle time. Once charging terminates and the LTM8062 is not actively charging, the charger automatically enters a low current standby mode in which supply bias currents are reduced to 85A. If the battery voltage drops 2.5% from the full charge float voltage, the LTM8062 engages an automatic charge cycle restart. The IC also automatically restarts a new charge cycle after a bad-battery fault once the failed battery is removed and replaced with another battery. The LTM8062 contains a battery temperature monitoring circuit. This feature, using a thermistor, monitors battery temperature and will not allow charging to begin, or will suspend charging, and signal a fault condition if the battery temperature is outside a safe charging range. The LTM8062 contains two digital open-collector outputs, CHRG and FAULT, which provide charger status and signal fault conditions. These binary coded pins signal battery charging, standby or shutdown modes, battery temperature faults and bad battery faults. For reference, C/10 and TMR based charging cycles are shown in Figures 1 and 2.
FLOAT VOLTAGE RECHARGE THRESHOLD BATTERY VOLTAGE PRECONDITION THRESHOLD MAXIMUM CHARGE CURRENT BATTERY CHARGE CURRENT
PRECONDITION CURRENT C/10 0 AMPS 1
CHRG FAULT 0 1 0 1 RUN 0
8062 F01
Figure 1. Typical C/10 Terminated Charge Cycle (TMR Grounded, Time Not to Scale)
FLOAT VOLTAGE RECHARGE THRESHOLD BATTERY VOLTAGE PRECONDITION THRESHOLD MAXIMUM CHARGE CURRENT BATTERY CHARGE CURRENT
PRECONDITION CURRENT C/10 CURRENT 1
CHRG FAULT 0 1 0 1 0 < tEOC /8 tEOC AUTOMATIC RESTART
RUN
8062 F02
Figure 2. Typical EOC (Timer-Based) Terminated Charge Cycle (Capacitor Connected to TMR, Time Not to Scale)
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LTM8062 APPLICATIONS INFORMATION
For most applications, the design process is straight forward, summarized as follows: 1. Look at Table 1 and find the row that has the desired input voltage range and battery float voltage. 2. Apply the recommended CIN and RADJ values. 3. Connect BIAS as indicated. While these component combinations have been tested for proper operation, it is incumbent upon the user to verify proper operation over the intended system's line, load and environmental conditions. Bear in mind that the maximum output current is limited by junction temperature, the relationship between the input and output voltage magnitude and polarity and other factors. Please refer to the graphs in the Typical Performance Characteristics section for guidance.
Table 1. Recommended Component Values and Configuration (TA = 25C)
VIN RANGE (V)* 6 to 32 6 to 32 6 to 32 6.25 to 32 9.5 to 32 9.75 to 32 11 to 32 11.5 to 32 12.75 to 32 16.5 to 32 17 to 32 18.25 to 32 19 to 32 19.5 to 32 VBAT (V) 3.6 4.1 4.2 4.7 7.05 7.2 8.2 8.4 9.4 12.3 12.6 13.5 14.08 14.42 CIN 4.7F 1206 X7R 50V 4.7F 1206 X7R 50V 4.7F 1206 X7R 50V 4.7F 1206 X7R 50V 4.7F 1206 X7R 50V 4.7F 1206 X7R 50V 4.7F 1206 X7R 50V 4.7F 1206 X7R 50V 4.7F 1206 X7R 50V 4.7F 1206 X7R 50V 4.7F 1206 X7R 50V 4.7F 1206 X7R 50V 4.7F 1206 X7R 50V 4.7F 1206 X7R 50V RADJ1 TOP (k) 274 312 320 357 530 549 626 642 715 942 965 1020 1090 1110 RADJ2 BOTTOM (k) 2870 1260 1150 835 464 459 417 412 383 344 340 328 332 328
Reverse Protection Diode The LTM8062 integrates a high voltage power Schottky diode to provide input reverse voltage protection. The anode of this diode is connected to VINA, and the cathode is connected to VIN. There is a small mount of capacitance at each end; please see the Block Diagram. Input Supply Voltage Regulation The LTM8062 contains a voltage monitor pin that enables programming a minimum operational voltage. Connecting a resistor divider from VIN to the VINREG pin enables programming of minimum input supply voltage, typically used to program the peak power voltage for a solar panel. Maximum charge current is reduced when the VINREG pin is below the regulation threshold of 2.7V. If the VINREG function is not used, and if the input supply cannot provide enough power to satisfy the requirements of an LTM8062 charger, the input supply voltage will collapse. A minimum operating supply voltage can thus be programmed by monitoring the supply through a resistor divider, such that the desired minimum voltage corresponds to 2.7V at the VINREG pin. The LTM8062 servos the maximum output charge current to maintain the voltage on VINREG at or above 2.7V. Programming of the desired minimum voltage is accomplished by connecting a resistor divider as shown in Figure 3. The ratio of RIN1/RIN2 for a desired minimum voltage (VIN(MIN)) is: RIN1/RIN2 = (VIN(MIN) /2.7) - 1 If the voltage regulation feature is not used, connect the VINREG pin to VIN.
INPUT SUPPLY RIN1 VINREG RIN2
8062 F03
VIN
LTM8062
* Input bulk capacitance is required.
VIN Input Supply The LTM8062 is biased directly from the charger input supply through the VIN pin. This pin provides large switched currents, so a high quality low ESR decoupling capacitor is recommended to minimize voltage glitches on VIN. 4.7F is typically adequate for most charger applications.
Figure 3. Resistive Divider Sets Minimum VIN
BIAS Pin Considerations The BIAS pin is used to provide drive power for the internal power switching stage and operate other internal
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LTM8062 APPLICATIONS INFORMATION
circuitry. For proper operation, it must be powered by at least 2.8V and no more than the absolute maximum rating of 10V. In most applications, connect BIAS to BAT. If there is no BIAS supply available or the battery voltage is below 2.8V, the internal switch requires more headroom from VIN for proper operation. Please refer to the Typical Performance Characteristics curves for minimum start and running requirements under various battery conditions. When charging a 2-cell battery using a relatively high input voltage, the LTM8062 power dissipation can be reduced by connecting BIAS to a voltage between 2.8V and 3.3V. Output Capacitance In many applications, the internal BAT capacitance of the LTM8062 is sufficient for proper operation. There are cases, however, where it may be necessary to add capacitance or otherwise modify the output impedance of the LTM8062. Case 1: the Module is physically located far from the battery and the added line impedance may interfere with the control loop. Case 2: the battery ESR is very small or very large; the LTM8062 controller is designed for a wide range, but some battery packs have an ESR outside of this range. Case 3: there is no battery at all. As the charger is designed to work with the ESR of the battery, the output may oscillate if no battery is present. The optimum ESR is about 100m, but ESR values both higher and lower will work. Table 2 shows a sample of parts successfully tested by Linear Technology:
Table 2
PART NUMBER 16TQC22M 35SVPD18M TPSD226M025R0100 T495D226K025AS TPSC686M006R0150 TPSB476M006R0250 APXE100ARA680ME61G APS-150ELL680MHB5S DESCRIPTION 22F 16V, POSCAP , 18F 35V, OS-CON , 22F 25V Tantalum , 22F 25V, Tantalum , 68F 6V, Tantalum , 47F 6V, Tantalum , 68F 10V Aluminum , 68F 25V Aluminum , MANUFACTURER Sanyo Sanyo AVX Kemet AVX AVX Nippon Chemicon Nippon Chemicon
RIN2 RIN1 VIN V+ V- R RSET VIN VINREG LTM8062
8062 F04
MPPT Temperature Compensation A typical solar panel is comprised of a number of series-connected cells, each cell being a forward-biased p-n junction. As such, the open-circuit voltage (VOC) of a solar cell has a temperature coefficient that is similar to a common p-n diode, or about -2mV/C. The peak power point voltage (VMP) for a crystalline solar panel can be approximated as a fixed voltage below VOC, so the temperature coefficient for the peak power point is similar to that of VOC. Panel manufacturers typically specify the 25C values for VOC, VMP, and the temperature coefficient for VOC, making determination of the temperature coefficient for VMP of a typical panel straight forward. The LTM8062 employs a feedback network to program the VIN input regulation voltage. Manipulation of the network makes for efficient implementation of various temperature compensation schemes for a maximum peak power tracking (MPPT) application. As the temperature characteristic for a typical solar panel VMP voltage is highly linear, a simple solution for tracking that characteristic can be implemented using a Linear Technology LM234 3-terminal temperature sensor. This creates an easily programmable, linear temperature dependent characteristic. In the circuit shown in Figure 4, R IN1 = -RSET * (TC * 4405), and R IN2 = RIN1 VMP (25C) + RIN1 * (0.0674 / RSET ) VINREG - 1
where TC = temperature coefficient (in V/C), and VMP(25C) = maximum power voltage at 25C.
LINEAR TECHNOLOGY LM234
If system constraints preclude the use of electrolytic capacitors, a series R-C network may be used. Use a ceramic capacitor of at least 22F and an equivalent resistance of 100m. An example of this is shown in the Typical Applications section.
Figure 4. MPPT Temperature Compensation Network
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LTM8062 APPLICATIONS INFORMATION
For example, given a common 36-cell solar panel that has the following specified characteristics: Open Circuit Voltage (VOC) = 21.7V Maximum Power Voltage (VMP) = 17.6V Open-Circuit Voltage Temperature Coefficient (VOC) = -78mV/C As the temperature coefficient for VMP is similar to that of VOC, the specified temperature coefficient for VOC (TC) of -78mV/C and the specified peak power voltage (VMP(25C)) of 17.6V can be inserted into the equations to calculate the appropriate resistor values for the temperature compensation network in Figure 4. With RSET equal to 1k, then: RSET = 1k R IN1 = -1k * (-0.078 * 4405) = 344k 344k = 24.4k 17.6 + 344k * (0.0674 / 1k) -1 2.7 Battery Voltage Temperature Compensation R IN2 = Some battery chemistries have charge voltage requirements that vary with temperature. Lead-acid batteries in particular experience a significant change in charge voltage requirements as temperature changes. For example, manufacturers of large lead-acid batteries recommend a float charge of 2.25V/cell at 25C. This battery float voltage, however, has a temperature coefficient which is typically specified at -3.3mV/C per cell. In a manner similar to the MPPT temperature correction outlined previously, implementation of linear battery charge voltage temperature compensation can be accomplished by incorporating a Linear Technology LM234 into the output feedback network. For example, a 6-cell lead acid battery has a float charge voltage that is commonly specified at 2.25V/cell at 25C, or 13.5V, and a -3.3mV/C per cell temperature coefficient, or -19.8mV/C. Using the feedback network shown in Figure 5, with the desired temperature coefficient (TC) and 25C float voltage (VFLOAT (25C)) specified, and using a convenient value of 2.4k for RSET, necessary resistor values follow the relations: RFB1 = -RSET * (TC * 4405) = -2.4k * (-0.0198 * 4405) = 210k RFB2 = RFB1 VFLOAT (25C) + RFB1 * (0.0674 / RSET ) -1 VFB
210k 13.5 + 210k * (0.0674 / 2.4k) -1 3.3 = 43k = RFB3 = 250k - RFB1||RFB2 = 250k - 210k||43k = 215k (see the Battery Float Voltage Programming section) While the circuit in Figure 5 creates a linear temperature characteristic that follows a typical -3.3mV/C per cell lead-acid specification, the theoretical float charge
14.3 14.2
BAT VFLOAT (V) RFB1 210k RFB3 215k ADJ RFB2 43k
8062 F05a
14.0 V+ LINEAR TECHNOLOGY V- LM234
+
6-CELL LEAD-ACID BATTERY
13.8 13.6 13.4 13.2 13.0 12.8 12.6 -10 0
-19.8mV/C
LTM8062
RSET 2.4k
R
20 30 10 40 TEMPERATURE (C)
50
60
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Figure 5. Lead-Acid 6-Cell Float Charge Voltage vs Temperature with a -19.8mV/C Temperature Coefficient Using LM234 with the Feedback Network
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12
LTM8062 APPLICATIONS INFORMATION
14.8 14.6 14.4 BAT VFLOAT (V) 196k LTM8062 198k ADJ 69k
8062 F06a
14.2 6-CELL LEAD-ACID BATTERY 22k B = 3380
+
14.0 13.8 13.6 13.4 13.2 13.0 12.8 -10 0 20 30 10 40 TEMPERATURE (C) 50 60 PROGRAMMED VBAT(FLOAT) THEORETICAL VFLOAT
69k
8062 F06b
Figure 6. Thermistor-Based Temperature Compensation Network Programs VFLOAT to Closely Match Ideal Lead-Acid Float Charge Voltage for 6-Cell Charger
voltage characteristic is slightly nonlinear. This nonlinear characteristic follows the relation: VFLOAT = 4 * 10-5 (T2) - 6 * 10-3(T) + 2.375 (with a 2.18V minimum) where T = temperature in C. A thermistor-based network can be used to approximate the nonlinear ideal temperature characteristic across a reasonable operating range, as shown in Figure 6. Status Pins The LTM8062 reports charger status through two opencollector outputs, the CHRG and FAULT pins. These pins can be pulled up as high as VIN, and can sink up to 10mA. The CHRG pin indicates that the charger is delivering current at greater than a C/10 rate, or one-tenth of the programmed charge current. The FAULT pin signals badbattery and NTC faults. These pins are binary coded, as shown in Table 3.
Table 3. Status Pin State
CHRG High High Low Low FAULT High Low High Low STATUS Not Charging--Standby or Shutdown Mode Bad-Battery Fault (Precondition Timeout/EOC Failure) Normal Charging at C/10 or Greater NTC Fault (Pause)
results in pulsing at the CHRG output. An LED connected to this pin will exhibit a blinking pattern, indicating to the user that a battery is not present. The frequency of this blinking pattern is dependent on the output capacitance. C/10 Charge Termination The LTM8062 supports a low current based termination scheme, where a battery charge cycle terminates when the charge current falls below one-tenth the programmed charge current, or approximately 200mA. This termination mode is engaged by shorting the TMR pin to ground. When C/10 termination is used, an LTM8062 charger sources battery charge current as long as the average current level remains above the C/10 threshold. As the full-charge float voltage is achieved, the charge current falls until the C/10 threshold is reached, at which time the charger terminates and the LTM8062 enters standby mode. The CHRG status pin follows the charger cycle and is high impedance when the charger is not actively charging. There is no provision for bad-battery detection if C/10 termination is used. Timer Charge Termination The LTM8062 supports a timer-based termination scheme, where a battery charge cycle terminates after a specific amount of time elapses. Timer termination is engaged when a capacitor (CTIMER) is connected from the TMR pin to ground. The timer cycle time span (tEOC) is determined by CTIMER in the equation: CTIMER = tEOC * 2.27 * 10-7 (Hours)
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If the battery is removed from an LTM8062 charger that is configured for C/10 termination, a low amplitude sawtooth waveform appears at the charger output, due to cycling between termination and recharge events. This cycling
13
LTM8062 APPLICATIONS INFORMATION
When charging at a 1C rate, tEOC is commonly set to three hours, which requires a 0.68F capacitor. The CHRG status pin continues to signal charging, regardless of which termination scheme is used. When timer termination is used, the CHRG status pin is pulled low during a charge cycle until the charge current falls below the C/10 threshold. The charger continues to top off the battery until timer EOC, when the LTM8062 terminates the charge cycle and enters standby mode. Termination at the end of the timer cycle only occurs if the charge cycle was successful. A successful charge cycle occurs when the battery is charged to within 2.5% of the full-charge float voltage. If a charge cycle is not successful at EOC, the timer cycle resets and charging continues for another full timer cycle. When VBAT drops 2.5% from the full-charge float voltage, whether by battery loading or replacement of the battery, the charger automatically resets and starts charging. Preconditioning and Bad-Battery Fault The LTM8062 has a precondition mode, where the charge current is limited to 15% of the maximum charge current, or approximately 300mA. Precondition mode is engaged if the voltage on the BAT pin is below the precondition threshold, or approximately 70% of the float voltage. Once the BAT voltage rises above the precondition threshold, normal fullcurrent charging can commence. The LTM8062 incorporates 90mV hysteresis to avoid spurious mode transitions. Bad-battery detection is engaged when the internal timer is used for termination (capacitor tied to TMR). This fault detection feature is designed to identify failed cells. A bad-battery fault is triggered when the voltage on BAT remains below the precondition threshold for greater than one-eighth of a full timer cycle (one-eighth EOC). A badbattery fault is also triggered if a normally charging battery re-enters precondition mode after one-eighth EOC. When a bad-battery fault is triggered, the charge cycle is suspended, and the CHRG status pin becomes high impedance. The FAULT pin is pulled low to signal that a fault has been detected. Cycling the charger's power or shutdown function initiates a new charge cycle, but the LTM8062 charger does not require a manual reset. Once a bad-battery fault is detected, a new timer charge cycle initiates if the BAT pin exceeds the precondition threshold voltage. During a bad-battery fault, a small current is sourced from the charger; removing the failed battery allows the charger output voltage to rise above the preconditioning threshold voltage and initiate a charge cycle reset. A new charge cycle is started by connecting another battery to the charger output. Battery Temperature Fault: NTC The LTM8062 can accommodate battery temperature monitoring by using an NTC (negative temperature coefficient) thermistor close to the battery pack. The temperature monitoring function is enabled by connecting a 10k, 3380 NTC thermistor from the NTC pin to ground. If the NTC function is not desired, leave the pin open. The NTC pin sources 50A, and monitors the voltage dropped across the 10k thermistor. When the voltage on this pin is above 1.36V (0C) or below 0.29V (40C), the battery temperature is out of range, and the LTM8062 triggers an NTC fault. The NTC fault condition remains until the voltage on the NTC pin corresponds to a temperature within the 0C to 40C range. Both hot and cold thresholds incorporate 20% hysteresis, which equates to about 5C. If higher operational charging temperatures are desired, the temperature range can be expanded by adding series resistance to the 10k NTC resistor. Adding a 909 resistor will increase the effective temperature threshold to 45C, for example. During an NTC fault, charging is halted and both status pins are pulled low. If timer termination is enabled, the timer count is suspended and held until the fault condition is cleared. Thermal Foldback The LTM8062 contains a thermal foldback protection feature that reduces charge current as the IC junction temperature approaches 125C. In most cases, on-chip temperatures servo such that any overtemperature conditions are relieved with only slight reductions in maximum charge current. In some cases, the thermal foldback protection feature can reduce charge currents below the C/10 threshold. In applications that use C/10 termination (TMR = 0V), the LTM8062 will suspend charging and enter standby mode until the overtemperature condition is relieved.
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14
LTM8062 APPLICATIONS INFORMATION
ADJ BAT NTC FAULT TMR CHRG GND
(OPTIONAL) RUN VINREG CBAT
VINA
GND
CIN VIN
THERMAL VIAS
8062 F07
Figure 7. Suggested Layout and Via Placement
PCB Layout Most of the headaches associated with PCB layout have been alleviated or even eliminated by the high level of LTM8062 integration. The LTM8062 is nevertheless a switching power supply, and care must be taken to minimize EMI and ensure proper operation. Even with the high level of integration, you may fail to achieve specified operation with a haphazard or poor layout. See Figure 7 for a suggested layout. Ensure that the grounding and heat sinking are acceptable. 1. Place the CIN capacitor as close as possible to the VIN and GND connection of the LTM8062. 2. If used, place the CBAT capacitor as close as possible to the BAT and GND connection of the LTM8062. 3. Place the CIN and CBAT (if used) capacitors such that their ground current flows directly adjacent or underneath the LTM8062. 4. Connect all of the GND connections to as large a copper pour or plane area as possible on the top layer. Avoid breaking the ground connection between the external components and the LTM8062. 5. For good heat sinking, use vias to connect the GND copper area to the board's internal ground planes. Liberally distribute these GND vias to provide both a good ground connection and thermal path to the internal planes of the
printed circuit board. Pay attention to the location and density of the thermal vias in Figure 5. The LTM8062 can benefit from the heat-sinking afforded by vias that connect to internal GND planes at these locations, due to their proximity to internal power handling components. The optimum number of thermal vias depends upon the printed circuit board design. For example, a board might use very small via holes. It should employ more thermal vias than a board that uses larger holes. Hot-Plugging Safely The small size, robustness and low impedance of ceramic capacitors make them an attractive option for the input bypass capacitor of LTM8062. However, these capacitors can cause problems if the LTM8062 is plugged into a live input supply (see Application Note 88 for a complete discussion). The low loss ceramic capacitor combined with stray inductance in series with the power source forms an underdamped tank circuit, and the voltage at the VIN pin of the LTM8062 can ring to more than twice the nominal input voltage, possibly exceeding the LTM8062's rating and damage the part. If the input supply is poorly controlled or the user will be plugging the LTM8062 into an energized supply, the input network should be designed to prevent this overshoot. This can be accomplished by installing a small resistor in series with VIN, but the most popular method of controlling input voltage overshoot is
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15
LTM8062 APPLICATIONS INFORMATION
to add an electrolytic bulk capacitor to the VIN net. This capacitor's relatively high equivalent series resistance damps the circuit and eliminates the voltage overshoot. The extra capacitor improves low frequency ripple filtering and can slightly improve the efficiency of the circuit, though it is physically large. Thermal Considerations The thermal performance of the LTM8062 is given in the Typical Performance Characteristics section. These curves were generated by the LTM8062 mounted to a 58cm2 4-layer FR4 printed circuit board. Boards of other sizes and layer count can exhibit different thermal behavior, so it is incumbent upon the user to verify proper operation over the intended system's line, load and environmental operating conditions. For increased accuracy and fidelity to the actual application, many designers use FEA to predict thermal performance. To that end, the Pin Configuration section of the data sheet typically gives four thermal coefficients: 1. JA: Thermal resistance from junction to ambient. 2. JCbottom : Thermal resistance from junction to the bottom of the product case. 3. JCtop : Thermal resistance from junction to top of the product case. 4. JB: Thermal resistance from junction to the printed circuit board. While the meaning of each of these coefficients may seem to be intuitive, JEDEC has defined each to avoid confusion and inconsistency. These definitions are given in JESD 51-12, and are quoted or paraphrased below: 1. JA is the natural convection junction-to-ambient air thermal resistance measured in a one cubic foot sealed enclosure. This environment is sometimes referred to as "still air" although natural convection causes the air to move. This value is determined with the part mounted to a JESD 51-9 defined test board, which does not reflect an actual application or viable operating condition. 2. JCbottom is the junction-to-board thermal resistance with all of the component power dissipation flowing through the bottom of the package. In the typical Module, the bulk of the heat flows out the bottom of the package, but there is always heat flow out into the ambient environment. As a result, this thermal resistance value may be useful for comparing packages but the test conditions don't generally match the user's application. 3. JCtop is determined with nearly all of the component power dissipation flowing through the top of the package. As the electrical connections of the typical Module are on the bottom of the package, it is rare for an application to operate such that most of the heat flows from the junction to the top of the part. As in the case of JCbottom, this value may be useful for comparing packages but the test conditions don't generally match the user's application. 4. JB is the junction-to-board thermal resistance where almost all of the heat flows through the bottom of the Module and into the board, and is really the sum of the JCbottom and the thermal resistance of the bottom of the part through the solder joints and through a portion of the board. The board temperature is measured a specified distance from the package, using a two sided, two layer board. This board is described in JESD 51-9. The most appropriate way to use the coefficients is when running a detailed thermal analysis, such as FEA, which considers all of the thermal resistances simultaneously. None of them can be individually used to accurately predict the thermal performance of the product, so it would be inappropriate to attempt to use any one coefficient to correlate to the junction temperature versus load graphs given in the LTM8033 data sheet. A graphical representation of these thermal resistances is given in Figure 8. The blue resistances are contained within the Module, and the green are outside. The die temperature of the LTM8062 must be lower than the maximum rating of 125C, so care should be taken in the layout of the circuit to ensure good heat sinking of the LTM8062. The bulk of the heat flow out of the LTM8062 is through the bottom of the module and the LGA pads into the printed circuit board. Consequently a poor printed circuit board design can cause excessive heating, resulting in impaired performance or reliability. Please refer to the PCB Layout section for printed circuit board design suggestions.
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16
LTM8062 APPLICATIONS INFORMATION
JUNCTION-TO-AMBIENT RESISTANCE (JESD 51-9 DEFINED BOARD) JUNCTION-TO-CASE (TOP) RESISTANCE CASE (TOP)-TO-AMBIENT RESISTANCE
JUNCTION
JUNCTION-TO-BOARD RESISTANCE JUNCTION-TO-CASE CASE (BOTTOM)-TO-BOARD (BOTTOM) RESISTANCE RESISTANCE BOARD-TO-AMBIENT RESISTANCE
AMBIENT
80421 F08
MODULE DEVICE
Figure 8. Thermal Resistances Among Module Device Printed Circuit Board and Ambient Environment
TYPICAL APPLICATIONS
Basic 2A, 2-Cell LiFePO4 Battery Charger with C/10 Termination
VIN 9.5V TO 32VDC LTM8062
VINA VIN VINREG RUN 4.7F TMR NTC
BAT BIAS CHRG FAULT ADJ 459k 549k 2-CELL LiFePO4 (2x 3.6V) BATTERY
+
(OPTIONAL ELECTROLYTIC CAPACITOR)
GND
8062 TA02
2A Solar Panel Power Manager with 8.4V Lithium Ion Battery Pack and 16V Peak Power Tracking
VIN SOLAR POWER UNIT LTM8062
VINA VIN 499k 4.7F 100k VINREG RUN TMR NTC
BAT BIAS CHRG FAULT ADJ 412k 642k 2-CELL Li-ION (2x 4.2V) BATTERY
+
(OPTIONAL ELECTROLYTIC CAPACITOR)
NTC 10k B = 3380
GND
8062 TA03
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17
LGA Package 77-Lead (15mm x 9mm x 4.32mm)
(Reference LTC DWG # 05-08-1856 Rev A)
DETAIL A X Y A B C D E 15 BSC MOLD CAP SUBSTRATE G 0.27 - 0.37 3.95 - 4.05 Z 1.27 BSC H J K L aaa Z PADS SEE NOTES 3 DETAIL B 2.540 3.810 0.635 0.025 SQ. 76x eee S X Y 7.62 BSC 12.70 BSC F 4.22 - 4.42 7 6 5 4 3 1 2 PAD 1 DIA (0.635)
LTM8062
PACKAGE DESCRIPTION
// bbb Z DETAIL B
4.1275 3.4925
3.810
2.540
1.270
0.000
6.350
5.080
3.810 DETAIL A
2.540
1.270
1.270
0.9525 1.5875
18
PACKAGE BOTTOM VIEW
aaa Z
9 BSC
PAD 1 CORNER
4
PACKAGE TOP VIEW
NOTES: 1. DIMENSIONING AND TOLERANCING PER ASME Y14.5M-1994 2. ALL DIMENSIONS ARE IN MILLIMETERS 3 4 LAND DESIGNATION PER JESD MO-222, SPP-010
COMPONENT PIN "A1"
0.000
0.9525 1.5875
1.270
LTMXXXXXX Module
2.540
3.810
DETAILS OF PAD #1 IDENTIFIER ARE OPTIONAL, BUT MUST BE LOCATED WITHIN THE ZONE INDICATED. THE PAD #1 IDENTIFIER MAY BE EITHER A MOLD OR MARKED FEATURE
5.080
5. PRIMARY DATUM -Z- IS SEATING PLANE 6. THE TOTAL NUMBER OF PADS: 77 SYMBOL TOLERANCE aaa 0.15 bbb 0.10 eee 0.05
TRAY PIN 1 BEVEL
6.350
PACKAGE IN TRAY LOADING ORIENTATION
LGA 77 0909 REV A
SUGGESTED PCB LAYOUT TOP VIEW
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LTM8062 PACKAGE DESCRIPTION
Table 3. Pin Assignment Table (Arranged by Pin Number)
PIN A1 A2 A3 A4 A5 A6 A7 PIN G1 G2 G3 G4 G5 G6 G7 NAME GND GND GND GND GND BAT BAT NAME GND GND GND GND GND GND BIAS PIN B1 B2 B3 B4 B5 B6 B7 PIN H1 H2 H3 H4 H5 H6 H7 NAME GND GND GND GND GND BAT BAT NAME GND GND GND GND GND NTC ADJ PIN C1 C2 C3 C4 C5 C6 C7 PIN J1 J2 J3 J4 J5 J6 J7 NAME GND GND GND GND GND BAT BAT NAME GND GND GND GND GND TMR FAULT PIN D1 D2 D3 D4 D5 D6 D7 PIN K1 K2 K3 K4 K5 K6 K7 NAME GND GND GND GND GND BAT BAT NAME VIN VIN VIN VINA VINA RUN CHRG PIN E1 E2 E3 E4 E5 E6 E7 PIN L1 L2 L3 L4 L5 L6 L7 NAME GND GND GND GND GND BAT BAT NAME VIN VIN VIN VINA VINA VINREG GND PIN F1 F2 F3 F4 F5 F6 F7 NAME GND GND GND GND GND BAT BAT
PACKAGE PHOTO
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Information furnished by Linear Technology Corporation is believed to be accurate and reliable. However, no responsibility is assumed for its use. Linear Technology Corporation makes no representation that the interconnection of its circuits as described herein will not infringe on existing patent rights.
19
LTM8062 TYPICAL APPLICATION
2A Solar Panel Power Manager for Charging 2-Cell 8.4V Lithium-Ion Battery, Featuring Three Hour Charge Time and 16V Peak Power Tracking. Battery Powers Two Module Regulators
VIN SOLAR POWER UNIT
VINA VIN 499k 4.7F 0.68F 100k VINREG RUN TMR NTC
LTM8062
BAT BIAS CHRG FAULT ADJ 412k 642k 2-CELL Li-Ion (2 4.2V) BATTERY
LTM8023
VOUT
NTC 10k B = 3380
LTM8021
VOUT
GND
8062 TA04
RELATED PARTS
PART NUMBER LTM4600 LTM4600HVMPV LTM4601/ LTM4601A LTM4602 LTM4603 LTM4604A LTM4608A LTM8020 LTM8022 LTM8023 LTM8025 LTM8021 DESCRIPTION 10A DC/DC Module Regulator Military Plastic 10A DC/DC Module Regulator 12A DC/DC Module Regulator with PLL, Output Tracking/Margining and Remote Sensing 6A DC/DC Module Regulator COMMENTS Basic 10A DC/DC Module, 15mm x 15mm x 2.8mm LGA -55C to 125C Operation, 15mm x 15mm x 2.8mm LGA Synchronizable, PolyPhase Operation, LTM4601-1 Version has no Remote Sensing Pin Compatible with the LTM4600
6A DC/DC Module Regulator with PLL and Output Synchronizable, PolyPhase Operation, LTM4603-1 Version has no Remote Tracking/Margining and Remote Sensing Sensing, Pin Compatible with the LTM4601 4A Low VIN DC/DC Module Regulator 8A Low VIN DC/DC Module Regulator 200mA, 36V DC/DC Module Regulator 1A, 36V DC/DC Module Regulator 2A, 36V DC/DC Module Regulator 3A, 36V DC/DC Module Regulator 500mA, 36V DC/DC Module Regulator 2.375V VIN 5V, 0.8V VOUT 5V, 9mm x 15mm x 2.3mm LGA 2.375V VIN 5V, 0.8V VOUT 5V, 9mm x 15mm x 2.8mm LGA EN55022 Class B Compliant, Fixed 450kHz Frequency, 1.25V VOUT 5V, 6.25mm x 6.25mm x 2.32mm LGA Adjustable Frequency, 0.8V VOUT 5V, 9mm x 11.25mm x 2.82mm LGA, Pin Compatible to the LTM8023 Adjustable Frequency, 0.8V VOUT 5V, 9mm x 11.25mm x 2.82mm LGA, Pin Compatible to the LTM8022 0.8V VOUT 24V, 9mm x 15mm x 4.32mm LGA EN55022 Class B Compliant, Fixed 1.1MHz Frequency, 0.8V VOUT 5V, 6.25mm x 11.25mm x 2.82mm LGA
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20 Linear Technology Corporation
(408) 432-1900 FAX: (408) 434-0507
LT 0810 * PRINTED IN USA
1630 McCarthy Blvd., Milpitas, CA 95035-7417
www.linear.com
(c) LINEAR TECHNOLOGY CORPORATION 2010

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