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NCP1835 Integrated Li-Ion Charger
NCP1835 is an integrated linear charger specifically designed to charge 1-cell Li-Ion batteries with a constant current, constant voltage (CCCV) profile. It can charge at currents of up to 1.0 A. Its low input voltage capability, adjustable charge current, ability to maintain regulation without a battery, and its onboard thermal foldback make it versatile enough to charge from a variety of wall adapters. The NCP1835 can charge from a standard voltage-source wall adapter as a CCCV charger, or from a current limited adapter to limit power dissipation in the pass device.
Features
http://onsemi.com MARKING DIAGRAMS
* * * * * * * * * * * * * * * * * * *
Integrated Voltage and Current Regulation No External MOSFET, Sense Resistor or Blocking Diode Required Charge Current Thermal Foldback Integrated Pre-charge Current for Conditioning Deeply Discharged Battery Integrated End-of-Charge (EOC) Detection 1% Voltage Regulation 4.2 V or 4.242 V Regulated Output Voltage Regulation Maintained without a Battery Present Programmable Full Charge Current 300 - 1000 mA Open-Drain Charger Status and Fault Alert Flags 2.8 V Output for AC Present Indication and Powering Charging Subsystems Minimum Input Voltage of 2.4 V Allows Use of Current Limited Adapters Automatically Recharging if Battery Voltage Drops after Charging Cycle is Completed Low Profile 3x3 mm DFN Package Pb-Free Packages are Available
1
1835 4200 ALYWG G
DFN 3x3 MN SUFFIX CASE 485C
1
1835 4242 ALYWG G
1835 = Device Code 4200 = 4.2 V 4242 = 4.242 V A = Assembly Location L = Wafer Lot Y = Year W = Work Week G = Pb-Free Package (Note: Microdot may be in either location)
Typical Applications
Cellular Phones PDAs, MP3 Players Stand-Alone Chargers Battery Operated Devices
PIN CONNECTIONS
VCC FAULT CFLG TIMER GND 1 2 3 4 5 (Top View) DFN 3x3 10 BAT 9 8 7 6 VSNS ISEL V2P8 EN
ORDERING INFORMATION
See detailed ordering and shipping information in the package dimensions section on page 15 of this data sheet.
(c) Semiconductor Components Industries, LLC, 2006
1
May, 2006 - Rev. 4
Publication Order Number: NCP1835/D
NCP1835
Vin
CFLG
EN V2P8 NCP1835
Microprocessor
FAULT Vin 4.7 mF Cin VCC
VSNS BAT GND
ISEL TIMER 15 nF CT
0.1 mF C2p8
4.7 mF Cout
80 k RISEL GND
Figure 1. Typical Application Circuit
PIN FUNCTION DESCRIPTION
Pin 1 2 3 Symbol VCC FAULT CFLG Description Input Supply Voltage. Provides power to the charger. This pin should be bypassed with at least a 4.7 mF ceramic capacitor to ground. An open-drain output indicating fault status. This pin is pulled LOW under any fault conditions. A FAULT condition resets the counter. An open-drain output indicating charging or end-of-charge states. The CFLG pin is pulled LOW when the charger is charging a battery. It is forced open when the charge current drops to IEOC. This high impedance mode will be latched until a recharge cycle or a new charge cycle starts. Connecting a timing capacitor, CTIME between this pin and ground to set end-of-charge timeout timer. TIMEOUT = 14*CTIME/1.0 nF (minute). The total charge for CC and CV mode is limited to the length of TIMEOUT. Trickle Charge has a time limit of 1/8 of the TIMEOUT period. Ground pin of the IC. For thermal consideration, it is recommended to solder the exposed metal pad on the backside of the package to ground. Enable logic input. Connect the EN pin to LOW to disable the charger or leave it floating to enable the charger. 2.8 V reference voltage output. This pin outputs a 2.8 V voltage source when an adapter is present. The maximum loading for this pin is 2.0 mA. The full charge current (IFCHG) can be set by connecting a resistor, RISEL, from the ISEL pin to ground. IFCHG = (0.8*105 / RISEL) A, the pre-charge current IPC = (0.1*IFCHG) A and the end-of-charge threshold current IEOC = (0.1*IFCHG) A. For best accuracy, a resistor with 1% tolerance is recommended. Battery voltage sense pin. Connect this as close as possible to the battery input connection. Charge current output. A minimum 4.7 mF capacitor is needed for stability when the battery is not attached.
4
TIMER
5 6 7 8
GND EN V2P8 ISEL
9 10
VSNS BAT
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NCP1835
VCC Startup, Control & Clamp V2P8
V2P8
BAT
Temp IREF CC Control CV VREF Vbat Resistor Dividers VSNS ISEL
VCC Resistor Bias Circuits Dividers
VREF CFLG LOGIC FAULT
Recharge Comp
VREF
Precharge Comp
VREF TIMER Chip Enable
Timer Comp
VREF
EN
TIMER
GND
Figure 2. Detailed Block Diagram MAXIMUM RATINGS
Rating Supply Voltage Status Flag Output Pins Voltage Range for Other Pins Current Out from BAT Pin Thermal Characteristics Thermal Resistance, Junction-to-Air (Note 3) Power Dissipation, TA = 25C (Note 3) Moisture Sensitivity (Note 4) Operating Ambient Temperature Storage Temperature ESD Human Body Model Machine Model Symbol VCC VFAULT, VCFLG Vio IO RqJA PD MSL TA Tstg HBM MM Value 7.0 7.0 5.5 1.2 68.5 1.09 Level 1 -20 to 70 -55 to 125 2000 200 C C V V Unit V V V A C/W W
Stresses exceeding Maximum Ratings may damage the device. Maximum Ratings are stress ratings only. Functional operation above the Recommended Operating Conditions is not implied. Extended exposure to stresses above the Recommended Operating Conditions may affect device reliability. 1. This device series contains ESD protection and is tested per the following standards: Human Body Model (HBM) per JEDEC standard: JESD22-A114. Machine Model (MM) per JEDEC standard: JESD22-A115. 2. Latchup Current Maximum Rating: 150 mA per JEDEC standard: JESD78. 3. Measure on 1 inch sq. of 1 oz. copper area. RqJA is highly dependent on the PCB heatsink area. For example, RqJA can be 38C/W on 1 inch sq. of 1 oz. copper area on 4 layer PCB that has 1 single signal layer with the additional 3 solid ground or power planes. The maximum package power dissipation limit must not be exceeded:
PD +
TJ(max) * TA RqJA
with RqJA = 68.5C/W, TJ(max) = 100C, PD = 1.09 W. 4. Moisture Sensitivity Level per IPC/JEDEC standard: J-STD-020A.
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NCP1835
ELECTRICAL CHARACTERISTICS (Typical values are tested at VCC = 5.0 V and room temperature, maximum and minimum values are guaranteed over 0C to 70C with a supply voltage in the range of 4.3 V to 6.5 V, unless otherwise noted.)
Characteristic VCC SUPPLY Operating Supply Range Rising VCC Threshold Falling VCC Lockout Threshold Quiescent VCC Pin Supply Current Shutdown (EN = Low) Normal Operation (EN = High) Battery Drain Current Manual Shutdown (VCC = 5.0 V, VSNS = 4.0 V, EN = Low) CHARGING PERFORMANCE Regulated Output Voltage in Constant Voltage (CV) Mode 4.2 V Version, ICHG = 10 mA 4.242 V Version, ICHG = 10 mA Dropout Voltage (VBAT = 3.7 V, ICHG = 0.5 A) Pre-Charge Threshold Voltage Pre-Charge Current (RISEL = 80 kW, VBAT = 2.0 V) Recommended Full Charge Current Full-Charge Current in Constant Current (CC) Mode (RISEL = 80 kW, VBAT = 3.7 V) End-of-Charge Threshold (RISEL = 80 kW, VBAT = VREG) Recharge Voltage Threshold Thermal Foldback Limit (Junction Temperature) (Note 5) OSCILLATOR Oscillation Period (CTIME = 15 nF) STATUS FLAGS CFLG Pin Recommended Maximum Operating Voltage FAULT Pin Recommended Maximum Operating Voltage CFLG Pin Sink Current (VCFLG = 0.8 V) FAULT Pin Sink Current (VFAULT = 0.8 V) 5. Guaranteed by design. Not tested in production. VCFLG VFAULT ICFLG IFAULT - - 5.0 5.0 - - - - 6.5 6.5 - - V V mA mA TOSC 2.4 3.0 3.6 ms VREG 4.158 4.200 - VPC IPC IFCHG IFCHG IEOC VRECH TLIM - 2.52 78 300 0.9 78 3.9 - 4.200 4.242 200 2.8 100 - 1.0 100 4.03 100 4.242 4.284 300 3.08 122 1000 1.1 122 4.155 - mV V mA mA A mA V C V VCC VRISE VFALL IVCC IVCC IBMS 2.8 3.0 2.0 - - - - 3.4 2.4 30 1.0 - 6.5 3.95 2.8 - - 3.0 V V V mA mA mA Symbol Min Typ Max Unit
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NCP1835
TYPICAL OPERATING CHARACTERISTICS
VREG, REGULATED OUTPUT VOLTAGE (V) VREG, REGULATED OUTPUT VOLTAGE (V) 4.30 4.25 4.20 4.15 4.10 4.05 4.00 0 0.2 0.4 0.6 0.8 1 ICHG, CHARGE CURRENT (A) VCC = 5 V RISEL = 80 k 4.2 V 4.242 V 4.30 4.25 4.20 4.15 4.10 4.05 RISEL = 80 k 4.00 4.5 5 5.5 VCC, INPUT VOLTAGE (V) 6 6.5 4.2 V 4.242 V
Figure 3. Regulated Output Voltage vs. Charge Current
VREG, REGULATED OUTPUT VOLTAGE (V) 4.30 4.242 V VISEL, ISEL VOLTAGE (V) 4.25 4.20 4.15 4.10 4.05 4.00 -50 VCC = 5 V VBAT floating -25 0 25 50 75 100 125 4.2 V
Figure 4. Regulated Output Voltage (floating) vs. Input Voltage
0.80
0.78 4.242 V
0.76
0.74
4.2 V
0.72
VBAT = 3.7 V RISEL = 80 k 5.0 5.5 6.0 6.5
0.70 4.5
TA, AMBIENT TEMPERATURE (C)
VCC, INPUT VOLTAGE (V)
Figure 5. Regulated Output Voltage vs. Temperature
Figure 6. ISEL Voltage vs. Input Voltage
3.00 2.95 2.90 2.85 2.80 2.75 2.70 4.5 4.2 V VBAT floating RISEL = 80 k IV2P8 = 0
V2P8, V2P8 VOLTAGE (V)
4.242 V
5.0
5.5
6.0
6.5
VCC, INPUT VOLTAGE (V)
Figure 7. V2P8 Voltage vs. Input Voltage
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NCP1835
TYPICAL OPERATING CHARACTERISTICS
IPC, TRICKLE CHARGE CURRENT (mA) 3.0 2.5 2.0 1.5 1.0 0.5 0.0 3.7 VBAT = 3.7 V RISEL = 80 k 3.9 4.1 4.3 4.5 4.7 4.9 5.1 5.3 5.5 120
V2P8, V2P8 VOLTAGE (V)
110
100
90 VBAT = 2.0 V RISEL = 80 k 80 4.5 5.0 5.5 6.0 6.5
VCC, INPUT VOLTAGE (V)
VCC, INPUT VOLTAGE (V)
Figure 8. V2P8 Voltage vs. Input Voltage
Figure 9. Trickle Charge Current vs. Input Voltage
IPC, TRICKLE CHARGE CURRENT (mA)
110 100 90 80 70 60 -50 VCC = 5 V VBAT = 2.0 V -25 0 25 50 75 100 125
IFCHG, FULL CHARGE CURRENT (mA)
120
1200
1100
1000
900 VBAT = 3.7 V RISEL = 80 k 800 4.5 5.0 5.5 6.0 6.5
TA, AMBIENT TEMPERATURE (C)
VCC, INPUT VOLTAGE (V)
Figure 10. Trickle Charge Current vs. Temperature
Figure 11. Full Charge Current vs. Input Voltage
4.10 VRECH, RECHARGE VOLTAGE (V)
1000 ICHG, CHARGE CURRENT (mA) 4.2 V 4.242 V
4.05
800
600
4.00
400
3.95 RISEL = 80 k 3.90 4.5 5.0 5.5 6.0 6.5
200 VCC = 5 V 0 2.5 3.0 3.5 4.0 4.5
VCC, INPUT VOLTAGE (V)
VBAT, BATTERY VOLTAGE (V)
Figure 12. Recharge Voltage vs. Input Voltage
Figure 13. Charge Current vs. Battery Voltage
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NCP1835
DETAILED OPERATING DESCRIPTION
Overview
Rechargeable Li-Ion/Polymer batteries are normally charged with a constant current (CC) until the terminal voltage reaches a fixed voltage threshold, at which point a constant voltage (CV) is applied and the current drawn by the battery decays. The charging rate is determined by the specific rating of the battery. For example, if the battery is rated at 800 mA-hours, then the recommended maximum charge rate is 800 mA. For a severely discharged cell, it takes approximately 2.5-3.5 hours to recharge the battery at the maximum rate. So, when one charges at less than the maximum charge rate, the recharge time increases. Also, the battery should not be continuously charged or the battery could age faster than necessary. Because of this, Li-Ion charging systems need to stop charging within a prescribed time limit regardless of the charge rate. The NCP1835 is a fully integrated, stand-alone 1-cell Li-Ion charger which performs the primary battery charging functions and includes a timer which will terminate charging if the battery has not completed charging within a prescribed time period. The charging rate is user programmable up to 1.0 A and the end-of-charge timer is also programmable. The NCP1835 has a thermal foldback loop which reduces the charge rate if the junction temperature is exceeded. The device also includes several outputs which can be used to drive LED indicators or interface to a microprocessor to provide status information. The adapter providing power to the charger can be a standard fixed output voltage such as a 5.0 V wall adapter or it can be a simple current limited adapter. The NCP1835 comes in two versions with output voltage regulation thresholds of 4.2 or 4.242 V depending on the requirements of the specific battery pack being used. The user determines the charge current by selecting the resistor RISEL and determines the length of the end-of-charge timeout timer by selecting the capacitor, CTIME.
Charging Operation
Figure 13 outlines the charging algorithm of the NCP1835 and Figure 14 graphically illustrates this. When the charger is powered up and the input voltage rises above the power-on, rising threshold (nominally 3.4 V), the charger initiates the charging cycle. The NCP1835 first determines the cell voltage. If it is less than the pre-charge threshold (2.8 V), the IC
recognizes the battery as severely discharged. In this state, the NCP1835 pre-conditions (trickle charges) the battery by charging it at 10% of the full charge rate (IPC). This slow charge prevents the battery from being damaged from high fast charge currents when it is in a deeply discharged state. The battery voltage should be trickle charged up to 2.8 V before 1/8 of the preset end-of-charge time is expired. If it cannot reach this voltage, than the battery is possibly shorted or damaged. Therefore, the NCP1835 stops charging and the pre-charge timeout signal asserts the FAULT flag. Once the cell voltage crosses the pre-charge threshold, the device will transition to normal (full-rate) charging at 100% of the programmed full rate charge current (IFCHG). As the NCP1835 charges the battery, the cell voltage rises until it reaches the VREG threshold, (4.2 or 4.242 V). At the maximum charge rate, it normally takes about 1 hour to reach this point from a fully discharged state, and the battery will be approximately 70-80% recharged. At this point, the charge transitions to constant voltage mode where the IC forces the battery to remain at a constant voltage, VREG. During this constant voltage state, the current required to maintain VREG steadily decreases as the battery approaches full charge. Charge current eventually falls to a very low value as the battery approaches a fully charged condition. The NCP1835 monitors the current into the battery until it drops to 10% of the full charge rate. This is the End-of-Charge (EOC) threshold. Normally it takes 1.5-2.5 hours to reach this point. Once the NCP1835 reaches end-of-charge it opens the CFLG pin and enters the EOC state. The IC continues to charge the battery until it reaches TIMEOUT. At that point, the NCP1835 stops charging. If the system does not reach EOC during the TIMEOUT period, the NCP1835 views this as a system fault and asserts the FAULT flag. If the battery voltage drops below the recharge threshold (which can occur if the battery is loaded), the IC reinitializes the charging sequence and begins a new charge cycle. The recharge voltage threshold, VRECH, is nominally 4.03 V. In the inhibit state, the NCP1835 continues to monitor the battery voltage, but does not charge the battery. Again, if the battery voltage drops below the recharge threshold the IC reinitializes the charging sequence and begins a new charge cycle.
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NCP1835
Power Up
Charging Flow Chart
VCC > VPOR?
N
Y POR
Initialization Reset Counter
Trickle Charge
CC Charge
CV Charge
VSNS VREG? VSNS > VPC? Y N N
Y
Ich < IEOC?
Y
N
N N 1/8 TIMEOUT? Constant Current Charge Y Constant Voltage Charge Y N TIMEOUT? TIMEOUT?
Trickle Charge
Y
EOC Indication; Set CFLG High Keep FAULT High Set FAULT Low Latch Up Charger Y VSNS < VRECH?
Charger Inhibited Reset Counter
N N EN Toggled? Y End-of-Charge or FAULT N Inhibit TIMEOUT? Y
VSNS < VRECH? Y Start Recharge
N
Figure 14. Charging Flow Chart http://onsemi.com
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NCP1835
Trickle Charge CC Charge CV Charge End of Charge Inhibit Recharging
Vin
VRISE
Time VBAT
VREG VRECH VREG
VPC
Time Icharge
ICHG ICHG
IPC
IEOC
Time CFLG
Time FAULT
Time V2P8
2.8 V
Time 0 Figure 15. Typical Charging Diagram Table 1. Charge Status
Condition Trickle, Constant Current and Constant Voltage Charge End-of-Charge or Shutdown Mode Timeout Fault, VISEL < 0.35 V or VISEL > 1.4 V CFLG Low High High FAULT High High Low
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NCP1835
Charge Status Indicator (CFLG) Enable/Disable (EN)
CFLG is an open-drain output that indicates battery charging or End-of-Charge (EOC) status. It is pulled low when charging in constant current mode and constant voltage mode. It will be forced to a high impedance state when the charge current drops to IEOC. When the charger is in shutdown mode, CFLG will also stay in the high impedance state.
Fault Indicator (FAULT)
Pulling the EN pin to GND disables the NCP1835. In shutdown mode, the internal reference, oscillator, and control circuits are all turned off. This reduces the battery drain current to less than 3.0 mA and the input supply current to 30 mA. Floating the EN pin enables the charger.
Thermal Foldback
ICHG, CHARGE CURRENT
FAULT is an open-drain output that indicates that a charge fault has occurred. It has two states: low or high impedance. In a normal charge cycle, it stays in a high impedance state. At fault conditions, it will be pulled low and terminate the charge cycle. A timeout fault occurs when the full charge or pre-charge timeouts are violated, or if the voltage on ISEL is greater than 1.4 V or lower than 0.35 V. There are two ways to get the charger out of a fault condition and back to a normal charge cycle. One can either toggle the EN pin from GND to a floating state or reset the input power supply.
Adapter Present Indicator (V2P8)
An internal thermal foldback loop reduces the programmed charge current proportionally if the die temperature rises above the preset thermal limit (nominally 100C). This feature provides the charger protection from over heating or thermal damage. Figure 16 shows the full charge current reduction due to die temperature increase across the thermal foldback limit. For a charger with a 1.0 A constant charge current, the charge current starts decreasing when the die temperature hits 100C and is reduced to zero when the die temperature rises to 110C.
IFCHG X-100 mA/C
V2P8 is an input power supply presence indicator. When the input voltage, VCC, is above the power on threshold (VRISE, nominally 3.4 V) and is also 100 mV above the battery voltage, it provides a 2.8 V reference voltage that can source up to 2.0 mA. This voltage can also be used to power a microprocessor I/O.
100C TJ, JUNCTION TEMPERATURE
Figure 16. Full Charge Current vs. Junction Temperature
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NCP1835
APPLICATION INFORMATION
Input and Output Capacitor Selection
0.18 0.16 0.14 0.12 IPCHG (A) 0.10 0.08 0.06 0.04 0.02 0.00 80 100 120 140 RISEL (kW) 160 180 200
A 4.7 mF or higher value ceramic capacitor is recommended for the input bypass capacitor. For the output capacitor, when there is no battery inserted and the NCP1835 is used as an LDO with 4.2 V or 4.242 V output voltage, a 4.7 mF or higher value tantalum capacitor is recommended for stability. With the battery attached, the output capacitor can be any type with the value higher than 0.1 mF.
RISEL Resistor Selection for Programming Charge Current
A single resistor, RISEL, between the ISEL pin and ground programs the pre-charge current, full charge current, and end-of-charge detection threshold. The nominal voltage of ISEL is 0.8 V. The charge current out of BAT pin is 100,000 times the current out of ISEL pin. Therefore, the full charge current (IFCHG) is:
IFCHG + 100, 000 0.8 (A) RISEL
(eq. 1)
Figure 18. Pre-Charge Current (IPCHG) vs. Current Select Resistor (RISEL)
CTIME Selection for Programming Charge Time
IPC and IEOC are 10% of the value programmed above with the RISEL resistor. The following table and curves show the selection of the resistance value for desired currents.
Table 2. Charge Current vs. RISEL
IFCHG (mA) 300 500 600 700 800 900 1000 1.6 1.4 1.2 IFCHG (A) 1.0 0.8 0.6 0.4 0.2 0.0 80 100 120 140 RISEL (kW) 160 180 200 IPC / IEOC (mA) 30 50 60 70 80 90 100 RISEL (kW) 267 160 133.3 114.3 100 88.9 80
The NCP1835 offers an end-of-charge timeout timer to prevent the battery from continuously charging which can cause premature aging or safety issues. The timing capacitor between TIMER pin and ground, CTIME, sets the end-of-charge time, TIMEOUT, and the pre-charge timeout. This capacitor is required for proper device operation. The internal oscillator charges CTIME to 1.2 V and then discharges it to 0.6 V with 6 mA current in one period. Therefore, the period of the oscillator is:
TOSC + 2 CTIME dVc + 0.2 IC 10 6 CTIME (sec)
(eq. 2)
A 22-binary counter counts every oscillator period until it reaches the maximum number corresponding to end-of-charge time, TIMEOUT.
TIMEOUT + 2 22 TOSC + 14 CTIME (minute) 1 nF
(eq. 3)
The NCP1835 will terminate charging and give a timeout signal if the battery has not completed charging within the TIMEOUT period. The timeout signal then forces the FAULT pin low.
Figure 17. Full-Charge Current (IFCHG) vs. Current Select Resistor (RISEL)
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NCP1835
The following Table 3 shows the desired TIMEOUT vs. CTIME sizes. The CTIME is required for proper device operation.
Table 3. TIMEOUT vs. CTIME Size
CTIME (nF) 0.47 1 5.6 8.2 10 15 33 56 TIMEOUT (minute) 6.6 14 78 115 140 210 462 784
the linear charger powered with a standard constant voltage adapter. The power dissipation in the linear charger is:
Pdis + (VCC * VBAT) ICHG
(eq. 4)
Thermal Considerations
The NCP1835 is housed in a thermally enhanced 3x3 mm DFN package. In order to deliver the maximum power dissipation under all conditions, it is very important that the user solders exposed metal pad under the package to the ground copper area and then connect this area to a ground plane through thermal vias. This can greatly reduce the thermal impedance of the device and further enhance its power dissipation capability and thus its output current capability.
Charging with Constant Voltage Adapters or Current Limited Adapters
The NCP1835 can be powered from two types of regulated adapters: a traditional constant voltage type or a current limited type. Figure 19 illustrates the operation of
Trickle Charge CC Charge CV Charge
The maximum power dissipation P1 happens at the beginning of a full current charge, since this is the point that the power supply and the battery voltage have the largest difference. As the battery voltage rises during charging, the power dissipation drops. After entering the constant voltage mode, the power dissipation drops further due to the decreasing charge current. The maximum power that the linear charger can dissipate is dependent on the thermal resistance of the device. In case the device can not handle the maximum power P1, the thermal foldback loop reduces the charge current which limits the power dissipation to the sustained level P2. Figure 19 shows this. Using the adapter's current limit can provide better thermal performance than the above example. A current limited adapter operates as a constant voltage adapter before the charge current reaches the current limit. ILIM must be less than the programmed full charge current IFCHG. Once the current limit is reached, the adapter will source the current limit ILIM while its output voltage will drop to follow the battery voltage. If the application uses the adapter to power its systems while the battery is being charged, this drooping voltage can be an issue. The worst case power dissipation with a current limited adapter occurs at the beginning of the constant voltage mode, which is shown at point P3 in Figure 20. If P3 is higher than P2, the maximum power dissipation that the charger can handle, then the thermal foldback function will be activated.
Trickle Charge CC Charge CV Charge
Inhibit
Inhibit
Vin Time
Vin
VBAT
VPC
VREG
VBAT
VPC
VREG
Time
Icharge
Time
IFCHG
Icharge
Time
IFCHG ILIM
IPC
IPC
Pdis
Time
P1 P2
Pdis
P3
Time
0
Time
0
Time
Figure 19. Typical Charge Curves with a Constant Voltage Adapter
Figure 20. Typical Charge Curves with a Current Limited Adapter
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NCP1835
PCB Layout Recommendations The recommended footprint for the 3x3 mm DFN package is included on the Package Dimension page. It is critical that the exposed metal pad is properly soldered to the ground copper area and then connected to a ground plane through thermal vias. The maximum recommended thermal via diameter is 12 mils (0.305 mm). Limited by the size of the pad, six thermal vias should allow for proper thermal regulation without sacrificing too much copper area within the pad. The copper pad is the primary heatsink and should be connected to as much top layer metal as possible to minimize the thermal impedance. Figure 21 illustrates graphically the recommended connection for the exposed pad with vias.
GND
Figure 21. Recommended Footprint
The following is a NCP1835 Demo Board Schematic, Layout, and suggested Bill of Materials.
NCP1835 VCC (T8) R4 C5 D1 R5 D2 TIMER (T10) VCC FAULT CFLG TIMER GND VCC 2 R3 JP2 1 1 BAT VSNS ISEL V2P8 EN C3 R8 2 JP1 V2P8 (T4) D3 R2 C4 CFLG (T6) GND (T9) C1 C2 GND (T2) R9 R1 + - VSNS (T7) Li-Ion Battery VBAT (T1)
FAULT (T5)
Figure 22. Demo Board Schematic
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NCP1835
Figure 23. Silkscreen Layer
Figure 24. Top Layer
Figure 25. Bottom Layer http://onsemi.com
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NCP1835
Table 4. Bill of Materials
Item 1 2 3 4 5 6 8 9 10 11 12 13 14 15 16 17 Qty. 1 1 2 1 2 1 1 1 1 1 1 1 1 1 5 2 Part Description NCP1835 Integrated Li-Ion Charger (DFN-10) Chip Resistor "1% 0 W (0603) Chip Resistor "1% 160 kW (0603) Chip Resistor "1% 100 kW (0603) Chip Resistor "1% 1.0 kW (0603) Chip Resistor "1% 432 W (0603) Chip Capacitor 1.0 mF/16 V, "20% (0805) Chip Capacitor 4.7 mF/10 V, "20% (3528-21) Chip Capacitor 0.1 mF/10 V, "10% (0402) Chip Capacitor 15 nF/16 V, "10% (0402) Chip Capacitor 4.7 mF/25 V, "20% (0805) SMT Chip LED Red SMT Chip LED Green SMT Chip LED Yellow Test Pin Header Pin Pinch = 2.54 mm Designators U1 R1 R2, R9 R3 R4, R5 R8 C1 C2 C3 C4 C5 D1 D2 D4 T1, T2, T7, T8, T9, T10 JP1, JP2 Suppliers ON Semiconductor Vishay Vishay Vishay Vishay Vishay Panasonic Kemet Panasonic Panasonic Panasonic Agilent Agilent Agilent AMP/Tyco AMP/Tyco Part Number NCP1835 CRCW06030R00F CRCW06031603F CRCW06031003F CRCW06031001F CRCW06034320F ECJGVB1C105M T491B475K010AS ECJ0EB1A104K ECJ0EB1C153K ECJ2FB1E475M HSMH-C150 HSMG-C150 HSMY-C150 4-103747-0 4-103747-0
ORDERING INFORMATION
Device NCP1835MN20R2 NCP1835MN20R2G NCP1835MN24T2 NCP1835MN24T2G Voltage Option 4.2 V 4.2 V 4.242 V 4.242 V Package DFN-10 DFN-10 (Pb-Free) DFN-10 DFN-10 (Pb-Free) Shipping 3000 / Tape & Reel 3000 / Tape & Reel 3000 / Tape & Reel 3000 / Tape & Reel
For information on tape and reel specifications, including part orientation and tape sizes, please refer to our Tape and Reel Packaging Specifications Brochure, BRD8011/D.
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NCP1835
PACKAGE DIMENSIONS
DFN10, 3 x 3mm, 0.5mm Pitch CASE 485C-01 ISSUE A
EDGE OF PACKAGE
D
A B L1 DETAIL A Bottom View (Optional)
E
PIN 1 REFERENCE 2X 2X
NOTES: 1. DIMENSIONING AND TOLERANCING PER ASME Y14.5M, 1994. 2. CONTROLLING DIMENSION: MILLIMETERS. 3. DIMENSION b APPLIES TO PLATED TERMINAL AND IS MEASURED BETWEEN 0.25 AND 0.30 MM FROM TERMINAL. 4. COPLANARITY APPLIES TO THE EXPOSED PAD AS WELL AS THE TERMINALS. 5. TERMINAL b MAY HAVE MOLD COMPOUND MATERIAL ALONG SIDE EDGE. MOLD FLASHING MAY NOT EXCEED 30 MICRONS ONTO BOTTOM SURFACE OF TERMINAL b. 6. DETAILS A AND B SHOW OPTIONAL VIEWS FOR END OF TERMINAL LEAD AT EDGE OF PACKAGE. DIM A A1 A3 b D D2 E E2 e K L L1 MILLIMETERS MIN MAX 0.80 1.00 0.00 0.05 0.20 REF 0.18 0.30 3.00 BSC 2.45 2.55 3.00 BSC 1.75 1.85 0.50 BSC 0.19 TYP 0.35 0.45 0.00 0.03
0.15 C
0.15 C 0.10 C
DETAIL B
(A3) A1 A
SEATING PLANE
10X
0.08 C SIDE VIEW A1 C
DETAIL B Side View (Optional)
D2
10X
DETAIL A 5
L
1
e 2.6016
E2
10X
K 2.1746
10 10X 6
b BOTTOM VIEW
10X
0.10 C A B 0.05 C
NOTE 3
0.5651
0.3008
*For additional information on our Pb-Free strategy and soldering details, please download the ON Semiconductor Soldering and Mounting Techniques Reference Manual, SOLDERRM/D.
ON Semiconductor and are registered trademarks of Semiconductor Components Industries, LLC (SCILLC). SCILLC reserves the right to make changes without further notice to any products herein. SCILLC makes no warranty, representation or guarantee regarding the suitability of its products for any particular purpose, nor does SCILLC assume any liability arising out of the application or use of any product or circuit, and specifically disclaims any and all liability, including without limitation special, consequential or incidental damages. "Typical" parameters which may be provided in SCILLC data sheets and/or specifications can and do vary in different applications and actual performance may vary over time. All operating parameters, including "Typicals" must be validated for each customer application by customer's technical experts. SCILLC does not convey any license under its patent rights nor the rights of others. SCILLC products are not designed, intended, or authorized for use as components in systems intended for surgical implant into the body, or other applications intended to support or sustain life, or for any other application in which the failure of the SCILLC product could create a situation where personal injury or death may occur. Should Buyer purchase or use SCILLC products for any such unintended or unauthorized application, Buyer shall indemnify and hold SCILLC and its officers, employees, subsidiaries, affiliates, and distributors harmless against all claims, costs, damages, and expenses, and reasonable attorney fees arising out of, directly or indirectly, any claim of personal injury or death associated with such unintended or unauthorized use, even if such claim alleges that SCILLC was negligent regarding the design or manufacture of the part. SCILLC is an Equal Opportunity/Affirmative Action Employer. This literature is subject to all applicable copyright laws and is not for resale in any manner.
PUBLICATION ORDERING INFORMATION
LITERATURE FULFILLMENT: Literature Distribution Center for ON Semiconductor P.O. Box 5163, Denver, Colorado 80217 USA Phone: 303-675-2175 or 800-344-3860 Toll Free USA/Canada Fax: 303-675-2176 or 800-344-3867 Toll Free USA/Canada Email: orderlit@onsemi.com N. American Technical Support: 800-282-9855 Toll Free USA/Canada Europe, Middle East and Africa Technical Support: Phone: 421 33 790 2910 Japan Customer Focus Center Phone: 81-3-5773-3850 ON Semiconductor Website: www.onsemi.com Order Literature: http://www.onsemi.com/orderlit For additional information, please contact your local Sales Representative
http://onsemi.com
16
EE EE EE
10X
CCC CCC CCC
EXPOSED Cu MOLD CMPD
TOP VIEW
A3
SOLDERING FOOTPRINT*
1.8508
3.3048
0.5000 PITCH
DIMENSIONS: MILLIMETERS
NCP1835/D

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