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LT3464 Micropower Boost Converter with Schottky and Output Disconnect in ThinSOTTM
FEATURES
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DESCRIPTIO
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Tiny Solution Size Low Quiescent Current * 25A in Active Mode * 0.5A in Shutdown Mode Internal 115mA, 36V Switch Integrated Schottky Diode Integrated PNP Output Disconnect with Short-Circuit Protection Internal Reference Override Pin 16V at 8mA from 3.6V Input 12V at 20mA from 5V Input Input Range: 2.3V to 10V High Output Voltage: Up to 34V Low Profile (1mm) SOT-23 Package
APPLICATIO S
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OEL Panel Bias LCD Bias Handheld Computers Battery Backup Digital Cameras Cellular Phones
The LT(R)3464 is a micropower step-up DC/DC converter with integrated Schottky diode and output disconnect packaged in an 8-lead low profile (1mm) SOT-23. The small package size, high level of integration, and the use of tiny SMT components yield a solution size of less than 40mm2. The LT3464 has a typical current limit of 115mA as well as fast switching speed to allow the use of a chip inductor and small ceramic capacitors. The internal PNP disconnects the output load from the input during shutdown, and also provides output short-circuit protection. An auxiliary reference input allows the user to override the internal 1.25V feedback reference with any lower value, allowing full control of the output voltage during operation. This device features a low 25A quiescent current, which is further reduced to less than 0.5A in shutdown. A current limited fixed off-time control scheme conserves operating current, resulting in high efficiency over a broad range of operating current. The rugged 36V switch and output disconnect circuitry allow outputs up to 34V to be easily generated in a simple boost topology.
, LTC and LT are registered trademarks of Linear Technology Corporation. ThinSOT is a trademark of Linear Technolgy Corporation
TYPICAL APPLICATIO
VIN 2.3V TO 10V VIN
22H
90 VIN = 8.4V 80
SW
1F
CTRL LT3464 SHDN FB GND CAP
0.22F
EFFICIENCY (%)
OUT
VOUT 16V
70 60 50 40 30 0.01
0.33F
3.48M
294k
3464 TA01a
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Efficiency
VIN = 4.2V 0.1 1 10 LOAD CURRENT (mA) 100
3634 TA01b
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LT3464
ABSOLUTE
(Note 1)
AXI U RATI GS
PACKAGE/ORDER I FOR ATIO
TOP VIEW CTRL 1 FB 2 OUT 3 GND 4 8 SHDN 7 VIN 6 SW 5 CAP
VIN, SHDN, CTRL Voltage ........................................ 10V OUT, CAP Voltage .................................................... 36V SW Voltage .............................................................. 36V FB Voltage ................................................................. 6V Maximum Junction Temperature .......................... 125C Operating Temperature Range (Note 2) .. - 40C to 85C Storage Temperature Range ..................-65C to 150C Lead Temperature (Soldering, 10 sec).................. 300C
ORDER PART NUMBER LT3464ETS8 TS8 PART MARKING LTG2
TS8 PACKAGE 8-LEAD PLASTIC SOT-23
TJMAX = 125C, JA = 140C/W, JC = 85C/W
Consult LTC Marketing for parts specified with wider operating temperature ranges.
The q denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25C. VIN = 3.6V, unless otherwise noted. (Note 2)
PARAMETER Minimum Input Voltage Quiescent Current FB Comparator Trip Voltage FB Comparator Hysteresis FB Pin Bias Current FB Voltage Line Regulation Switch Off Time Switch Leakage Current Switch VCESAT Switch Current Limit Schottky Forward Voltage Schottky Reverse Leakage PNP Disconnect VCAP-OUT PNP Disconnect Q Current PNP Disconnect Leakage PNP Disconnect Current Limit SHDN Pin Current SHDN Input Voltage High SHDN Input Voltage Low CTRL Pin Bias Current CTRL to FB Offset VCTRL = 0.5V, VFB = 1V VCTRL = 0.5V (Note 4)
q
ELECTRICAL CHARACTERISTICS
CONDITIONS Not Switching VSHDN = 0.2V VFB Falling, VCTRL = 3.6V VFB = 1.25V, VCTRL = 3.6V 2.3V < VIN < 10V VCAP-VIN = 5V VCAP-VIN = 0V VSW = 36V ISW = 80mA
q
MIN
TYP 2.0 25 0.01
MAX 2.3 36 0.5 1.275 30 0.1
UNITS V A A V mV nA %/V ns s
1.215
1.250 10 3 0.05 250 1.0 0.02 190
q
1 300 140 750 10
85 ISCHOTTKY = 110mA VCAP-SW = 36V IOUT = 200A IOUT = 10mA IOUT = 0, VCAP = 36V (Note 3) SHDN = 0.2, VCAP = 10V, VOUT = 0V VCAP = 10V, VOUT = 0V VSHDN = 3.6V 2.3 25
115 600 1 100 190 1.5 0.1 45 5
5 5 75 10 0.2
6 2
80 7
Note 1: Absolute Maximum Ratings are those values beyond which the life of a device may be impaired. Note 2: The LT3464E is guaranteed to meet performance specifications from 0C to 70C. Specifications over the - 40C to 85C operating temperature range are assured by design, characterization and correlation with statistical process controls.
Note 3: Current consumed by Disconnect PNP when there is no load on the OUT pin. Note 4: This figure is computed according to ((VFB falling + VFB rising)/2) -VCONTROL.
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A mV mA mV A mV mV A A mA A V V nA mV
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LT3464 TYPICAL PERFOR A CE CHARACTERISTICS
Switch Saturation Voltage ISW = 80mA
220 200
SWITCH CURRENT (mA) SWITCH VOLTAGE (mV)
180 160 140 120 100 -50
SWITCH OFF-TIME (ns)
-25
0 25 50 TEMPERATURE (C)
Minimum Switch On-Time
100 90 80
SWITCH OFF-TIME (s) SWITCH ON-TIME (ns)
70 60 50 40 30 20 10 0 -50 -25 0 25 50 TEMPERATURE (C) 75 100
3464 G04
VOLTAGE DROP (mV)
Output Disconnect Quiescent Current
2.0 1.8
QUIESCENT CURRENT (A)
1.6
CURRENT LIMIT (mA)
1.4 1.2 1.0 0.8 0.6 0.4 0.2 0 -50 -25 0 25 50 TEMPERATURE (C) 75 100
3464 G07
40 30 20 10 0 -50
VOLTAGE DROP (mV)
UW
75 100
3464 G01
Switch Current Limit
140 120 100 80 60 40 20 0 -50 400 350 300 250 200 150 100 50 -25 0 25 50 TEMPERATURE (C) 75 100
3464 G02
Switch Off-Time, VCAP - VIN = 5V
0 -50
-25
0 25 50 TEMPERATURE (C)
75
100
3464 G03
Switch Off-Time, VCAP - VIN = 0V
1.3 1.2 1.1 1.0 0.9 0.8 0.7 0.6 0.5 -50 -25 0 25 50 TEMPERATURE (C) 75 100
3464 G05
Output Disconnect Voltage Drop
300 250 IOUT = 10mA 200 150 IOUT = 200A 100 50 0 -50
-25
0 25 50 TEMPERATURE (C)
75
100
3464 G06
Output Disconnect Current Limit
60 50 300 250 200 150 100 50 0
Output Disconnect Voltage Drop
-25
0 25 50 TEMPERATURE (C)
75
100
3464 G08
0
10 20 COLLECTOR CURRENT (mA)
30
3464 G09
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LT3464 TYPICAL PERFOR A CE CHARACTERISTICS
Schottky Forward Drop at ID = 110mA
800 750
SCHOTTKY CURRENT (mA) LEAKAGE CURRENT (A)
700
VOLTAGE DROP (mV)
650 600 550 500 450 400 350 300 -50 -25 0 25 50 TEMPERATURE (C) 75 100
3464 G10
Quiescent Current
30 28
QUIESCENT CURRENT (A) SHUTDOWN PIN CURRENT (A)
QUIESCENT CURRENT (nA)
26 24 22 20 18 16 14 12 10 -50 -25 0 25 50 TEMPERATURE (C) 75 100
3464 G12
Quiescent Current in Regulation with No Load
70 60
QUIESCENT CURRENT (A)
2.4 2.2 2.0 1.8 1.6 1.4
FB PIN VOLTAGE (V)
50 40 30 20 10 0 6
SHDN PIN VOLTAGE (V)
VIN = 5V FRONT PAGE SCHEMATIC 8 10 14 12 VOUT (V) 16 18 20
4
UW
3464 G18
Schottky Forward Voltage
250 20
Schottky Reverse Leakage
VCAP - SW = 36V
200
16
150
12
100
8
50
4
0 200
300
400 500 600 700 FORWARD VOLTAGE (mV)
800
3464 G11
0 -50
-25
0 25 50 TEMPERATURE (C)
75
100
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Shutdown Pin Current VSHDN = 3.6V
12 10 8 6 4 2 0 -50 16 14 12 10 8 6 4 2 -25 0 25 50 TEMPERATURE (C) 75 100
3464 G13
Quiescent Current in Shutdown Mode
0 -50
-25
0 25 50 TEMPERATURE (C)
75
100
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SHDN Pin Threshold Voltage
3.0 2.8 2.6 1.28 1.30
FB Pin Voltage
1.26
1.24
1.22
1.2 1.0 -50 -25 0 25 50 TEMPERATURE (C) 75 100
3464 G15
1.20 -50
-25
0 25 50 TEMPERATURE (C)
75
100
3464 G16
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LT3464 TYPICAL PERFOR A CE CHARACTERISTICS
FB Pin Voltage vs CTRL Pin Voltage
1.50 1.25 8 7 CTRL PIN
FB PIN VOLTAGE (V)
BIAS CURRENT (nA)
1.00 0.75 0.50 0.25 0
HYSTERESIS (mV)
0
0.25
0.5 0.75 1.0 1.25 1.5 CONTROL PIN VOLTAGE (V)
PI FU CTIO S
CTRL (Pin 1): Internal Reference Override Pin. This allows the FB voltage to be externally set between 0V and 1.25V. Tie this pin to above 1.5V (VIN for example) to use the internal 1.25V reference.
R2 VOUT = VCTRL + 1 R1
when VCTRL is less than 1.25V (see Figure 4) FB (Pin 2): Feedback Pin. The LT3464 regulates its feedback pin to 1.25V if the internal reference is used or to VCTRL if the CTRL pin is between 0V and 1.25V. Connect the feedback resistor divider tap to this pin. Set the output voltage by selecting R1 and R2 (see Figure 4).
V R2 = R1 OUT - 1 VREF
OUT (Pin 3): PNP Collector. This is the output of the Output Disconnect circuit. Bypass this pin with at least a 0.1F capacitor connected to the CAP pin or to ground.
UW
3464 G17
FB and CTRL Pin Bias Currents
12 10 8 6 4 2
FB Pin Hysteresis
6 5 4 FEEDBACK PIN 3 2 1
1.75
0 -50
-25
0 25 50 TEMPERATURE (C)
75
100
3464 G18
0 -50
-25
0 25 50 TEMPERATURE (C)
75
100
3464 G19
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GND (Pin 4): Ground. Tie this pin directly to the ground plane. CAP (Pin 5): PNP Emitter and Schottky Cathode. This pin connects to the output capacitor, and optionally to the external phase-lead capacitor. SW (Pin 6): Switch Pin and Schottky Anode. This is the collector of the internal NPN power switch. Minimize the metal trace area connected to the pin to minimize EMI. VIN (Pin 7): Input Supply Pin: Bypass this pin with a capacitor located as close to the device as possible. SHDN (Pin 8): Shutdown Pin. This pin is used to put the device in shutdown mode. Tie the pin low to shut down the LT3464. Tie high for normal operation See the electrical specifications for the required voltages.
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LT3464
BLOCK DIAGRA
FB
2
CTRL
1
SHDN 8
OPERATIO
The LT3464 uses a constant off-time control scheme in conjunction with Burst Mode(R) operation to provide high efficiency over a wide range of output current. Operation can best be understood by studying the Block Diagram. When the FB pin voltage is lower than the 1.25V reference, the hysteretic comparator enables the power section, causing the chip to start switching, thus charging the output capacitor. When the output voltage increases enough to overcome the hysteresis, the feedback comparator shuts off the power section leaving only low power circuitry running until the output voltage falls again. This cycle repeats, keeping the output voltage within a small window. The switching action is as follows: The switch turns on, and current through it starts to ramp up until the
Burst Mode is a registered a trademark of Linear Technolgy Corporation.
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VIN 7 SW 6 CAP 5 OUT 3 CPL S R DELAY Q Q
+ - -
1.25V
OUT
ANTI SAT
+
OUT 12mV
-
VREF 4
0.1
3464 BD
GND
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point where the current limit is reached, at which point the switch turns off for a fixed amount of time. While the switch is off the inductor is delivering current to the load. When the off time expires, the switch turns on again until the current limit is reached, and the cycle repeats. This chip includes an internal power Schottky diode and a PNP transistor for output disconnect. The PNP transistor disconnects the load from the input during shutdown. The PNP control circuitry is designed to keep the PNP out of saturation across a wide range of current, to keep quiescent current to a minimum and to provide current limiting to protect the chip during short-circuit conditions.
LT3464
SWITCHI G TI E WAVEFOR S
Operating Waveforms Start up Waveforms
IL 0.1A/DIV
VOUT 50mV/DIV
VIN = 5V VOUT = 20V ILOAD = 1mA L = 22H
5s/DIV
SHDN
5V/DIV
VIN = 5V GND 1ms/DIV
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IL 0.1A/DIV
VOUT 10V/DIV
50s/DIV
Shutdown Waveforms
CAP PIN VOLTAGE VOUT: THE OUTPUT DISCONNECT ALLOWS VOUT TO BE AT GROUND DURING SHUTDOWN
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LT3464
APPLICATIO S I FOR ATIO
Choosing an Inductor
The low current limit and fast switching of the LT3464 allow the use of very small surface mount inductors. The minimum inductor size that may be used in a given application depends on required efficiency and output current. Some inductors that work with the LT3464 are listed in Table 1, although there are many other manufacturers and devices that can be used. Consult each manufacturer for more detailed information and for their entire selection of related parts. Many different sizes and shapes are available.
Table 1. Recommended Inductors
PART NUMBER LQH32CN680K53 LQH32CN470K53 LQH32CN220K53 ELJPC220KF ELJPA470KF CMD4D11-47 H 68 47 22 22 47 47 DCR () 2.2 1.3 0.71 4.0 2.25 2.2 CURRENT (mA) 130 170 250 160 135 180 MANUFACTURER Murata 814-237-1431 www.murata.com Panasonic 714-373-7334 www.panasonic.com Sumida 847-956-0666 www.Sumida.com Taiyo Yuden 408-573-4150 www.t-yuden.com
LB2016-220 LEM2520-220 LEM2520-330 LEMC2520-220 LEMC2520-330 LEMF2520-220 LEMC3225-680 LEMC3225-101
22 22 33 22 33 22 68 100
1.0 5.5 7.1 2.7 4.8 1.2 3.3 4.3
105 125 110 160 120 105 120 100
The following set of formulas can be used to calculate maximum output current given VIN, VOUT and L values. Inequality 1 is used to determine if the LT3464 is operating
17.5 15.0 L = 47H 12.5 L = 22H L = 10H
25 L = 47H
20
IOUT (mA)
IOUT (mA)
IOUT (mA)
15
10.0 7.5 5.0
10
2.5 0 10
L = 4.7H
15
20
25 VOUT (V)
30
35
3464 F01
Figure 1. Maximum Output Current VIN = 3.6V
Figure 2. Maximum Output Current VIN = 5V
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in discontinuous mode. If the left hand side of inequality 1 evaluates to less than tOFF, then use Equation 3 to calculate maximum output current. Otherwise, use Equation 2. This inequality is true when the LT3464 is operating in discontinuous mode.
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LILIM < tOFF (VOUT - VIN + VF )
(INEQUALITY 1)
Use this equation to calculate the maximum output current when the LT3464 is operating in continuous mode. IOUT (CM) = (2LILIM + tOFF (VIN - VOUT - VF ))(VIN - VCESAT ) 2L(VOUT - VCESAT + VF ) (2)
Use this equation to calculate the maximum output current when the LT3464 is operating in discontinuous mode.
IOUT (DCM) = LILIM (VIN - VCESAT ) (3) 2(LILIM + VIN tOFF - tOFF VCESAT )(- VIN + VOUT + VF )
2
Where VF is the Schottky forward voltage, ILIM is the switch current limit, tOFF is the switch off time, and VCESAT is the switch saturation voltage. See the Electrical Specifications. Figures 1 through 3 show the worst-case maximum output current as given by Equations 2 and 3 using 20% inductor derating and worst-case LT3464 specifications. Also note that for some applications the maximum output current is limited to 25mA by the output disconnect circuitry.
25
20 L = 47H
L = 22H
15 L = 22H 10 L = 10H
L = 10H
5 L = 4.7H 0
5 L = 4.7H 0
10
15
20
25 VOUT (V)
30
35
3464 F02
15
20
25 VOUT (V)
30
35
3464 F03
Figure 3. Maximum Output Current VIN = 8.4V
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LT3464
APPLICATIO S I FOR ATIO
Capacitor Selection The small size and low ESR of ceramic capacitors makes them suitable for LT3464 applications. X5R and X7R types are recommended because they retain their capacitance over wider voltage and temperature ranges than other types such as Y5V or Z5U. A 1F input capacitor and a 0.22F to 0.47F output capacitor are sufficient for most LT3464 applications. Always use a capacitor with a sufficient voltage rating. Table 2 shows a list of several capacitor manufacturers. Consult the manufacturers for more detailed information and for their entire selection of related parts.
Table 2. Recommended Ceramic Capacitor Manufacturers
MANUFACTURER Taiyo Yuden AVX Murata Kemet PHONE 408-573-4150 843-448-9411 814-237-1431 408-986-0424 URL www.t-yuden.com www.avxcorp.com www.murata.com www.kemet.com
Output Voltage Ripple Using low ESR capacitors will help minimize the output ripple voltage, but proper selection of the inductor and the output capacitor also plays a big role. The LT3464 provides energy to the load in bursts by ramping up the inductor current, then delivering that current to the load. If too large an inductor value or too small a capacitor value is used, the output ripple voltage will increase because the capacitor will be slightly overcharged each burst cycle. To reduce this effect, a larger output capacitor may be used. The LT3464 also includes an on-chip phase-lead capacitor between the CAP pin and the FB pin to greatly reduce ripple; however, certain applications can benefit from additional capacitance in parallel with the integrated capacitor, which may be added externally between the CAP and FB pins. Typical effective values range from 4.7pF to 20pF. Since the FB pin sits at a low voltage, be sure the chosen capacitor has a sufficient voltage rating. Setting Output Voltage and the Auxiliary Reference Input The LT3464 is equipped with both an internal 1.25V reference and an auxiliary reference input. This allows the
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user to select between using the built-in reference, and supplying an external reference voltage. The voltage at the CTRL pin can be adjusted while the chip is operating to alter the output voltage of the LT3464 for purposes such as display dimming or contrast adjustment. To use the internal 1.25V reference, the CTRL pin must be held higher than 1.5V, which can be done by tying it to VIN. When the CTRL pin is held between 0V and 1.2V the LT3464 will regulate the output such that the FB pin voltage is equal to the CTRL pin voltage. To set the output voltage, select the values of R1 and R2 according to the following equation (see Figure 4).
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V R2 = R1 OUT - 1 VREF
Where VREF =1.25V if the internal reference is used, or VREF = VCTRL if VCTRL is between 0V and 1.2V. Choosing a Feedback Node The top of the feedback divider may be connected to the OUT pin or to the CAP pin (see Figure 4). Regulating the OUT pin eliminates the output offset resulting from the voltage drop across the output disconnect. However, in the case of a short-circuit fault at the OUT pin, the LT3464 will switch continuously because the FB pin is low. While operating in this open-loop condition, the rising voltage at the CAP pin is limited only by the current limit of the output disconnect. Given worst-case parameters this voltage may reach 25V. When the short-circuit is removed, the OUT pin will bounce up to the voltage on the CAP pin, potentially exceeding the set output voltage until the capacitor voltages fall back into regulation. While this is harmless to the LT3464, this should be considered in the context of the external circuitry if short-circuit events are expected. Regulating the CAP pin ensures that the voltage on the OUT pin never exceeds the set output voltage after a shortcircuit event. However, this setup does not compensate for the voltage drop across the output disconnect, resulting in an output voltage that is slightly lower than the voltage set by the resistor divider. The next section discusses how to compensate for this drop.
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LT3464
APPLICATIO S I FOR ATIO
7 VIN 1 6 SW OUT CTRL LT3464 CAP 8 SHDN FB GND 4 2 R1 GND 4 5 R2 8 3 VOUT 1 CTRL LT3464 CAP SHDN FB 2 5 7 VIN 6 SW OUT
VOUT
VCAP-OUT (SAT)
3
Figure 4. Feedback Connection Using the CAP Pin and the OUT Pin
Output Disconnect Considerations The LT3464 is equipped with an output disconnect that isolates the load from the input during shutdown. See the Operation section for a functional diagram. The output disconnect uses a pass PNP coupled with circuitry that varies the base current such that the transistor is consistently at the edge of saturation, thus yielding the best compromise between VCE(SAT) and low quiescent current. To remain stable, this circuit requires a bypass capacitor connected between the OUT pin and the CAP pin or between the OUT pin and ground. A ceramic capacitor with a value of at least 0.1F is a good choice. The PNP VCE(SAT) varies with load current as shown in Figure 5. This voltage drop (VDROP) can be accounted for when using the CAP pin as the feedback node by setting the output voltage according to the following formula:
V + VDROP R2 = R1 OUT - 1 VREF
In addition, the disconnect circuit has a built in current limit of 25mA (minimum) to protect the chip during shortcircuit. This feature allows the LT3464 to tolerate an
10
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300 250 200 150 100 50 0
3464 F01
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R2
R1
0
5
10 15 20 25 COLLECTOR CURRENT (mA)
30
3464 F02
Figure 5: Output Disconnect Voltage Drop (VDROP) vs Current
indefinite short, but care must be taken to avoid exceeding the maximum junction temperature. Inrush Current When VIN is stepped from ground to operating voltage while the output capacitor is discharged, an inrush current will flow through the inductor and integrated Schottky diode into the output capacitor. Conditions that increase inrush current include a larger more abrupt voltage step at VIN, a larger output capacitor tied to the CAP pin, and an inductor with a low saturation current. While the internal diode is designed to handle such events, the inrush current should not be allowed to exceed 1 amp. For circuits that use output capacitor values within the recommended range and have input voltages of less than 5V, inrush current remains low, posing no hazard to the device. In cases where there are large steps at VIN (more than 5V) and/or a large capacitor is used at the CAP pin, inrush current should be measured to ensure safe operation.
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LT3464
APPLICATIO S I FOR ATIO
Board Layout Considerations As with all switching regulators, careful attention must be paid to the PCB board layout and component placement. To maximize efficiency, switch rise and fall times are made as short as possible. To prevent electromagnetic interference (EMI) problems, proper layout of the high frequency switching path is essential. The voltage signal of the SW
VOUT
Figure 6. Recommended Layout
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pin has sharp rising and falling edges. Minimize the length and area of all traces connected to the SW pin and always use a ground plane under the switching regulator to minimize interplane coupling. In addition, the ground connection for the feedback resistor R1 should be tied directly to the GND pin and not shared with any other component, ensuring a clean, noise-free connection. Recommended component placement is shown in Figure 6.
GND VIN GND VIAS TO GROUND PLANE VIA TO CONTROL VIA TO SHDN
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LT3464
TYPICAL APPLICATIO S
15V Output Converter with Output Disconnect
VIN 2.3V TO 10V 7 VIN 1 L1 22H 6 SW OUT C1 1F CTRL LT3464 8 SHDN FB GND 4
3464 TA02
C1: TAIYO YUDEN LMK107 BJ105MA-T C2: TAIYO YUDEN EMK107 BJ224MA-T C3: TAIYO YUDEN EMK107 BJ224MA-T L1: MURATA LQH32CN220K
VIN 2.3V TO 10V 7 VIN 1
C1 1F
8
C1: TAIYO YUDEN LMK107 BJ105MA-T C2: TAIYO YUDEN GMK212 BJ334MG-T C3: TAIYO YUDEN UMK212 BJ224MG-T L1: MURATA LQH32CN470K
20V Output Converter with Output Disconnect Using an 0805 Inductor and 0603 Capacitors
VIN 2.3V TO 10V 7 VIN 1 L1 10H 6 SW OUT C1 1F CTRL LT3464 8 SHDN FB GND 4
3464 TA04
C1: TAIYO YUDEN LMK107 BJ105MA-T C2: TAIYO YUDEN TMK107 BJ104MA-T C3: TAIYO YUDEN TMK107 BJ104MA-T L1: TAIYO YUDEN LB 2012T100MR
12
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3 C3 0.22F C2 0.22F 2
VOUT 15V
CAP
5
VIN (V)
R2 3.32M R1 301k
IOUT (mA) 7.0 10.0 19.0
3.6 5.0 8.4
34V Output Converter with Output Disconnect
L1 47H 6 SW OUT CTRL LT3464 SHDN FB GND 4
3464 TA03
3 C3 0.22F C2 0.33F 2
VOUT 34V
CAP
5
VIN (V)
R2 2.61M R1 100k
IOUT (mA) 3.5 4.5 7.5
3.6 5.0 8.4
3 C3 0.1F C2 0.1F 2
VOUT 20V
CAP
5
VIN (V)
R2 4.53M R1 301k
IOUT (mA) 3.0 4.0 6.0
3.6 5.0 8.4
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LT3464
TYPICAL APPLICATIO S
20V Output Converter with Output Disconnect
L1 47H 7 VIN 1 6 SW OUT C1 1F CTRL LT3464 8 SHDN FB GND 4
3464 TA05
VIN 2.3V TO 10V
C1: TAIYO YUDEN LMK107 BJ105MA-T C2: TAIYO YUDEN GMK212 BJ334MG-T C3: TAIYO YUDEN UMK212 BJ224MG L1: MURATA LQH32CN470K
VIN 2.3V TO 10V OFF ON 7 VIN 8 R1 300k
C4 1F
1
C4 0.1F
C1: TAIYO YUDEN LMK107 BJ105MA-T C2: TAIYO YUDEN GMK212 BJ334MG-T C3: TAIYO YUDEN EMK107 BJ224MA-T L1: MURATA LQH32CN220K
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3 C3 0.22F C2 0.33F 2
VOUT 20V
CAP
5
VIN (V)
R2 4.53M R1 301k
IOUT (mA) 6.0 9.0 16.5
3.6 5.0 8.4
20V Output Converter with Soft Start
L1 22H 6 SW OUT SHDN LT3464 CTRL FB GND 4
3464 TA06
3 C3 0.22F C2 0.33F 2
VOUT 20V
CAP
5
VIN (V)
R2 4.53M R1 301k
IOUT (mA) 5.0 6.5 11.0
3.6 5.0 8.4
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LT3464
TYPICAL APPLICATIO S
8V Output Converter with Output Disconnect
L1 22H 7 VIN 8 6 SW OUT C4 1F SHDN LT3464 1 CTRL FB GND 4
3464 TA07
VIN 2.3V TO 7V
C1: TAIYO YUDEN CE LMK107 BJ105MA-T C2: TAIYO YUDEN CE LMK212 BJ225MG-T C3: TAIYO YUDEN CE LMK107 BJ474MA-T L1: MURATA LQH32CN220K
VIN 2.3V TO 10V 7 VIN 1
C1 1F
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3 C3 0.47F C2 2.2F C4 20pF
VOUT 8V
CAP
5
VIN (V)
R2 1.62M R1 301k
IOUT (mA) 13.5 20
3.6 5.0
2
20V Dual Output Converter with Output Disconnect
-VOUT I = 2.5mA AT VIN = 3.6V -20V OUT C4 0.33F
L1 47H 6 SW OUT CTRL LT3464 8 SHDN FB GND 4 CAP
C5 D1 0.33F
D2
3 C3 0.22F C2 0.33F 2
VOUT 20V
IOUT = 2.5mA AT VIN = 3.6V
5
R2 4.53M R1 301k
3464 TA08
C1: TAIYO YUDEN LMK107 BJ105MA-T C2, C4, C5: TAIYO YUDEN GMK212 BJ334MG-T C3: TAIYO YUDEN UMK212 BJ224MG-T L1: MURATA LQH32CN470K D1, D2: CENTRAL CMDSH-3
3464f
LT3464
PACKAGE DESCRIPTIO U
TS8 Package 8-Lead Plastic TSOT-23
(Reference LTC DWG # 05-08-1637)
0.65 REF 2.90 BSC (NOTE 4) 1.22 REF 1.4 MIN 2.80 BSC 1.50 - 1.75 (NOTE 4) PIN ONE ID 0.65 BSC 0.22 - 0.36 8 PLCS (NOTE 3) 0.80 - 0.90 0.20 BSC 1.00 MAX DATUM `A' 0.01 - 0.10 0.09 - 0.20 (NOTE 3) 1.95 BSC
TS8 TSOT-23 0802
0.52 MAX
3.85 MAX 2.62 REF
RECOMMENDED SOLDER PAD LAYOUT PER IPC CALCULATOR
0.30 - 0.50 REF NOTE: 1. DIMENSIONS ARE IN MILLIMETERS 2. DRAWING NOT TO SCALE 3. DIMENSIONS ARE INCLUSIVE OF PLATING 4. DIMENSIONS ARE EXCLUSIVE OF MOLD FLASH AND METAL BURR 5. MOLD FLASH SHALL NOT EXCEED 0.254mm 6. JEDEC PACKAGE REFERENCE IS MO-193
3464f
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.
15
LT3464
TYPICAL APPLICATIO S
20V Output Converter with Variable Output Voltage and Shutdown
VIN 2.3V TO 10V L1 22H C1 1F 7 VIN 1 6 SW OUT DAC CTRL LT3464 C 8 SHDN FB GND 4
3464 TA09
RELATED PARTS
PART NUMBER LT1613 LT1615/ LT1615-1 LT1618 LT1932 LT1937 LT1944 LT1944-1 LT1945 LTC3200/ LTC3200-5 LTC3201 LTC3202 LTC3400/ LTC3400B LTC3401 LTC3402 DESCRIPTION 550mA (ISW), 1.4MHz, High Efficiency Step-Up DC/DC Converter 300mA/80mA (ISW), Constant Off-Time, High Efficiency Step-Up DC/DC Converter Constant Current, Constant Voltage, 1.4MHz, High Efficiency Boost Regulator Constant Current, 1.2MHz, High Efficiency White LED Boost Regulator Constant Current, 1.2MHz, High Efficiency White LED Boost Regulator Dual Output 350mA (ISW), Constant Off-Time, High Efficiency Step-Up DC/DC Converter Dual Output 150mA (ISW), Constant Off-Time, High Efficiency Step-Up DC/DC Converter Dual Output, 350mA (ISW), Constant Off-Time, High Efficiency Step-Up DC/DC Converter Low Noise, 2MHz, Regulated Charge Pump White LED Driver Low Noise, 1.7MHz, Regulated Charge Pump White LED Driver Low Noise, 1.5MHz, Regulated Charge Pump White LED Driver 600mA (ISW), 1.2MHz, Synchronous Step-Up DC/DC Converter 1A (ISW), 3MHz, Synchronous Step-Up DC/DC Converter 2A (ISW), 3MHz, Synchronous Step-Up DC/DC Converter COMMENTS VIN = 0.9V to 10V, VOUT(MAX) = 34V, IQ = 3mA, ISD = <1A, ThinSOT Package VIN = 1.2V to 15V, VOUT(MAX) = 34V, IQ = 20A, ISD = <1A, ThinSOT Package VIN = 1.6V to 18V, VOUT(MAX) = 34V, IQ = 1.8mA, ISD = <1A, MS Package, Up to 6 White LEDs VIN = 1V to 10V, VOUT(MAX) = 34V, IQ = 1.2mA, ISD = <1A, ThinSOT Package, Up to 8 White LEDs VIN = 2.5V to 10V, VOUT(MAX) = 34V, IQ = 1.9mA, ISD = <1A, SC-70, ThinSOT Packages, Up to 4 White LEDs VIN = 1.2V to 15V, VOUT(MAX) = 34V, IQ = 20A, ISD = <1A, MS Package VIN = 1.2V to 15V, VOUT(MAX) = 34V, IQ = 20A, ISD = <1A, MS Package VIN = 1.2V to 15V, VOUT(MAX) = 34V, IQ = 20A, ISD = <1A, MS Package VIN = 2.7V to 4.5V, IQ = 8mA, ISD = <1A, MS, ThinSOT Packages, Up to 6 White LEDs VIN = 2.7V to 4.5V, IQ = 6.5mA, ISD = <1A, MS Package, Up to 6 White LEDs VIN = 2.7V to 4.5V, IQ = 5mA, ISD = <1A, MS Package, Up to 8 White LEDs VIN = 0.85V to 5V, VOUT(MAX) = 5V, IQ = 19A/300A, ISD = <1A, ThinSOT Package VIN = 0.5V to 5V, VOUT(MAX) = 6V, IQ = 38A, ISD = <1A, MS Package VIN = 0.5V to 5V, VOUT(MAX) = 6V, IQ = 38A, ISD = <1A, MS Package
3464f LT/TP 0204 1K * PRINTED IN USA
16
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900 q FAX: (408) 434-0507
q
U
3 C3 0.22F C2 0.33F 2
VOUT 20V
CAP
5
VIN (V)
R2 4.53M R1 301k
IOUT (mA) 5.0 6.5 11.0
3.6 5.0 8.4
C1: TAIYO YUDEN LMK107 BJ105MA-T C2: TAIYO YUDEN GMK212 BJ334MG-T C3: TAIYO YUDEN GMK212 BJ224MG-T L1: MURATA LQH32CN220K
www.linear.com
(c) LINEAR TECHNOLOGY CORPORATION 2003

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