LTC3862-1 LINER [Linear Technology], LTC3862-1 Datasheet
LTC3862-1
Related parts for LTC3862-1
LTC3862-1 Summary of contents
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... RUN pin threshold with programmable hyster- esis, soft-start and programmable leading edge blanking and maximum duty cycle. The LTC3862 gate drive version of the LTC3862-1. L, LT, LTC and LTM are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. Protected by U.S. Patents, including 6144194, 6498466, 6611131 ...
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... FB Voltage .................................................. –0.3V to 3V8 FREQ Voltage ............................................ –0.3V to 1.5V Operating Junction Temperature Range (Notes 3, 4) LTC3862-1E ......................................... –40°C to 85°C LTC3862-1I ........................................ –40°C to 125°C LTC3862-1H ....................................... –40°C to 150°C Storage Temperature Range ................... –65°C to 150°C Refl ow Peak Body Temperature ........................... 260°C TOP VIEW 1 ...
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... Rising ITH Voltage (Note 6) Hysteresis V = Float, Low Duty Cycle SLOPE (Note Float, Low Duty Cycle (Note 3) SLOPE (V – SENSE1 SENSE2 LTC3862-1 TEMPERATURE RANGE –40°C to 85°C –40°C to 125°C –40°C to 150°C MIN TYP MAX UNITS l 8 ...
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... LTC3862-1 ELECTRICAL CHARACTERISTICS operating temperature range, otherwise specifi cations are at T SYMBOL PARAMETER RUN/Soft-Start I RUN Source Current RUN V High Level RUN Channel Enable Threshold RUN V RUN Threshold Hysteresis RUNHYS I SS Pull-Up Current Pull-Down Resistance SS Oscillator f Oscillator Frequency OSC Oscillator Frequency Range ...
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... LOAD Shutdown Quiescent Current vs Input Voltage 150 INPUT VOLTAGE (V) LTC3862-1 5000 = 72V = 0.5A 4500 4000 3500 EFFICIENCY 3000 2500 POWER LOSS 2000 1500 INPUT VOLTAGE (V) 38621 G02 Quiescent Current vs Input Voltage 5.6 5 ...
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... LTC3862-1 TYPICAL PERFORMANCE CHARACTERISTICS INTV Line Regulation CC 10.2 10.1 10.0 9.9 9 INPUT VOLTAGE (V) 38621 G09 INTV LDO Dropout CC vs Load Current, Temperature 1200 1000 150°C 125°C 800 85°C 600 25°C 400 –40°C 200 INTV LOAD (mA) ...
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... TEMPERATURE (°C) Soft-Start Current vs Soft-Start Voltage 0 –1 –2 –3 –4 –5 –6 150 0 0.5 1 1.5 2 2.5 3 SOFT-START VOLTAGE (V) LTC3862-1 RUN Threshold vs Input Voltage 1.5 1.4 1.3 ON 1.2 OFF 1.1 1 INPUT VOLTAGE (V) 38612 G19 RUN Source Current vs Input Voltage 0 –1 –2 –3 – ...
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... LTC3862-1 TYPICAL PERFORMANCE CHARACTERISTICS Oscillator Frequency vs Input Voltage 320 315 310 305 300 295 290 285 280 INPUT VOLTAGE (V) 38621 G27 Frequency Pin Voltage vs Temperature 1.235 1.233 1.231 1.229 1.227 1.225 1.223 1.221 1.219 1.217 1.215 1.213 1.211 – ...
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... V output voltage. FREQ: A resistor from FREQ to SGND sets the operating frequency. GATE1, GATE2: Gate Drive Output. The LTC3862-1 pro- vides a 10V gate drive referenced to PGND to drive a high voltage MOSFET. INTV : Output of the Internal 10V Low Dropout Regulator CC (LDO). A low ESR 4.7μ ...
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... LTC3862-1 PIN FUNCTIONS + + SENSE1 , SENSE2 : Positive Inputs to the Current Comparators. The ITH pin voltage programs the current comparator offset in order to set the peak current trip threshold. This pin is normally connected to a sense resistor in the source of the power MOSFET. – – SENSE1 ...
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... MAX BLOGIC PWM LATCH + OV ITRIP R ICMP LOOP PSKIP – RUN EA – – 4.5μA + – 1.223V 1.345V 1.22V LTC3862 10V LDO INTV CC C VCC 3.8V LDO L 3V8 C 3V8 BIAS D GATE + M LOGIC C OUT PGND SENSE – ...
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... MOSFETs from operating with inadequate gate drive. For the LTC3862-1 the rising UVLO threshold is typically 7.5V and the hys- teresis is typically 500mV. The LTC3862-1 was optimized for high voltage power MOSFETs and applications. For applications requiring logic-level power MOSFETs, please refer to the LTC3862 data sheet ...
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... IC pins. This LDO is not intended to be used as a supply for external circuitry. Thermal Considerations and Package Options The LTC3862-1 is offered in three package options. The 5mm × 5mm QFN package (UH24) has a thermal resistance R of 34°C/W, the 24-pin TSSOP (FE24) package has a TH(JA) thermal resistance of 38° ...
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... Operation at Low Supply Voltage The LTC3862-1 has a minimum input voltage of 8.5V, making it a good choice for applications that require high voltage power MOSFETs. The gate driver for the LTC3862-1 consists ...
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... IC. If, however, the V INTV supply, the external INTV CC load to the internal LDO in the LTC3862-1, and the LDO will attempt to charge the INTV current. This will result in excessive power dissipation and possible thermal overload of the LTC3862-1. Programming the Output Voltage ...
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... LTC3862-1 OPERATION Operation of the RUN Pin The control circuitry in the LTC3862-1 is turned on and off using the RUN pin. Pulling the RUN pin below 1.22V forces shutdown mode and releasing it allows a 0.5μA current source to pull this pin up, allowing a “normally on” converter to be designed. Alternatively, the RUN pin can be externally pulled up or driven directly by logic ...
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... R = 5.5096E9(f ) FREQ OSC A phase-lock loop is available on the LTC3862-1 to syn- chronize the internal oscillator to an external clock source connected to the SYNC pin. Connect a series RC network from the PLLFLTR pin to SGND to compensate PLL’s feedback loop. Typical compensation components are a 0.01μF capacitor in series with a 10k resistor. The PLLFLTR pin is both the output of the phase detector and the input to the voltage controlled oscillator (VCO) ...
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... Using the LTC3862-1 Transconductance (g Amplifi Multi-Phase Applications The LTC3862-1 error amplifi transconductance amplifi er, meaning that it has high DC gain but high output impedance (the output of the error amplifi current proportional to the differential input voltage). This style of error amplifi ...
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... OPERATION LTC3862-1 chip, connect all of the SS pins together and use one external capacitor to program the soft-start time. In this case, the current into the soft-start capacitor will • 5μA, where n is the number of SS pins connected SS together. Figure 9 illustrates the start-up waveforms for a 2-phase LTC3862-1 application ...
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... Figure 12. Effect of Slope Gain on the Peak SENSE Threshold 20 Programmable Blanking and the Minimum On-Time The BLANK pin on the LTC3862-1 allows the user to pro- gram the amount of leading edge blanking at the SENSE pins. Connecting the BLANK pin to SGND results in a minimum on-time of 210ns, fl oating the pin increases this time to 290ns, and connecting the BLANK pin to the 3V8 supply results in a minimum on-time of 375ns ...
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... Figure 13. Leading Edge Blanking Effects on the Minimum On-Time In order to satisfy these different applications require- ments, the LTC3862-1 has a simple way to program the maximum duty cycle. Connecting the D limits the maximum duty cycle to 96%. Floating this pin limits the duty cycle to 84% and connecting the D to the 3V8 supply limits it to 75% ...
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... SENSE and SENSE be less than 1μA. Since the LTC3862-1 contains leading edge blanking, an external RC fi lter is not required for proper operation. However external fi lter is used, the fi lter components should be placed close to the SENSE the IC, as shown in Figure 15. The positive and negative ...
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... Figure 17 illustrates the load step response of a properly compensated boost converter. I LOAD 1A/DIV I L1 2A/DIV I L2 2A/DIV V OUT 1V/DIV 400μs/DIV V = 24V 72V OUT Figure 17: Load Step Response of a Properly Compensated Boost Converter LTC3862-1 and the bandwidth decreased, the C 38621 F17 . 38621f 23 ...
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... O F For a given input voltage range and output voltage important to know how close the minimum on-time of the application comes to the minimum on-time of the control IC. The LTC3862-1 minimum on-time can be programmed from 210ns to 375ns using the BLANK pin. D MAX SLOPE BLANK PHASEMODE 66 ...
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... Peak and Average Input Currents The control circuit in the LTC3862-1 measures the input current (by means of resistors in the sources of the power MOSFETs), so the output current needs to be refl ected back to the input in order to dimension the power MOSFETs properly ...
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... I , and thermal resistances R D(MAX) junction-to-ambient and junction-to-case. The gate driver for the LTC3862-1 consists of PMOS pull- ) O(CL) up and NMOS pull-down devices, allowing the full INTV voltage to be applied to the gates during power MOSFET switching. Nonetheless, care must be taken to ensure that the minimum gate drive voltage is still suffi ...
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... MOSFETs. DS(ON) Programming the Current Limit The peak sense voltage threshold for the LTC3862-1 is 75mV at low duty cycle and with a normalized slope gain of 1.00, and is measured from SENSE illustrates the change in the sense threshold with varying duty cycle and slope gain ...
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... LTC3862-1 APPLICATIONS INFORMATION For a boost converter where the current limit value is chosen to be 30% higher than the maximum load current, the peak current in the MOSFET and sense resistor is • 1+ SW(MAX) R(SENSE The sense resistor value is then • n • 1– D ...
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... SW1 SW2 I L1 2A/DIV I L2 2A/DIV V OUT 1μs/DIV V = 24V 72V OUT 350mA LOAD Figure 22. Switching Waveforms for a Boost Converter LTC3862-1 0.01• V OUT ≤ I D(PEAK O(MAX) = • 1+ • 1– D MAX 38621 F22 38621f 29 ...
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... LTC3862-1 APPLICATIONS INFORMATION For the bulk capacitance, which we assume contributes 1% to the total output ripple, the minimum required ca- pacitance is approximately: I O(MAX) C ≥ OUT 0.01• n • V • f OUT For many designs it will be necessary to use one type of capacitor to obtain the required ESR, and another type to satisfy the bulk capacitance ...
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... DUTY CYCLE Figure 24. Normalized Input Peak-to-Peak Ripple Current A Design Example Consider the LTC3862-1 application circuit is shown in Figure 25a. The output voltage is 72V and the input voltage range is 8.5V to 36V. The maximum output current is 1.5A when the input voltage is 24V and input of 32V. ...
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... LTC3862-1 APPLICATIONS INFORMATION D MAX SLOPE BLANK PHASEMODE 45.3k FREQ 0.1μF SS LTC3862-1 1.5nF 45.3k ITH 100pF FB 5.62k SGND 324k V OUT CLKOUT SYNC PLLFLTR Figure 25a. A 8.5V to 36V Input, 72V/2A Output 2-Phase Boost Converter Application Circuit 2.5 2.0 1.5 1.0 0 INPUT VOLTAGE (V) Figure 25b. Output Current vs Input Voltage 4 ...
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... The maximum current sense threshold for the LTC3862-1 is 75mV at low duty cycle and a normalized slope gain of 1.0. Using Figure 20, the maximum sense voltage drops to 68mV at a duty cycle of 70% with a normalized slope gain the sense resistor is calculated to be: ...
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... F26 7. Place the small-signal components away from high frequency switching nodes on the board. The pinout of the LTC3862-1 was carefully designed in order to make component placement easy. All of the power components can be placed on one side of the IC, away from all of the small-signal components. ...
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... MOSFET. If this ringing cannot be avoided and exceeds the maximum rating of the device, choose a higher voltage rated MOSFET or consider using a snubber. 16. When synchronizing the LTC3862 external clock, use a low impedance source such as a logic gate to drive the SYNC pin and keep the lead as short as possible. ...
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... LTC3862-1 TYPICAL APPLICATION A 24V Input, 48V/6A Output 2-Phase Boost Converter Application Circuit D MAX SLOPE BLANK PHASEMODE 45.3k FREQ 0.1μF SS 4.7nF LTC3862-1 30.1k ITH 100pF FB 7.87k SGND 301k V OUT CLKOUT SYNC PLLFLTR Start-Up RUN 5V/DIV I L1 5A/DIV I L2 5A/DIV V OUT 50V/DIV 1ms/DIV V = 24V 48V ...
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... LOAD Effi ciency 100 V = 24V 107V OUT 96 EFFICIENCY 92 88 POWER LOSS 100 1000 10000 LOAD CURRENT (mA) 38621 TA03d LTC3862-1 D1 PDS4150 Q1 Si7430DP 0.010Ω 1W 100μF 150V V + OUT 107V 1.5A (MAX) 8× 1μF 250V 0.010Ω Si743ODP D2 PDS4150 3862 TA03a ...
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... LTC3862-1 PACKAGE DESCRIPTION 6.60 0.10 4.50 0.10 RECOMMENDED SOLDER PAD LAYOUT 0.09 – 0.20 (.0035 – .0079) NOTE: 1. CONTROLLING DIMENSION: MILLIMETERS 2. DIMENSIONS ARE IN 3. DRAWING NOT TO SCALE .254 MIN .0165 .0015 RECOMMENDED SOLDER PAD LAYOUT .0075 – .0098 (0.19 – 0.25) .016 – .050 (0.406 – 1.270) NOTE: 1. CONTROLLING DIMENSION: INCHES 2 ...
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... UH Package 24-Lead Plastic QFN (5mm × 5mm) (Reference LTC DWG # 05-08-1747 Rev Ø) 0.75 ±0.05 PACKAGE OUTLINE 0.30 ± 0.05 0.65 BSC R = 0.05 0.75 ± 0.05 0.00 – 0.05 3.25 REF 0.200 REF LTC3862-1 PIN 1 NOTCH R = 0.30 TYP BOTTOM VIEW—EXPOSED PAD OR 0.35 × 45° TYP CHAMFER R = 0.115 TYP 23 24 0.55 ± 0. 3.20 ± ...
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... Current Mode Synchronous Step-Up Controller LT3825 Isolated No-OPTO Synchronous Flyback Controller with Wide Input Supply Range LT3837 Isolated No-OPTO Synchronous Flyback Controller LTC3862 Multi-Phase Current Mode Step-Up DC/DC Controller 5V Gate Drive Version of LTC3862-1 LTC3872 No R Current Mode Boost DC/DC Controller SENSE LTC3873 No R ...