LTC3901 Linear Technology, LTC3901 Datasheet
LTC3901
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LTC3901 Summary of contents
Page 1
... L The LTC3901 provides a full range of protection features for the external MOSFETs. A programmable timeout func- tion is included that disables both drivers when the syn- chronization signal is missing or incorrect. Additionally, the chip senses the output inductor current through the drain-source resistance of the two MOSFETs, turning off the MOSFETs if the inductor current reverses ...
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... Driver Off IN V – (Note ±10V SYNC (Note 7) (Note –100mA OUT I = 100mA OUT (Note ORDER PART NUMBER LTC3901EGN PGND – 12 CSF + GN PART 11 CSF 10 MARKING GND 9 SYNC 3901 MIN TYP MAX UNITS ● 4 ● 4.1 4 ...
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... Note 1: Absolute Maximum Ratings are those values beyond which the life of a device may be impaired. Note 2: The LTC3901E is guaranteed to meet performance specifications from 0°C to 70°C. Specifications over the –40°C to 85°C operating temperature range are assured by design; characterization and correlation with statistical process controls. Note 3: All currents into device pins are positive ...
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... LTC3901 W U TYPICAL PERFOR A CE CHARACTERISTICS SYNC Negative Threshold vs Temperature –1 5V, 11V CC –1.1 –1.2 –1.3 –1.4 –1.5 –1.6 –1.7 –1.8 –50 – 100 125 TEMPERATURE (°C) 3901 G07 Propagation Delay vs C LOAD 120 T = 25° 110 CC 100 ...
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... SYNC input. If the SYNC signal is missing or incorrect, the LTC3901 pulls both ME and MF low once the TIMER pin goes above the timeout threshold. See the Timer sec- tion for more details on programming the timeout period. ...
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... T2 is driven by the LTC3723’s SDRA and SDRB outputs and provides the synchronization signal to the LTC3901 on the secondary side. When both SDRA and SDRB are high, there is no voltage across the transformer’s primary and the LTC3901 SYNC input is approximately 0V. ...
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... T1’s secondary and L1. In the second period, SDRA goes high and T2 provides approximately 0V at the LTC3901 SYNC input. This causes the LTC3901’s ME output to go high and both MOSFET ME and MF to conduct. This is the free-wheeling period with T1 secondary winding shorted. In the third period, SDRB goes low (followed by DRVB going high) and T2 generates a negative voltage at the LTC3901’ ...
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... MOSFET causing CSX TMR – CSX by more than 10.5mV, the LTC3901 turns off the discharges. This respective MOSFET. This comparator is used to prevent TMR inductor reverse current buildup during power-down or Burst Mode operation, which may cause damage to the MOSFETs ...
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... R DS(ON) V IN(MAX) voltage the LTC3901 still operates in discontinuous mode with the calculated resistance value, increase the value raise the threshold. The resistors R CSX1 R and the CSX CSX2 trace capacitance forms an R-C delay; this slows down the 0V response time of the comparators. The resistors and CSX input leakage currents also create an input offset error ...
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... REG tions. Figure 10 shows a simplified full-bridge converter circuit. The LTC3901 circuit and operation is the same as in the push-pull application (refer to Figure 1). On the pri- mary side there are four power MOSFETs MD, driven by the respective outputs of the primary controller. Trans- former T3 and T4 step up the gate drives for MA and MC ...
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... The primary side delivers power to the load through MOSFET MF, T1 and L1. In the second period, MA remains on, MD turns off, and MC turns on. E goes high and the LTC3901 forces both ME and MF to conduct. This is the free-wheeling period with the T1 secondary output shorted. ...
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... The power dissipation increases with switch- ing frequency and size of the MOSFETs. To calcu- CC late the driver dissipation, the total gate charge Q This parameter is found on the MOSFET manufacturers’ data sheets. The power dissipated in each LTC3901 MOSFET driver is • PV • f DRIVER G ...
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... U TYPICAL APPLICATIO S LTC3901 3901f 13 ...
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... LTC3901 U TYPICAL APPLICATIO S 14 3901f ...
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... U TYPICAL APPLICATIO S 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 represen- tation that the interconnection of its circuits as described herein will not infringe on existing patent rights. LTC3901 3901f 15 ...
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... Transformer Synchronization Programmable Volt-Second Clamp and Slope Compensation 50W to 2kW Power Supply Design, Adaptive Direct Sense ZVS Adjustable Push-Pull Dead Time, High Efficiency Similar Function to the LTC3901 but for Forward Converter Adjustable Gate Drive Voltage, Programmable Blanking SOT-23, Prevents Overshoot www.linear.com ● ...