ANALOG DEVICES LT3957IUHE#PBF DC-DC Switching Boost/Flyback/Inverting/SEPIC Regulator, Adjustable, 3 to 40V in, 40V out, QFN-EP-36

LT3957IUHE#PBF is a wide input range, current mode DC/DC converter capable of generating positive or negative output voltages. It can be configured as a boost, flyback, SEPIC, or inverting converter. The device features an internal low-side N-channel power MOSFET rated for 40V at 5A, driven from an internally regulated 5.2V supply. Its fixed-frequency, current-mode architecture ensures stable operation over a wide range of supply and output voltages. The operating frequency of the LT3957 can be set with an external resistor across a 100KHz to 1 MHz range and synchronized to an external clock using the SYNC pin. With a minimum operating supply voltage of 3V and low shutdown quiescent current of less than 1?A, the LT3957 is well-suited for battery-powered systems. It also incorporates soft-start and frequency foldback functions to limit inductor current during startup. Applications include automotive, telecom, and industrial uses.

• Wide input voltage range from 3V to 40V, programmable soft-start
• Single feedback pin for positive or negative output voltage
• Current mode control provides excellent transient response, synchronizable to an external clock
• Programmable input undervoltage lockout with hysteresis
• Switching frequency is 100KHz typical at (RT = 140K to SGND, FBX = 1.6V, VC = 1.5V, TA ? TJ = 25°C)
• INTVCC current limit is 40mA typical at (VIN = 40V, TA ? TJ = 25°C)
• Dropout voltage (VIN � VINTVCC) is 450mV typ at (VIN = 5V, IINTVCC = 20mA, VC = 0V, TA ? TJ = 25°C)
• VC source current is -15?A typ at (VC = 1.5V, FBX = 0V, current out of pin, TA ? TJ = 25°C)
• VIN operating IQ is 1.7mA typical at (VC = 0.3V, RT = 41.2K, TA ? TJ = 25°C)
• Operating junction temperature range from -40°C to 125°C, 36-lead plastic QFN package

Notes

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