Update: 30 September, 2023
LX1681/1682 are monolithic pulse-width modulator controller ICs, designed to implement a flexible, low cost buck (step-down) regulator supply with minimum external components. The LX1681 is a non-synchronous controller; the LX1682 has a synchronous driver for higher efficiency. The output voltage is adjustable by means of a resistor divider to set the voltage between 1.25V and 4.5V. Short-circuit current limiting can be implemented without expensive current sense resistors. Current is sensed using the voltage drop across the RDS(ON) of the MOSFET — sensing is delayed for 1µs to eliminate MOSFET ringing errors. Hiccup-mode fault protection reduces average power to the power elements during short-circuit conditions. Switching frequency is fixed at 200kHz for optimal cost and space. Under-voltage lockout and soft-start for optimal start-up performance. The LX1681/82 can be disabled by pulling the soft-start pin to ground. Small 8-pin SOIC packaging reduces board space. Optimized for 5V-to-3.3V or 5V-to-2.5V conversion, the LX1681/82 can also be used for other voltage conversions.
File format: PDF
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MD5 Checksum: 631F9E30FB37512AF067CEB357C13220
Publication date: 07 June, 2012
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PDF Link: LINFINITY LX1681/1682 DATA SHEET PDF