Texas Instruments LM2640MTCX-ADJ/NOPB

Description
The LM2640 is a dual step-down power supply controller designed for use in notebook computers and other battery-powered devices. It features fixed-frequency synchronous drive of logic-level N-channel power MOSFETs, combined with an optional pulse-skipping mode for ultra-efficient power conversion over a wide load current range. The pulse-skipping mode can be disabled in favor of fixed-frequency operation regardless of the load current level. High DC gain and current-mode feedback control ensure excellent line and load regulation and a wide loop bandwidth for fast response to dynamic loads. An internal oscillator fixes the switching frequency at 200 kHz, or it can be synchronized to an external clock running as fast as 400 kHz. An optional soft-start feature limits current surges from the input power supply at startup and provides a simple means of start-up sequencing. Logic-level inputs allow the controllers to be turned ON and OFF separately.

Features
200 kHz fixed-frequency switching
Switching synchronization with an external signal up to 400 kHz
Optional pulse-skipping mode
Adjustable secondary feedback
Input undervoltage lockout
Output undervoltage shutdown protection
Output overvoltage shutdown protection
Programmable soft-start (each controller)
5V, 50 mA linear regulator output
Precision 2.5V reference output
28-pin package

Applications
Notebook and subnotebook computers
Wireless data terminals
Battery-powered instruments