Buck Controller Touts Unique Features

Targeting modular and on-the-board supplies, the TPS40100 synchronous dc/dc buck controller employs innovative sequencing and output voltage margining features. It supports three sequencing schemes: sequential, ratio-metric, and simultaneous sequencing. A power good function initiates sequential sequencing, where a single supply output voltage ramps up and settles at its final regulation voltage before the next supply ramps up. Via a soft-start capacitor, the controller implements a ratio-metric scheme, which raises both outputs simultaneously until regulation occurs. Additionally, simultaneous sequencing is activated via an internal amplifier. The device also employs a margining-control function that allows temporary adjustment of output voltages to a value above or below nominal regulation. Two digital input pins provide up or down margining by ±5% or ±3%. General specs include a 4.5V to 18V input, adjustable frequency range from 100 kHz to 600 kHz, 0.7V reference, peak-current-mode control, and efficiencies up to 90%. Available in a 24-pin QFN package, price is $1.45 each/1,000. TEXAS INSTRUMENTS INC., Dallas, TX. (800) 477-8924.