600-mA Negative LDO Features Rail-To-Rail Operation, Programmable Current Limit

A low-dropout negative linear regulator developed by Linear Technology, equipped with a 600-mA output current, offers low noise, rail-to-rail operation, precision programmable current limit, and a bidirectional output-current monitor. The cable-drop compensation-capable LT3090 can be easily paralleled for higher current or printed-circuit-board (PCB) heat spreading, or configured as a floating three-terminal regulator. Input voltage ranges from −1.5 to −36 V. A single resistor programs the adjustable rail-to-rail output voltage from 0 to −32 V; dropout voltage is 300 mV (typical at full load). The regulator includes a trimmed, ±1% accurate, 50-µA current-source reference. It provides ±2% output-voltage tolerance over line, load, and temperature. Output-voltage regulation, bandwidth, transient response, and output noise (18 µV rms over 10 Hz to 100 kHz) remain independent of output voltage thanks to a unity-gain voltage follower architecture. The LT3090 is stable with a minimum of 4.7-µF output capacitor. A bipolar current monitor either sources or sinks a current proportional to output current. Also, a bidirectional shutdown capability allows the device to operate with either positive or negative logic levels.

LINEAR TECHNOLOGY CORP.