LT1573 is a low cost, high current, low dropout, fast transient response regulator driver IC that can be used with an external PNP power transistor to provide up to 5A of current with a dropout voltage as low as 0.35V. The device is designed for extremely fast transient response. This greatly reduces bulk storage capacitance when the regulator is used in applications with fast, high current load transients. To keep cost and complexity low, the LT1573 uses a new time-delayed latching overcurrent protection technique that requires no external current sense resistor. Base drive is limited for instantaneous protection, and a time-delayed latch protects the regulator from continuous short circuits. The LT1573 is available in both adjustable and fixed versions with a operating voltage range of 2.8V to 10V.
The LT1573 is a low‑cost, high‑current regulator driver IC that works with an external PNP power transistor to deliver up to 5 A load current with very low dropout voltage (<0.2 V). It features fast transient response, time‑delayed latching overcurrent protection, and a shutdown pin for easy power control.
The document provides absolute maximum ratings, detailed electrical characteristics, pin descriptions, typical performance curves, application circuit examples, and package dimensions for the 8‑lead plastic small‑outline package.
| Output voltage range (adjustable) | 1.27 V to 6.8 V |
|---|---|
| Fixed output voltages | 2.5 V, 2.8 V, 3.3 V |
| Maximum load current | 5 A |
| Dropout voltage | < 0.2 V |
| Shutdown pin threshold voltage | 1.0 V to 1.33 V |
| Package type | 8‑Lead Plastic Small Outline (narrow 0.150) |
The LT1573 can deliver up to 5 A of load current when used with an external PNP transistor.
The device is capable of a very low dropout voltage of less than 0.2 V.
It uses a time‑delayed latching overcurrent protection circuit that disables the output after a latch‑off timeout if the fault persists.