1 General Description

The RTQ2551A is a very low dropout linear regulator

which operates from input voltage as low as 0.8V. The

device is capable of supplying 1A of output current with

a typical dropout voltage of only 50mV. A VBIAS

supply is required to run the internal reference and

LDO circuitry while output current comes directly from

the VIN supply for high efficiency regulation. Userprogrammable soft-start limits the input inrush current

and minimizes stress on the input power. The enable

input and power good output allow easy sequencing

with external regulators. This complete flexibility

provides an easy-to-use robust power management

solution for a wide variety of applications.

The RTQ2551A is stable with output capacitor greater

than or equal to 2.2F. A precise reference and error

amplifier deliver 2% accuracy over load, line and

temperature. Overcurrent limit and over-temperature

protection are also included. The RTQ2551A is

available in the WDFN-10L 3x3 package.

The recommended junction temperature range is

−40C to 125C

2 Features

⚫ Ultralow VIN Range: 0.8V to 5.5V

⚫ VBIAS Voltage Range: 2.7V to 5.5V

⚫ VOUT Voltage Range: 0.8V to 3.6V

⚫ Low Dropout: 50mV Typ. at 1A, VBIAS = 5V

⚫ 2% Accuracy Over Line/Load/ Temperature

⚫ PGOOD Indicator for Easy Sequence Control

⚫ Programmable Soft-Start Provides Linear

Voltage Startup

⚫ Stable with Any Output Capacitor  2.2F

⚫ Overcurrent and Over-Temperature Protection

3 Applications

⚫ PCs, Servers, Modems, and Set-Top-Boxes

⚫ FPGA Applications

⚫ DSP Core and I/O Voltages

⚫ Instrumentation

⚫ Post-Regulation Applications

⚫ Applications With Sequencing Requirements