FEATURES

Step-Down Controller for Applications With

up to 95% Efficiency

1.8-V to 6.5-V Operating Input Voltage Range

Adjustable Output Voltage Range From 1.2 V

to VI

High Efficiency Over a Wide Load Current

Range

100% Maximum Duty Cycle for Lowest

Dropout

Internal Softstart

20-μA Quiescent Current (Typical)

Overcurrent Protected

Available in a SOT23 Package

APPLICATIONS

USB Powered Peripherals

Organizers, PDAs, and Handheld PCs

Low Power DSP Supply

Digital Cameras

Hard Disk Drives

Portable Audio Players

DESCRIPTION

The TPS6420x are nonsynchronous step-down

controllers that are ideally suited for systems powered

from a 5-V or 3.3-V bus or for applications powered from

a 1-cell Li-Ion battery or from a 2- to 4-cell NiCd, NiMH, or

alkaline battery. These step-down controllers drive an

external P-channel MOSFET allowing design flexibility. To

achieve highest efficiency over a wide load current range,

this controller uses a minimum on time, minimum off time

control scheme and consumes only 20-μA quiescent

current. The minimum on time of typically 600 ns

(TPS64203) allows the use of small inductors and

capacitors. When disabled, the current consumption is

reduced to less than 1 μA. The TPS6420x is available in

the 6-pin SOT23 (DBV) package and operates over a free

air temperature range of ?40°C to 85°C.