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.