FEATURES
VOUT Resistor Programmable Down to 0.9 V
3.3-V or 5.0-V Input Supply
1% DC Accuracy
High Efficiency Synchronous Switching
Drives P-Channel (High Side) and N-Channel
(Low Side) MOSFETs
Lossless Programmable Current Limit
Logic Compatible Shutdown

APPLICATIONS
Local Microprocessor Core Voltage Power
Supplies for Desktop and Notebook
Computers
DSP Core or I/O Powering
High-Speed GTL Bus Regulation

DESCRIPTION
The UCC3585 synchronous buck controller
provides flexible high efficiency power conversion
for output voltages as low as 0.9 V with ensured
±1% dc accuracy. With an input voltage range of
3.0 V to 5.5 V, it is the ideal choice for 3.3 V only,
5.0 V only, or other low voltage systems. The fixed
frequency oscillator is capable of providing
practical PWM operation to 500 kHz.
The UCC3585 drives a complementary pair of
power MOSFET transistors. A P-channel on the
high side, and an N-channel on the low side step
down the input voltage at up to 90% efficiency.
A programmable two-level current limiting
function is provided by sensing the voltage drop
across the high side P-channel MOSFET. This
circuit can be configured to provide pulseby-
pulse limiting, timed shutdown after seven
consecutive faults, or latch-off after fault detection,
allowing maximum application flexibility. The
current limit threshold can be programmed over a
wide range with a single resistor.