UCC3585 Low Voltage Synchronous Buck Controller | TI.com

This product continues to be in production to support existing customers.
Low Voltage Synchronous Buck Controller

Low Voltage Synchronous Buck Controller - UCC3585

This product is not recommended for new designs.

Replaced By LM2745 – The device has SIMILAR FUNCTIONALITY but is not functionally equivalent to the compared device.

TI does not recommend using this part in a new design. This product continues to be in production to support existing customers.


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 pulse-by-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.

The UCC3585 also includes undervoltage lockout, a logic controlled enable, and softstart functions. The UCC3585 is offered in the 16-pin surface mount and through-hole packages.


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