1 Features

• Low output noise < 20 μVRMS

(100 Hz to 100 kHz)

• Low output voltage ripple < 10 μVRMS after ferrite

bead

• High PSRR of > 65 dB (up to 100 kHz)

• 2.2-MHz or 1-MHz fixed frequency peak current

mode control

• Synchronizable with external clock (optional)

• Integrated loop compensation supports ferrite

bead for second stage L-C filter with 30-dB

attenuation (optional)

• Spread spectrum modulation (optional)

• 3.0-V to 17-V input voltage range

• 0.8-V to 5.5-V output voltage range

• 57-mΩ/20-mΩ RDSon

• Output voltage accuracy of ±1

• Precise enable input allows

– User-defined undervoltage lockout

– Exact sequencing

• Adjustable soft start

• Power-good output

• Output discharge (optional)

• –40°C to 125°C junction temperature range

– –55°C to 125°C for -ET versions

• Create a custom design using the TPSM8291x

with the WEBENCH® Power Designer

2 Applications

• Telecom infrastructure

• Test and measurement

• Aerospace and defense (radar, avionics)

• Medical

3 Description

The TPSM8291x devices are a family of highefficiency,

low-noise and low-ripple current mode

synchronous buck power modules. The devices are

ideal for noise sensitive applications that would

normally use an LDO for post regulation such as

high-speed ADCs, clock and jitter cleaner, serializer,

de-serializer, and radar applications.

The devices operate at a fixed switching frequency of

2.2 MHz or 1 MHz and can be synchronized to an

external clock.

To further reduce the output voltage ripple, the device

integrates loop compensation to operate with an

optional second-stage ferrite bead L-C filter. This

feature allows an output voltage ripple below 10

μVRMS.

Low-frequency noise levels, similar to a low-noise

LDO, are achieved by filtering the internal voltage

reference with an integrated capacitor on the NR/SS

pin. An external capacitor can be added to the module

for additional filtering.

The optional spread spectrum modulation scheme

spreads the DC/DC switching frequency over a wider

span, which lowers the mixing spurs.