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.