1 Features

• Low output 1/f 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, 1.4-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

• 25-mΩ/6.5-mΩ RDSon

• Output voltage accuracy of ±1 over temperature

• Precise enable input allows

– User-defined undervoltage lockout

– Exact sequencing

• Adjustable soft start

• Power-good output

• Output discharge (optional)

• –40°C to 150°C junction temperature range

• 2.5-mm × 3.0-mm QFN with 0.5-mm pitch

• Create a custom design using the TPS6291x with

the WEBENCH® Power Designer

2 Applications

• Telecom infrastructure

• Test and measurement

• Aerospace and defense (radar, avionics)

• Medical

3 Description

The TPS6291x devices are a family of high-efficiency,

low noise, and low ripple current mode synchronous

buck converters. The devices are designed for noise

sensitive applications that normally use an LDO for

post regulation such as high-speed ADCs, clock

and jitter cleaner, serializer, de-serializer, and radar

applications.

To reduce the output voltage ripple, the device

loop compensation is designed to operate with an

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

noise levels, similar to a low-noise LDO,

are further achieved by filtering the internal voltage

reference with a capacitor connected to the NR/SS

pin. Combined, these features allow for an output

voltage ripple below 10 μVRMS.

The device operates at a fixed switching frequency

of 2.2 MHz, 1.4 MHz, or 1 MHz, and can be

synchronized to an external clock. An optional spread

spectrum modulation scheme spreads the DC/DC

switching frequency over a wider span, which lowers

the mixing spurs.