1 Features

? Low output 1/f noise < 20μVRMS

(100Hz to 100kHz)

? Low output voltage ripple < 10μVRMS after ferrite

bead

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

? 2.2MHz, 1.4MHz, or 1.0MHz fixed frequency peak

current mode control

? Synchronizable with external clock (optional)

? Integrated loop compensation supports ferrite

bead for second stage L-C filter with 30dB

attenuation (optional)

? Spread spectrum modulation (optional)

? 3.0V to 17V input voltage range

? 0.8V to 5.5V output voltage range

? 25mΩ/7mΩ 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. mm × 3.0mm QFN with 0.5mm 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 10μVRMS.

The device operates at a fixed switching frequency of

2.2MHz, 1.4MHz, or 1MHz, 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.