Low ripple buck converter with integrated ferrite bead filter compensation

The Texas Instruments TPS6291x devices are a family of high-efficiency low noise and low ripple synchronous buck converters. The devices are excellent for noise-sensitive applications that would usually employ an LDO for post-regulation such as high-speed ADCs, clock and jitter cleaner, serialiser, de-serialiser, and radar applications.

The device functions at a fixed switching frequency of 2.2MHz or 1MHz and can be synchronised to an external clock.

To further decrease the output voltage ripple, the device combines loop compensation to operate with an optional second-stage ferrite bead L-C filter. This provides an output voltage ripple below 10µVRMS.

Low-frequency noise levels, similar to a low-noise LDO, are accomplished by filtering the internal voltage reference with a capacitor connected to the NR/SS pin.

The optional spread spectrum modulation scheme expands the DC-DC switching frequency across a wider span, which lowers the mixing spurs.