LTM8028 TechClips - 36VIN, UltraFast, Low Output Noise 5A μModule Regulator

The LTM8028 is a 1mV output ripple μModule (micromodule) regulator designed to power data converters and high speed transceivers. The low output ripple minimizes random jitter in high speed data transceivers for superior bit error rate (BER) performance. When powering an analog-to-digital converter (ADC), tests showed a 13dB improvement in spurious free dynamic range (SFDR) with the LTM8028 compared to a typical step-down regulator. The μModule regulator combines a 36V synchronous step-down switcher, powering a 5A linear post-regulator in a compact 15mm x 15mm x 4.92mm BGA package. To minimize power dissipation and voltage drop across the linear regulator, the linear regulator automatically adjusts the output voltage of the internal synchronous regulator.

The LTM8028 maintains tight regulation with just 5mV total deviation over a load range of 0A – 5A and ambient temperature of 21°C to 115°C. Under a 0.5A to 5A load transient, the output voltage deviates by approximately ±30mV for a 1.2V output.

With a 5A load, the LTM8028 has a maximum spur of -73dBm occurring at the switching frequency. Steady state output ripple is less than 1mV under the same load.

Under a 5A load at the maximum output voltage of 1.8V, the LTM8028 exhibits a thermal rise of just +33°C with a 12V input and +37°C with a 24V input.