DC/DC controller dramatically reduces switching jitter

Maximising converter efficiency and increasing power density, power inductor DCR as low as 0.2mΩ can be used without a sense resistor. This DCR sensing technique dramatically reduces the switching jitter normally associated with low DCR sensing applications. The LTC3875 is suited for applications including high current power distribution, redundant (n+1) supplies, industrial systems, processor and ASIC power. The maximum output current is precisely limited over temperature thanks to precise current sense limits and DCR temperature compensation.

Operating over a temperature range from -40 to 125°C, the LTC3875 features dual onboard differential amplifiers to provide true remote output voltage sensing of both output voltages. Enabling up to 12 phases to be paralleled and clocked out-of-phase minimises input and output filtering. Suitable for current requirements up to 360A, the LTC3875 maintains less than ±5% current mismatch between phases with both outputs paralleled.

The LTC3875 employs powerful 1.1 Ohm onboard all N-channel gate drivers in order to minimise MOSFET switching losses; while it offers either a selectable fixed operating frequency of 250-720kHz or synchronisation to an external clock. Minimising power losses, the DC/DC controller's adjustable current limit can be configured for very low sense voltages of 10-30mV. Featuring a fast transient circuit, the second channel improves the load-step-up transient by up to 30%. Additionally, the Linear controller features adjustable soft-start or tracking, foldback current limit, short-circuit soft recovery, output overvoltage protection and a power good output voltage monitor.

Available now in a 40-lead 6x6mm QFN package, the LTC3875 is priced from $3.47 (USD) each in 1,000 unit quantities.