3-output regulator module delivers 70W from 4.5cm² PCB area

September 01, 2014 // By Graham Prophet
LTM4634 is a triple output step-down µModule (micromodule) regulator in a 15 x 15 x 5.01 mm BGA package with integrated heat sink. The thermally efficient package enables the LTM4634 to deliver full current on all three outputs (5A, 5A, and 4A), more than 70W of output power at 65°C ambient with 200 LFM airflow.

Combined with only 13 ceramic capacitors and three resistors, the LTM4634 solution fits within 4.5cm² on a dual-sided PCB. The LTM4634 includes three DC/DC controllers, power switches, inductors and compensation in a single package. The regulated output voltage for channels 1 and 2 is adjustable between 0.8V to 5.5V, with the third channel from 0.8V to 13.5V, each with ±1.5% accuracy over line, load and temperature. The combination of wide output voltage range, a thermally efficient package, tight regulation accuracy and small solution size suits the LTM4634 to regulate common intermediate power buses such as 12V, 5V and 3.3V in instrumentation, communications and industrial applications.

The LTM4634's three switchers operate from an input voltage from 4.75V to 28V. Separate input power pins for each switcher enables channel one and/or channel two to be supplied from a 12.5V, 50W intermediate bus generated from channel three. The three switchers, operating from the same internal or optional external clock signal, are internally phase shifted by 120° to minimise input ripple. For loads in excess of 5A, channels 1 and 2 can be paralleled to support up to 10A. Output overvoltage and overcurrent fault protection are included in the regulator. The LTM4634's internal temperature can be observed via two internal temperature diode monitors located next to the power stages.

In the -40°C to +125°C internal operating temperature grade the device costs $35.95 (1,000).

Linear Technology; www.linear.com/product/LTM4634