12A ultrathin µModule regulators mount on PCB underside

October 28, 2016 // By Graham Prophet
Configurable as quad, triple, dual or single output, the LTM4643 quad output step-down µModule [micromodule] (power module) regulator deliver, respectively, 12A, 6A & 6A or 9A & 3A, or 4 x 3A from a 9 x 15 x 1.82 mm ultrathin LGA package.

This flexibility enables system designers to rely on one simple and compact µModule regulator for a variety of voltage and load current requirements in FPGA, GPU, ASIC and processor-based applications. The 1.82 mm height ultrathin package allows the LTM4643 to be mounted on the backside of the PCB, freeing space on the topside. The LTM4643 is suitable for systems with height restrictions, such as backside PCB assembly in PCIe applications and where the regulator must fit under a common heat sink or cold plate to cool high power FPGAs, GPUs, ASICs and processors in applications such as embedded computing, data storage, medical imaging and industrial systems.

 

Only eight external ceramic capacitors (1206 or smaller case sizes) and four feedback resistors (0603 case size) are required to regulate four independently adjustable outputs between 0.6V to 3.3V. Separate input pins enable powering of the four channels from different or a common supply rail(s) from 4V to 20V.

 

The four channels are switched 90° out-of-phase to minimize input ripple at the 1.2 MHz default switching frequency or synchronized to an external clock between 850 kHz and 1.5 MHz. With the addition of an external bias supply above 4V, the LTM4643 can regulate from an input supply voltage as low as 2.375V. Output overvoltage, overcurrent and overtemperature fault protection are included in the regulator.

 

The LTM4643 is available with operation specified over the –40°C to 125°C internal temperature range, for $19.90 (1000).

 

Linear Technology; www.linear.com/product/LTM4643