3A step-down regulator boasts remarkable space savings

Linear Technology Corp. has unveiled the LTM4623 3A uModule (micromodule) step-down regulator packaged in a small footprint, enabling it to be mounted on the backside of the PCB that frees up space on the topside for components such as memory and FPGAs. The device supports 4-20V operation from input supplies and precisely regulates an output voltage from 0.6-5.5V with 1.5 per cent maximum total DC output voltage error, detailed the company.

The LTM4623 is offered in an ultrathin 1.8mm profile LGA package with only a 6.25 x 6.25mm footprint. With solder paste, the package height is less than 2mm, meeting the height restrictions of many PCIe, Advanced Mezzanine Cards (AMC) for AdvancedTCA carrier cards in embedded computing systems. Application samples include ultra-dense data storage, gateway controllers and 40-100Gb/s network equipment.

The solution fits in a 0.5cm² dual-sided PCB or <1cm² on a single-sided PCB. The circuit only requires one input capacitor and one output capacitor, a resistor to set VOUT, and a small capacitor for VOUT tracking and soft-start. With an auxiliary 5V bias, the LTM4623 operates from input supplies as low as 2.375V. The operating efficiency for converting 12VIN to 1.5VOUT and 3.3VOUT at 3A is 80 per cent and 88 per cent, respectively. Power loss for 12VIN to 1.5VOUT is 1.1W, resulting in only a 24°C rise in junction temperature. The LTM4623 is rated for operation from -40°C to 125°C. 1,000-piece pricing starts at $6.05 each.