Latest 15A and 20A PoL regulators target next-generation servers

Exar has introduced the XR76116 (15A) and XR76120 (20A) point-of-load (PoL) step-down buck switching regulators which employ the latest generation of the company's patented emulated current mode constant on-time (CoT) control technology. The control loop provides the fast transient response required in demanding server applications while making implementation simple and easy. Improved gate driver technology has reduced dead times to 10ns, resulting in improved efficiency across the entire operating range. The XR76116 and XR76120 extend the output current range of the company's PowerBlox line of high-current PoL regulators up to 20A. The patented COT control loop enables operation with ceramic output capacitors without degradation in transient performance and eliminates loop compensation components, making a simpler and more reliable design. The regulators are housed in 5mm x 6mm TQFN packages. Additional features aimed server applications include a power good pin which maintains a low impedance when the chip is unpowered thereby avoiding false power good signals. Also, there is a second output voltage sense pin, ensuring any failure of the main feedback does not result on damaging voltages being applied to expensive low voltage digital circuitry. The units have exceptional full range 0.1% load regulation and 1% output accuracy over the full -40C to 125C temperature range. A host of supervisory and protection features for proper sequencing, safe operation under abnormal operating conditions and light load operation is built in, says the company. “The XR76116 and XR76120 POL regulators show Exar’s commitment to its key customers and the server market,” said Tuomas Hollman, Exar’s vice president, power management products. “These are the second set of power products Exar has developed for the server market. The Universal PMIC, XRP7725, was the first product also used in Skylake servers.”