AP64350/351/352 and AP64500/501 Synchronous Buck Converters

Diodes' AP64350, AP64351, AP64352, AP64500, and AP64501 are all 40 V, high-efficiency, synchronous DC-DC buck converters. The special design of the gate drive/bootstrap enables them to operate in LDO mode, allowing near 100% duty cycle. As the load current approaches zero, the devices enter pulse frequency modulation (PFM) mode to increase the converter power efficiency. The AP64350, AP64351, AP64352, AP64500, and AP64501 devices feature frequency spread spectrum (FSS) (±6% switching frequency jitter) to reduce EMI by not allowing emitted energy to stay at any one frequency for any significant time.

The AP64350, AP64352, and AP64500 have programmable switching frequencies, up to 2.2 MHz, that can also be synchronized to an external clock. AP64351 and AP64501 have a nominal 570 kHz switching frequency. The AP64351, AP64352, and AP64501 have a programmable soft-start that reduces inrush currents, while the AP64350, AP64351, AP64500, and AP64501 have external compensation to optimize the loop response. All these Diodes converters are in the SO-8EP package, and there are evaluation boards available for each.