The SZDL3105B-BQXC from Silanna Semiconductor is a synchronous buck DC/DC converter that converts an input voltage of 7 - 27 V to an output voltage of 3.3 – 21 V. It consists of a buck converter regulator, ramp generator, on-time generator, LDO, a level shifter, HS driver, LS driver, delay, fault management, and low-side FET current sense circuitries. This converter is intended to be used in conjunction with USB port controllers and is developed for maximum efficiency performance throughout a wide output voltage range, incorporating dual input LDOs for self-bias.
The SZDL3105B-BQXC is designed to supply the full range of VBUS rails for USB-PD SPR ports and can be controlled by popular USB-PD controllers or fast-charging devices. It employs an internal feedback path at start-up to allow safe regulation until the external PD controller powers up and becomes available to regulate the output voltage. This converter hands over output control to the external PD controller following initial start-up. It consists of over-current protection, over-voltage protection, and over-temperature protection circuitries to prevent over-load-related damages. It is available in a surface-mount package that measures 4 x 4 mm and is ideal for VBUS supply generation for USB-PD ports, including multiple output USB-PD chargers, charging hubs, displays and televisions, and laptop docking station applications.