STMicroelectronics’ introduces the L3751 synchronous buck controller to serve different applications from industrial equipment to battery-powered light electric vehicles. The 3.5 mm x 4.5 mm controller is also suited to use in telecom and networking equipment that features commonly used 24 V and 48 V buses.

Having a minimum on-time duration of 40 ns, the L3751 can support an extremely low duty cycle thereby permitting a large step-down ratio. This allows powering low-voltage devices directly without intermediate conversion, which helps simplify circuit design and lower bill-of-materials (BOM) costs. The device integrates a 7.5 V supply for the gate drivers.

In addition to having a wide supply-voltage range, the L3751 has 100 V tolerant inputs that allow operation in harsh electrical environments. The switching frequency is adjustable from 100 kHz to 1 MHz, giving designers flexibility to optimize circuit size, performance, and cost, through the selection of the external MOSFETs and passive components.

To enhance efficiency and minimize ripple, the L3751 operates in diode-emulation mode and with pulse skipping at light loads.

The L3751 provides extensive protection functions, including thermal protection, input under-voltage lockout, constant current protection with hiccup mode, and programmable current sensing. There is also an external Enable pin and open-collector power-good indicator.

The STEVAL-L3751V12, 100 W evaluation board, is available to help designers accelerate device selection in power-supply development.

The L3751 is in production now and available in a QFN20 package with wettable flanks that aid inspection, priced from $1.36 for orders of 1000 pieces.

Click here to learn more about L3751