DC/DC converter offers greater flexibility to maximize efficiency and safety

STMicroelectronics has introduced the L7983, a 3 V to 60 V, 300 mA synchronous DC/DC buck converter with dynamic-mode selection to meet noise-sensitive applications and maximize efficiency at light load. In addition, the buck converters offer wide input voltage and switching frequency ranges for greater design flexibility.

The L7983 allows control of the low-side power MOSFET to provide a low-noise mode (LNM) with a constant switching frequency and an alternative low-consumption mode (LCM). In LCM, the converter maximizes the efficiency while powering low or idle loads, said ST, and the mode is selected using an external pin that can be controlled dynamically by the application or preset.

With its wide input-voltage range of 3 V to 60 V, the L7983 can operate from 12-V and 24-V industrial buses with a greater safety margin, according to ST. The devices target battery-powered applications, industrial fail-safe systems, decentralized intelligent nodes, appliances, robotics, telecom equipment, and precision-sensing applications.

In addition, the L7983 offers a wide switching frequency range of 200 kHz to 2 MHz and an optional spread-spectrum dithering to minimize electromagnetic interference (EMI). Another key feature is the low quiescent current of 10µA for a minimal impact on system power demand. It also provides an external enable pin that reduces the current to 2.3 µA in shutdown mode.

Other features include support for power sequencing and synchronization to an external clock, and integrated compensation circuitry for simpler design. It also includes built-in safety and protection such as soft-start, over-temperature protection, current limiting with pulse-by-pulse sensing, over-voltage protection, and adjustable under-voltage lockout (UVLO) according to the input voltage.

The L7983 (3 x 3 mm DFN10 package) is in production and is priced from $1.00 for orders of 1000 units. Three L7983 variants are available, comprised of the L7983PU33R with a 3.3-V fixed output voltage, L7983PU50R with a 5.0-V fixed output voltage, and L7983PUR with an adjustable output voltage. An evaluation board is available for each device: STEVAL-L7983V33 (L7983PU33R),  STEVAL-L7983V50 (L7983PU50R), and STEVAL-L7983ADJ (L7983PUR).