ST L7983 300mA Synchronous DC/DC Buck Converter
Supports low-noise mode and low-power mode selection features
Provides a switching frequency range of 200kHz to 2MHz


On the 11th, STMicroelectronics released the L7983, a compact 3V to 60V 300mA synchronous DC/DC buck converter that provides flexible dynamic mode selection to meet noise-sensitive application requirements and maximize efficiency at light loads.

The L7983 controls a low-side power MOSFET to provide Low-Noise Mode (LMM) and Low-Consumption Mode (LCM) with a constant switching frequency. In LCM mode, power is supplied to low or idle loads while maximizing converter efficiency. Mode selection can be achieved by fixing an external pin to a high or low signal or through dynamic control by the application.

The L7983 provides a wide input voltage range, making it suitable for 12V and 24V industrial buses, battery-powered applications, industrial fail-safe systems, distributed intelligent nodes, home appliances, robotics, communication equipment, and precision sensing applications.

It supports a switching frequency range of 200kHz to 2MHz, providing design flexibility. Spread-spectrum dithering is available as an option to minimize EMI. With a standby current of only 10µA, it minimizes the impact on system power demand and provides an external enable pin that reduces current to 2.3µA in shutdown mode.

Among the additional features is support for synchronization with an external clock and power sequencing. Built-in safety and protection functions include soft-start, overtemperature protection, current limiting via pulse-by-pulse detection, overvoltage protection, and input-voltage adjustable Under-Voltage Lockout (UVLO). An integrated compensation circuit is also provided.

The L7983 is available in three variants: the L7983PU33R with a fixed output voltage of 3.3V, the L7983PU50R with a fixed output voltage of 5.0V, and the L7983PUR with adjustable output voltage. Evaluation boards for each product—STEVAL-L7983V33 (L7983PU33R), STEVAL-L7983V50 (L7983PU50R), and STEVAL-L7983ADJ (L7983PUR)—are also supported. The L7983 is manufactured in a 3mm × 3mm DFN10 package, and the price is $1 for every 1,000 units purchased.