FTM Board Club
38 V, 1.5 A synchronous step-down switching regulator evaluation board based on the L6981CDR

The STEVAL-L6981CDR evaluation board is based on the L6981CDR synchronous monolithic step-down regulator capable of delivering up to 1.5 A DC. Its wide input voltage range makes the device suitable for a broad range of applications



The device implements peak current mode architecture in an SO 8L package with internal compensation to minimize design complexity and size.
The L6981 is available in low consumption mode (LCM) and low noise mode (LNM) versions.
LCM maximizes efficiency at light load with controlled output voltage ripple, making the device extremely suitable for battery-powered applications.
LNM makes the switching frequency constant and minimizes the output voltage ripple overload current range, meeting the specification for noise sensitive applications.
The EN pin manages the enable/disable function. The typical shutdown current is 2 μA when disabled. When the EN pin is pulled up, the device is enabled and the internal 1.3 ms soft-start takes place.
Pulse-by-pulse current sensing on both power elements implements effective constant current protection while thermal shutdown prevents thermal run-away.

  • 3.5 V to 38 V operating input voltage
  • Output voltage from 0.85 V to VIN
  • 1.5 A DC output current
  • Internal compensation network
  • Two different versions: LCM for high efficiency at light loads and LNM for noise sensitive applications
  • 2 μA shutdown current
  • Internal soft-start
  • Enable function
  • Overvoltage protection
  • Output voltage sequencing
  • Thermal protection
  • SO 8L package
  • Synchronization with external clock for LNM devices