SNVSAJ6D July 2016 – December 2017 LM5141-Q1
PRODUCTION DATA.
A fully synchronous buck controller implemented with a free-wheel MOSFET rather than a diode has the capability to sink negative current from the output in certain conditions such as light load, over-voltage, and pre-bias start-up. The LM5141-Q1 provides a diode emulation feature that can be enabled to prevent reverse (drain to source) current flow in the low-side free-wheel MOSFET. The diode emulation feature is configured with the DEMB pin. To enable diode emulation, connect the DEMB pin to ground. When configured for diode emulation, the low-side MOSFET is disabled when reverse current flow is detected. The benefit of this configuration is lower power loss at no load or light load conditions and the ability to turn on into a pre-biased output without discharging the output. The negative effect of diode emulation is degraded light load transient response times. Enabling the diode emulation feature is recommended to allow discontinuous conduction operation. If continuous conduction operation is desired, the DEMB pin should be tied to VDDA.
DEMB PIN | MODE |
---|---|
1 | FPWM |
0 | DEMB |
CLK | FPWM |