SNVSA46B June 2014 – January 2018 LM46001
When the load current is lower than half of the peak-to-peak inductor current in CCM, the LM46001 operates in DCM, also known as diode emulation mode (DEM). In DCM operation, the LS FET is turned off when the inductor current drops to 0 A to improve efficiency. Both switching losses and conduction losses are reduced in DCM, comparing to forced PWM operation at light load.
At even lighter current loads, PFM is activated to maintain high efficiency operation. When the HS switch ON-time reduces to TON_MIN or peak inductor current reduces to its minimum IPEAK-MIN, the switching frequency reduces to maintain proper regulation. Efficiency is greatly improved by reducing switching and gate drive losses.