SNVSBW1C December 2021 – August 2024 LM63440-Q1 , LM63460-Q1
PRODUCTION DATA
Like AUTO mode operation, FPWM mode is selected as a factory option. FPWM applies by default during synchronization. In FPWM mode, the switching frequency is maintained constant while lightly loaded by allowing negative current to flow in the inductor. Negative current is limited to –3A for LM63460-Q1 and –2A for LM63440-Q1 devices by a reverse current limit circuit.
Frequency reduction is still available in FPWM mode if the output voltage is high enough to command minimum on time even while lightly loaded, allowing good behavior during faults that involve the output being pulled up.