The LM5192 is in
active mode when VEN is above the precision enable threshold, the internal bias
rail is above the UV threshold level, and when the CONTROLLER_EN bit in the OPERATION register is set. In
active mode, the device operates in one of two modes depending on the load current, input
voltage, output voltage, and PFM / SYNC pin configuration:
- Forced pulse width modulation (FPWM) mode. This
mode of operation is configured by tying the PFM / SYNC pin to GND or driving with an
external clock source. The device operates in continuous conduction mode (CCM) with fixed
switching frequency regardless of the load current.
- Pulse frequency modulation (PFM) mode. This mode
of operation is configured by tying the PFM / SYNC pin to VDDA. The device operates in
discontinuous conduction mode (DCM) if the load current is less than half of the
peak-to-peak inductor current, otherwise the device operates in continuous conduction mode
(CCM). The transition between CCM and DCM is automatic.