The LMR516xx-Q1 is in active mode when both VEN and VIN are above the respective operating threshold. The simplest way to enable the LMR516xx-Q1 is to connect the EN pin to VIN pin. This action allows self-start-up when the input voltage is in the operating range of 4V to 65V. See Enable for details on setting these operating levels.
In active mode, depending on the load current, the LMR516xx-Q1 is in one of four modes:
- Continuous conduction mode (CCM) with fixed switching frequency when load current is greater than half of the peak-to-peak inductor current ripple (for both PFM and FPWM versions)
- Discontinuous conduction mode (DCM) with fixed switching frequency when load current is less than half of the peak-to-peak inductor current ripple(only for PFM versions)
- Pulse frequency modulation mode (PFM) when switching frequency is decreased at very light load (only for PFM version)
- Forced pulse width modulation mode (FPWM) with fixed switching frequency even at light load (only for FPWM version)