The device is Active mode when VEN is
above the precision enable threshold voltage and VIN is above its respective UVLO
level. The simplest way to enable the device is to float the EN pin. This allows
self-start-up when the input voltage is in the operating range 4.2 V to 18 V.
In Active mode, depending on the load
current and the configuration of MODE pin, the device is in one of the following
modes:
- Continuous Conduction Mode
(CCM) operation with fixed switching frequency. When load current is above
half of the peak-to-peak inductor current ripple. The device works with PWM
regulation.
- Force Continuous Conduction
Mode (FCCM) operation with fixed switching frequency. No matter what the
load current is, the device works with PWM regulation.
- Discontinuous Conduction Mode
(DCM) operation with fixed switching frequency. When load current is lower
than half of the peak-to-peak inductor current ripple in CCM operation, the
device works with PWM regulation.
- Eco-mode operation with
switching frequency decreased at very light load, the device works with PFM
regulation.