JAJSST5A June 2015 – February 2024 LV14540
PRODUCTION DATA
The LV14540 operates in pulse skipping mode (PSM) at light load current to improve efficiency by reducing switching and gate drive losses. If the output voltage is within regulation and the peak switching current at the end of any switching cycle is below the current threshold of 300 mA, the device enters PSM. The PSM current threshold is the peak switch current level corresponding to a nominal internal COMP voltage of 400 mV.
When in PSM, the internal COMP voltage is clamped at 400 mV, the high-side MOSFET is inhibited, and the device draws about 120 μA input quiescent current. Because the device is not switching, the output voltage begins to decay. The voltage control loop responds to the falling output voltage by increasing the internal COMP voltage. The high-side MOSFET is enabled and switching resumes when the error amplifier lifts internal COMP voltage above 400 mV. The output voltage recovers to the regulated value, and internal COMP voltage eventually falls below the PSM threshold at which time the device again enters PSM.