SNVSC74A September 2023 – July 2024 LP5813
PRODUCTION DATA
The LP5813 uses a valley current limit sensing scheme. The inductor current is detected during the switching off-time, by sensing the voltage across the synchronous rectifier.
When the load current increases, such that the inductor current is above the current limit within the whole switching cycle , the off-time increases to discharge the inductor current. The current decreases below the limit before the next on-time. When the current limit is reached, the output voltage decreases if the load current continually increases.
The maximum continuous output current (IOUT(CL)), before entering current limit (CL) operation, can be defined by Equation 1.
where
The duty cycle can be estimated by Equation 2.
where
The peak-to-peak inductor ripple current is calculated by Equation 3.
where