ZHCSLJ2B September 2020 – July 2021 TPS62868 , TPS62869
PRODUCTION DATA
The switch current limit prevents the device from high inductor current and from drawing excessive current from the battery or input voltage rail. Excessive current can occur with a shorted or saturated inductor or a heavy load or shorted output circuit condition. If the inductor current reaches the threshold ILIM, cycle by cycle, the high-side MOSFET is turned off and the low-side MOSFET is turned on, while the inductor current ramps down to the low-side MOSFET current limit.
When the high-side MOSFET current limit is triggered 32 times, the device stops switching. The device then automatically re-starts, with an internal soft start-up, after a typical delay time of 128 μs has passed. This is named HICCUP short-circuit protection. The device repeats this mode until the high load condition disappears.
The HICCUP is disabled by the CONTROL register bit Enable HICCUP. Disabling HICCUP changes the overcurrent protection to latching protection. The device stops switching after the high-side MOSFET current limit is triggered 32 times. Toggling the EN pin, removing and reapplying the input voltage, or writing to the CONTROL register bit Software Enable Device unlatches the device.