ZHCSQD4A october 2022 – march 2023 TPS62993-Q1
PRODUCTION DATA
The TPS62993-Q1 is protected against overload and short-circuit events. If the inductor current exceeds the high-side FET current limit (ILIMH), the high-side switch is turned off and the low-side switch is turned on to ramp down the inductor current. The high-side FET turns on again only if the current in the low-side FET has decreased below the low-side FET current limit threshold AND the internal ILIM recovery delay has expired.
Due to internal propagation delay, the actual current can exceed the static current limit during that time. The dynamic current limit is given as Equation 2:
where
The current limit can exceed static values, especially if the input voltage is high and very small inductance is used. The dynamic high-side switch peak current can be calculated as follows:
The TPS62993-Q1 also includes a low-side negative current limit (ILIM:SINK) to protect against excessive negative currents that can occur in forced PMW mode under heavy to light load transient conditions. If the negative current in the low-side switch exceeds the ILIM:SINK threshold, the low-side switch is disabled. Both the low-side and high-side switches remain off until an internal timer re-enables the high-side switch based on the selected PWM switching frequency.