SLVSFQ6A November 2020 – June 2021 TPS2640
PRODUCTION DATA
During a transient output short circuit event, the current through the device increases very rapidly. As the currentlimit amplifier cannot respond quickly to this event due to its limited bandwidth, the device incorporates a fast-trip comparator, with a threshold I(FASTRIP). The fast-trip comparator turns off the internal FET within 250 ns (typical), when the current through the FET exceeds I(FASTRIP) (I(OUT) > I(FASTRIP)), and terminates the rapid short-circuit peak current. The fast-trip threshold is internally set to 87% higher than the programmed overload current limit (I(FASTRIP) = 1.87 × I(OL) + 0.015). The fast-trip circuit holds the internal FET off for only a few microseconds, after which the device turns back on slowly, allowing the current-limit loop to regulate the output current to I(OL). Then, device behaves similar to overload condition. Figure 9-12 and Figure 9-13 illustrate the behavior of the system when the current exceeds the fast-trip threshold.
VIN = 24 V, RILIM = 5.36 kΩ |