UDG-95106

ACTIVE LOW OUTPUTS DURING UVLO

UDG-95106

UDG-95108

UC1825A-SP

Anytime ILIM exceeds 1.2 V, the fault latch is set and the output pins are driven low. The soft-start cap is then

discharged by a 250-

µA current sink. No more output pulses are allowed until soft-start is fully discharged and

ILIM is below 1.2 V. At this point the fault latch resets and the chip executes a soft-start.

Should the fault latch get set during soft-start, the outputs are immediately terminated, but the soft-start capacitor

does not discharge until it has been fully charged first. This results in a controlled hiccup interval for continuous

fault conditions.

Figure 5. Soft-Start and Fault Waveforms

The UVLO function forces the outputs to be low and considers both VCC and VREF before allowing the chip to

operate.

Figure 6. Output Voltage vs Output Current

Figure 7. Output V and I During UVLO

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