I am trying to use a TTL input darlington sink driver chip to sink an active low LED down away the from the +5 volt rail and thus making it light when the chip select goes low. See circuit .pdf below. While the idea of sinking the cathode down to ground with the anode tied to +5V through a resistor seems easy enough and electrically should work, the only problem I've encountered is that the LED does not have enough time to fully light because the chip select signal only last 1.1 us (one cpu clock cycle). This is a peripheral and I want to see when there's activity on it. The purpose of the capacitor is to let it charge simultaneously while sink is occuring, and then when the sinking stops there will still be a little charge left to make the LED light for a longer period time. My question is, with the right component values, is this possible?
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