The LED current can be turned on and off via the ADJ pin. By bringing this pin to ground or at least below 200 mV the ZXLD1350 turns off the LED driver transistor and the chip will take only 15 µA from the supply. When connecting directly to external control circuitry such as a microcontroller, it is advisable to put a 10k Ω resistor in series with the ADJ pin.

