This Zetex 700 series array provides automatic control of LED brightness over a 1400:1
range with just three external components - a photodiode, LED and capacitor. Additionally,
the peak LED current can be set with one time programming (OTP) by on-chip fuses.
The circuit can operate at just 1µA total current with the LED illuminated at low
duty cycles. A shutdown mode drops the current to leakage values.
Two control pins allow the chip to be controlled using a digital circuit or microcontroller
to further extend the brightness operating range and to provide manual brightness
operation and remote shutdown.