User Manual
This application note focuses on the control circuitry, using the ADuC832 MicroConverter IC and the AD8305 logarithmic converter, for a MEMS based, silicon, optical Closed-Loop Control Circuit Implementation of the ADuC832 MicroConverter® IC and the AD8305 Logarithmic Converter in a Digital Variable Optical Attenuator.
Datasheet
AD8305 is a 100 dB dynamic range 10 nA to 1 mA current converter produced by Analog Devices. It has the following features: 1. Optimized for fiber optic photodiode interface; 2. Measures current over 5 decades; 3. Conforms to 0.1 dB from 10 nA to 1 mA of the law; 4. Single- or dual-supply operation (3 V to 12 V total); 5. Has full log-ratio capabilities; 6. Nominal slope of 10 mV/dB (200 mV/decade); 7. Nominal intercept of 1 nA (set by external resistor); 8. Optional adjustment of slope and intercept; 9. Completely and temperature stable; 10. Rapid response time for a given current level; 11. Miniature 16-lead chip scale package (LFCSP 3 mm × 3 mm); 12. Low power: ~5 mA quiescent current.
