FEATURES
Optimized for fiber optic photodiode interfacing 8 full decades of range Law conformance: 0.1 dB from 1 nA to 1 mA Single-supply operation: 3.0 V to 5.5 V Complete and temperature stable Accurate laser trimmed scaling Logarithmic slope of 10 mV/dB (at the VLOG pin) Basic logarithmic intercept at 100 pA Easy adjustment of slope and intercept Output bandwidth of 10 MHz, 15 V/µs slew rate Miniature 16-lead package (LFCSP) Low power: ~4.5 mA quiescent current (enabled) APPLICATIONS
High accuracy optical power measurement Wide range baseband log compression Versatile detector for APC loops GENERAL DESCRIPTION
Wide measurement range and accuracy are achieved using proprietary design and precise laser trimming. Low quiescent current and chip disable facilitate use in battery-operated applications. The input current, IPD, flows in the collector of an optimally scaled NPN transistor, connected in a feedback path around a low offset JFET amplifier. The current summing input node operates at a constant voltage, independent of current, with a default value of 0.5 V; this may be adjusted over a wide range.
Analog Devices
