TPA8304 140dB Range (1nA – 10mA) Logarithmic Converter

Description 

The TPA8304 is a logarithmic detector optimized for the  measurement of low frequency signal power in fiber optic  systems and offers a large dynamic range.  

Wide measurement range, accuracy and fast step response are  achieved, which is very suitable for the requirement of optic  system. 

The TPA8304 requires only a single positive supply of 5 V. Low  quiescent current and chip disable facilitate use in batteryoperated applications.

Features 

 7 full decades of range: 1nA to 10mA 

 Law conformance error: 0.2 dB from 10nA to 10mA 

 Fast step response: raising 0.2μs, falling 5μs for 10nA to  10μA input on INPT 

 Basic logarithmic intercept at 100 pA 

 Logarithmic slope of 200 mV/20dB (at the VLOG pin) 

 Optimized for fiber optic photodiode interfacing 

 Single-supply operation: 4.5 V to 5.5 V 

 Power down mode  

Applications 

 High accuracy optical power measurement 

 Wide range baseband log compression 

 Versatile detector for APC loops 

 EDFA