GENERAL DESCRIPTION

The ADL5304is a high speed logarithmic converter with fast response and low noise over a 200 dB (1 pA to 10 mA) measure ment range. The ADL5304provides a nominal logarithmic slope of 10 mV/dB (200 mV/decade); other values are easily configured. Logarithmic intercept can be programmed over a wide range with the internal 100 nA current source or externally for log ratio applications.

FEATURES

Optimized for very fast response at all input currents

  Overall bandwidth of >4 MHz for inputs >1 μA

  Bandwidth: 25 kHz at input of 1 nA and 350 kHz at 10 nA

10 decades of input range: 1 pA to 10 mA

Law conformance: ±0.25 dB from 100 pA to 100 μA

Log ratio or fixed-intercept operation

Precision voltage references and reference current

Adaptive photodiode (PD) bias for low dark current

Programmable log slope and intercept

Default log slope of 10 mV/dB at VLOG pin

Single- or dual-supply operation

APPLICATIONS

High accuracy optical power measurement

Wide range baseband log compression

Versatile detector for high speed APC loops