AD8304 Datasheet

• Optimized for Fiber Optic Photodiode Interfacing
• Eight Full Decades of Range
• Single-Supply Operation
  (3.0 V– 5.5 V)
• Complete and Temperature Stable
• 1-, 2-, or 3-Pole Low-Pass Filtering at Output
• Miniature 14-Lead Package (TSSOP)
• Accurate Laser-Trimmed Scaling:
  Logarithmic Slope of 10 mV/dB (at VLOG Pin)
  Basic Logarithmic Intercept at 100 pA
  Easy Adjustment of Slope and Intercept
• Output Bandwidth of 10 MHz, 15 V/µs Slew Rate
• Low Power: ~4.5 mA Quiescent Current (Enabled)

• High Accuracy Optical Power Measurement
• Wide Range Baseband Log Compression
• Versatile Detector for APC Loops

The AD8304 is a monolithic logarithmic detector optimized for the measurement of low frequency signal power in fiber optic systems. It uses an advanced translinear technique to provide an exceptionally large dynamic range in a versatile and easily used form. Its wide measurement range and accuracy are achieved using proprietary design techniques and precise laser trimming. In most applications only a single positive supply, V_P, of 5 V will be required, but 3.0 V to 5.5 V can be used, and certain applications benefit from the added use of a negative supply, V_N. When using low supply voltages, the log slope is readily altered to fit the available span. The low quiescent current and chip disable features facilitate use in battery-operated applications.

The AD8304 is available in a 14-lead TSSOP package and specified for operation from -40°C to +85°C.