AD8305ACPZ-RL7

Overview

The AD8305ACPZ-RL7 is a microminiature logarithmic converter optimized for fiber optic photodiode interfacing. It measures input current over a 100 dB dynamic range (10 nA to 1 mA) with a nominal slope of 10 mV/dB and intercept of 1 nA. Operating on a single supply from 3 V to 12 V, it features a low quiescent current of approximately 5 mA. The device includes an integrated buffer amplifier with rail-to-rail output swing and a 2.5 V reference output. It is housed in a 16-lead LFCSP package rated for operation between -40°C and +85°C.

Feature Summary

• Optimized for fiber optic photodiode interfacing with wide dynamic range
• Integrated buffer amplifier for load driving and signal scaling
• Temperature-stable translinear logarithmic conversion technique
• Supports log-ratio mode for measuring current or voltage ratios

Applications

• Optical power measurement
• Wide range baseband logarithmic compression
• Measurement of current and voltage ratios
• Optical absorbance measurement

Procurement Notes

Verify the specific ordering suffix RL7 corresponds to the required reel packaging configuration before procurement. Confirm that the 16-lead LFCSP package dimensions align with the target PCB footprint. Ensure the operating temperature range meets the environmental requirements of the final assembly. Check for any specific humidity sensitivity handling instructions during storage and soldering processes.

Selection Notes

Select this component when a high-dynamic-range logarithmic response is required for small photocurrents. It is suitable for battery-operated applications due to its low quiescent current consumption. Consider the internal 2.5 V reference if external precision references are not available. Evaluate the need for the integrated buffer amplifier to drive subsequent stages or filters directly.

Part Context

This part belongs to the AD8305 family of logarithmic converters manufactured by Analog Devices. It is designed as a cost-effective solution for determining optical power in fiber optic systems. The device utilizes a classic translinear junction-based technique to achieve precise logarithmic conversion within a miniature form factor.

Replacement Considerations

Public confirmed substitute part numbers: AD8304, ADL5310.