ADL5309ACBZ-R7

Overview

The ADL5309ACBZ-R7 is a dual-channel logarithmic converter featuring monolithic logarithmic transimpedance amplifiers optimized for measuring low-frequency and wide dynamic range optical signal power in fiber optic systems. It provides highly accurate, temperature-compensated output voltages proportional to the logarithm of input current relative to an internal reference. The device supports adaptive photodiode biasing via PDB1 and PDB2 interfaces to minimize dark current and saturation effects. An integrated 14-bit SAR ADC samples channel outputs and a digital temperature sensor, accessible through an I2C interface. It operates from 2.85 V to 5.25 V with a quiescent current of 57 mA.

Feature Summary

• Dual-channel current inputs enable direct optical gain measurements with high accuracy.
• Adaptive photodiode biasing minimizes dark current at low levels and prevents saturation at high currents.
• Integrated 14-bit ADC allows digital readout of logarithmic outputs and temperature data via I2C.
• Factory-trimmed logarithmic response ensures precise slope and intercept calibration.

Applications

• Automatic test equipment
• Optical power monitoring
• Machine automation
• Optical modules

Procurement Notes

Verify the specific suffix R7 indicates reel packaging when sourcing. Confirm the ACBZ designation matches the required WLCSP package and industrial temperature range. Ensure I2C address configuration via the SBA pin aligns with system bus requirements. Check for any recent revision changes in the datasheet that may affect timing or electrical specifications.

Selection Notes

Select this component for applications requiring wide dynamic range optical power measurement with minimal external components. The dual-channel architecture is suitable for differential or multi-sensor setups. Consider the small WLCSP footprint for space-constrained designs. Verify that the I2C interface speed and addressing capabilities meet the controller's requirements.

Part Context

This part belongs to the ADL5309 series of logarithmic converters from Analog Devices. It is designed specifically for fiber optic systems where accurate monitoring of signal power over a broad range is critical. The device integrates analog front-end processing with digital conversion, reducing the need for external precision amplifiers or ADCs.

Replacement Considerations

Public confirmed substitute part numbers are not available in the provided documentation.

FAQ

How does the ADL5309 handle photodiode biasing?

It uses adaptive photodiode biasing through PDB1 and PDB2 pins. At low currents, reverse bias is kept small to minimize dark current. At higher currents, bias voltage scales linearly to avoid saturation.

What is the function of the SUM pins?

The SUM pins act as guard pins to shield current lines to INP1 and INP2. They are internally connected together and should not be grounded.

Can multiple ADL5309 devices share an I2C bus?

Yes, up to three devices can communicate independently on a single I2C bus by configuring the Serial Bus Address (SBA) pin to different voltage levels.