ADPD103BCBZRL7

Overview

The ADPD103BCBZRL7 is a multifunction photometric front end from Analog Devices, designed for optical measurement applications. It integrates an analog front end (AFE), a 14-bit ADC, a 20-bit burst accumulator, three LED drivers, and a timing core within a single chip. The device operates on a 1.8 V supply and communicates via an I2C interface. Key electrical specifications include a sampling frequency range of 0.122 Hz to 3.820 kHz, peak LED currents up to 250 mA, and current consumption as low as 94 µA in specific configurations. It supports up to eight optical inputs and features advanced ambient light rejection capabilities.

Feature Summary

• Fully integrated AFE, 14-bit ADC, and 20-bit burst accumulator enabling up to 27 bits of resolution per data read through sample averaging.
• Three independent LED drivers supporting peak currents from 8 mA to 250 mA with flexible pulse timing.
• Supports up to eight photodiode inputs with separate data registers for each LED/photodiode combination.
• Best-in-class ambient light rejection without requiring external optical filters on the photodiodes.

Applications

• Body-worn health and fitness monitors, such as heart rate monitoring devices.
• Clinical measurements including blood oxygen saturation (SpO2) analysis.
• Industrial monitoring systems requiring optical sensing.
• Background light measurement applications.

Procurement Notes

Verify the package type matches the design requirements, as the ADPD103 is available in both 28-lead LFCSP and 16-ball WLCSP packages. Confirm that the ordering suffix corresponds to the desired reel quantity and packaging format. Ensure compatibility with the 1.8 V I2C logic levels used by the host controller. Check for RoHS compliance status if required by the manufacturing process.

Selection Notes

Select this component when high integration is needed for photometric sensing, combining signal conditioning, conversion, and LED driving in one IC. Consider the 16-ball WLCSP for space-constrained designs or the 28-lead LFCSP for easier prototyping. Evaluate the power budget against the typical current consumption of ~100 µA to 455 µA depending on LED activity. Ensure the application benefits from the internal ambient light rejection to simplify optical filter requirements.

Part Context

The ADPD103 belongs to the ADPD family of photometric front ends from Analog Devices. It is specifically engineered for applications requiring precise optical signal acquisition with minimal external components. The device replaces discrete solutions involving separate amplifiers, ADCs, and LED drivers, thereby reducing board space and design complexity for wearable and clinical sensors.

Replacement Considerations

Publicly confirmed substitute part numbers are not provided in the source documentation. Designers should consult Analog Devices for alternative products within the ADPD series or other photometric front ends that match specific pinout or performance requirements.

FAQ

What is the maximum resolution achievable with the ADPD103?

The device offers a base 14-bit ADC resolution per pulse. By using the 20-bit burst accumulator and on-board sample-to-sample accumulator, it can achieve up to 27 bits of resolution per data read when averaging between 64 and 255 pulses.

How does the ADPD103 handle ambient light interference?

It features best-in-class ambient light rejection capability built into the analog front end. This allows for effective signal extraction without the need for additional optical filters on the photodiodes.

Can the ADPD103 operate with multiple LEDs simultaneously?

Yes, it includes three independent LED drivers. It supports dual time slot operation, allowing sequential stimulation of different LEDs and measurement of corresponding optical returns within a single sampling period.