Photometric Front Ends
ADPD1080/ADPD1081
Data Sheet
FEATURES
GENERAL DESCRIPTION
Multifunction photometric front end
The ADPD1080/ADPD1081 are highly efficient, photometric
front ends, each with an integrated 14-bit analog-to-digital
converter (ADC) and a 20-bit burst accumulator that works
with flexible light emitting diode (LED) drivers. The ADPD1080/
ADPD1081 stimulate an LED and measures the corresponding
optical return signal. The data output and functional configuration
occur over a 1.8 V I2C interface on the ADPD1080 or a serial
port interface (SPI) on the ADPD1081. The control circuitry
includes flexible LED signaling and synchronous detection.
Fully integrated AFE, ADC, LED drivers, and timing core
Enables ambient light rejection capability without the need
for photodiode optical filters
Three 370 mA LED peak current drivers
Flexible, multiple, short LED pulses per optical sample
20-bit burst accumulator enabling 20 bits per sample period
On-board sample to sample accumulator, enabling up to
27 bits per data read
Low power operation
The analog front end (AFE) features rejection of signal offset and
corruption due to modulated interference commonly caused by
ambient light without the need for optical filters or dc cancellation
circuitry that requires external control.
SPI, I2C interface, and 1.8 V analog/digital core
Flexible sampling frequency ranging from 0.122 Hz to 2700 Hz
FIFO data operation
Qualified for automotive applications
Couple the ADPD1080/ADPD1081 with a low capacitance
photodiode of <100 pF for optimal performance. The ADPD1080/
ADPD1081 can be used with any LED. The ADPD1080 is available
in a 16-ball, 2.46 mm × 1.4 mm WLCSP and a 28-lead, 4 mm ×
4 mm LFCSP. The SPI only version, ADPD1081, is available in
a 17-ball, 2.46 mm × 1.4 mm WLCSP.
APPLICATIONS
Wearable health and fitness monitors
Clinical measurements, for example, SpO2
Industrial monitoring
Background light measurements
Rev. C
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