GENERAL DESCRIPTION

The ADPD7008 is a highly integrated analog front end (AFE)

designed for measuring various vital signals.

The optical channel is designed as an optical transceiver, stimulating

up to eight light emitting diodes (LEDs) and measuring the

return signal on up to four separate current inputs. The signal chain

rejects signal offsets and corruption from asynchronous modulated

interference, typically from ambient light, eliminating the need for

optical filters or externally controlled DC cancellation circuitry.

The data output and functional configuration use a serial port interface

(SPI) on the ADPD7008. The control circuitry includes flexible

LED signaling and synchronous detection, digital filters, digital wave

generators, and configurable filters.

The ADPD7008 is available in a 2.795 mm × 2.560 mm, 0.40 mm

pitch, 36-ball WLCSP.

FEATURES

► Optical channel

► 4 input channels with multiple operation modes for various

sensor measurements

► 4-channel processing with simultaneous sampling

► 12 programmable time slots for synchronized sensor measurements

► Flexible input multiplexing to support single-ended sensor

measurements

► 8 LED drivers, 2 of which can be driven simultaneously

► Flexible sampling rate from 0.004 Hz to 9 kHz using internal

oscillators

► AC ambient light rejection: 78 dB up to 100 Hz

► 400 mA total LED peak drive current

► Individual ambient cancellation DAC at TIA input with 9-bit

control up to 300 μA

► Individual LED DC cancellation DAC at TIA input with 7-bit

control up to 190 μA

► SPI communications supported

► 704-byte FIFO

APPLICATIONS

► Wearable health and fitness monitors: heart rate, heart rate

variability, and saturation level of pulse oxygen

► Clinical patient monitors: small bed side patient, home portable

patient, and small remote patient

► Industrial monitoring: particle, aerosol, and gas detection