GENERAL DESCRIPTION
The ADPD6000 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 four 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 electrocardiography (ECG) signal acquisition is designed to
support low noise, diagnostic level measurement in the presence
of a variety of interferers. The ECG signal chain has a number
of complementary features supporting ECG measurement, such as
driven reference for common-mode rejection and lead off detection
to identify a fallen electrode.
The body impedance analysis (BIA) signal chain is designed for
body impedance measurement with a configurable excitation path
and measurement path. A 12-bit digital-to-analog (DAC) is used
in the excitation path to generate the sinusoid wave and high
precision measurement, with configurable filters used to measure
the body response of the stimulus.
The data output and functional configuration use a serial port interface
(SPI) on the ADPD6000. The control circuitry includes flexible
LED signaling and synchronous detection, digital filters, digital wave
generators, and configurable filters.
The ADPD6000 is available in a 2.6 mm × 2.6 mm, 0.4 mm pitch,
36-ball wafer level chip scale package (WLCSP).

FEATURES
► Optical channel
► 4 input channels with multiple operation modes for various
sensor measurements
► Dual channel processing with simultaneous sampling
► 12 programmable time slots for synchronized sensor measurements
► Flexible input multiplexing to support single-ended sensor
measurements
► 4 LED drivers, 2 of which can be driven simultaneously
► Flexible sampling rate from 0.004 Hz to 9 kHz using internal
oscillators
► SNR of transmit and receive signal chain: 117 dB (with off-chip
filtering)
► AC ambient light rejection: 78 dB up to 100 Hz
► 400 mA total LED peak drive current
► Individual ambient light rejection 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
► ECG channel
► 0.75 μV rms RTI noise at diagnostic filter bandwidth (150 Hz)
► High input impedance: 3 GΩ
► Accepts up to 1.2 V of dc differential input range
► Common-mode rejection ratio: 116 dB
► Two-electrode and three-electrode configurations
► AC lead off detection and dc lead off detection
► BIA channel
► Low power, high accuracy excitation path
► Configurable output frequency up to 250 kHz
► Sine wave excitation with a 12-bit DAC
► High accuracy with large imbalance contact impedance
► Configurable receive filters with low noise design
► Complex impedance measurement engine
► Supports both external calibration and internal calibration
► SPI communications supported
► 640-byte FIFO

APPLICATIONS
► Wearable health and fitness monitors: heart rate, heart rate
variability, SpO2, body impedance analysis, hydration, cuffless
noninvasive blood pressure
► Home patient monitoring
► Industrial monitoring: particle and aerosol, gas, and conductivity
detection