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