1 Features

• Supports signal acquisition of up to 24 phases
• Flexible allocation of 8 LED, 4 PD in each phase
• Simultaneous signal acquisition from different sensors at different data rates
• Accurate, continuous heart-rate monitoring:
  • System SNR up to 108-dB at 16 μA PD current
  • Low Current for Continuous Operation on a Wearable Device with a Typical Value: 15 μA for an LED, 20 μA for the Receiver
• Transmitter:
  • Supports common anode LED configuration
  • 8-Bit programmable LED current with range adjustable from 25 mA to 250 mA
  • Mode to fire two LEDs in parallel with independent per-phase current control
  • Programmable LED on-time per-phase
  • Simultaneous support of 8 LEDs for SpO₂, HRM, or multi-wavelength HRM
• Receiver:
  • Supports 4 Time-Multiplexed Photodiode Inputs
  • 2 parallel receivers (two sets of TIA/filter)
  • Individual Ambient Offset Subtraction DAC at each TIA Input with 8-bit per-phase control and range adjustable up to 255-μA
  • Individual LED Offset Subtraction DAC at each TIA input with 5-bit per-phase control and 15.5-µA range
  • Close to 100 dB ambient rejection up to 10 Hz
  • Noise filtering with programmable bandwidth
  • Transimpedance Gain: 3.7 kΩ to 1 MΩ
• Supports external clock and internal oscillator modes
• Option to acquire data synchronized with a system master clock
• Automatic cancellation of DC from ambient, LED
• FIFO with 128-sample depth
• SPI interface
• 2.6-mm × 2.1-mm DSBGA, 0.4-mm pitch
• Supplies: Rx: 1.7 V-1.9 V (LDO bypass); 1.9 V-3.6 V (LDO enabled), Tx: 3 V-5.5 V, IO: 1.7-3.6 V