Optimized Pulse-Oximeter and Heart Rate AFE for Wearable Health

 

Part Number	Replacement	Explanation

Description

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The MAX30112 is a complete optical pulse oximetry and heart rate detection integrated analog front-end. The MAX30112 has a high-resolution, optical readout signal-processing channel with built-in ambient light cancellation, as well as high-current LED driver DACs, to form a complete optical readout signal chain. With external LED(s) and photo diode(s), the MAX30112 offers the lowest power, highest performance heart rate detection solution for wrist applications.

The MAX30112 operates on a 1.8V main supply voltage, with a separate 3.1V to 5.25V LED driver power supply. The device supports a standard I²C compatible interface, as well as shutdown modes through the software with near-zero standby current, allowing the power rails to remain powered at all times.

MAX30112: Simplified Block Diagram Enlarge+

Key Features

• Reflective or Transmissive Heart Rate, Heart Rate Variability, or SpO₂ Monitoring
• Transmit Section
  • Two 8-bit LED Current DACs
  • Four Current Ranges 50mA, 100mA, 150mA, 200mA
  • Low Noise Current Sources for High Peak Transmit to Receive Dynamic Range
  • Low 160mV Dropout to Support Direct Drive From Rechargeable Li Battery
  • High Output Impedance and High Supply Rejection to Support Unregulated Supply or Direct Drive From Boost Switcher Supply
• Receive Section
  • 19-bit Optical ADC Path to Support the Lowest Perfusions Situations
  • Low 25pA-RMS Input Referred Noise to Minimize LED Power Under Most Conditions
  • High Ambient Light Input Range of 200μA and to Support Extraction of HRM Signal in the Most Adverse Lighting Conditions
  • Built-in Front And Back End Ambient Light Cancellation, Improving Rejection and Eliminating System Complexity of Dealing with Ambient Light
  • Short Exposure Pulse Widths of 52μs, 104μs, 206μs, 417μs for Efficient Uses of LED Light
  • Multiple Sample Rate Options from 20sps to 3.2ksps
• Ultra-Low-Power Operation for Mobile and Body-Wearable Device
  • Dynamic Power Down Modes to 100sps for Low-Power Consumption
  • Full AFE Power Consumption of Less Than 25μA (typ) at 25sps
  • Large 32 Sample FIFO to Support Batch Processing in the Microcontroller
  • Variety of System Monitors Mappable to Interrupts to Off-Load System Monitoring Functions From the Microcontroller
  • Low Shutdown Current = 1.4μA (typ)
• I²C interface
• Supports a Single 1.8V Supply with Separate 3.1V to 5.25V LED Supply
• Miniature 2.8mm x 2.0mm, 6x4, 0.4mm Ball Pitch WLP Package
• -40°C to +85°C Operating Temperature Range

Applications/Uses

• Fitness Wearable Devices
• In-Ear Wearable Devices
• SpO₂ Monitoring Devices
• Wrist-Worn Wearable Devices