Oxygen Saturation (SpO₂) Measurement

The ADPD4100/ADPD4101 operate as a complete multimodal sensor front end, stimulating up to eight light emitting diodes (LEDs) and measuring the return signal on up to eight separate current inputs. Twelve time slots are available, enabling 12 separate measurements per sampling period.

The data output and functional configuration utilize an I²C interface on the ADPD4101 or a serial port interface (SPI) on the ADPD4100. The control circuitry includes flexible LED signaling and synchronous detection. The devices use a 1.8 V analog core and 1.8 V/3.3 V compatible digital input/output (I/O).

The analog front end (AFE) 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. Multiple operating modes are provided, enabling the ADPD4100/ADPD4101 to be a sensor hub for synchronous measurements of photodiodes, biopotential electrodes, resistance, capacitance, and temperature sensors. The multiple operation modes accommodate various sensor measurements, including, but not limited to, photoplethysmography (PPG), electrocardiography (ECG), electrodermal activity (EDA), impedance, capacitance, temperature, gas detection, smoke detection, and aerosol detection for various healthcare, industrial, and consumer applications.

The ADPD4100/ADPD4101 are available in a 3.11 mm × 2.14 mm, 0.4 mm pitch, 33-ball WLCSP and 35-ball WLCSP

Applications

• Wearable health and fitness monitors: heart rate monitors (HRMs), heart rate variability (HRV), stress, blood pressure estimation, SpO2, hydration, body composition
• Industrial monitoring: CO, CO2, smoke, and aerosol detection
• Home patient monitoring

The ADPD4100/ADPD4101 operate as a complete multimodal sensor front end, stimulating up to eight light emitting diodes (LEDs) and measuring the return signal on up to eight separate current inputs. Twelve time slots are available, enabling 12 separate measurements per sampling period.

The data output and functional configuration utilize an I²C interface on the ADPD4101 or a serial port interface (SPI) on the ADPD4100. The control circuitry includes flexible LED signaling and synchronous detection. The devices use a 1.8 V analog core and 1.8 V/3.3 V compatible digital input/output (I/O).

The analog front end (AFE) 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. Multiple operating modes are provided, enabling the ADPD4100/ADPD4101 to be a sensor hub for synchronous measurements of photodiodes, biopotential electrodes, resistance, capacitance, and temperature sensors. The multiple operation modes accommodate various sensor measurements, including, but not limited to, photoplethysmography (PPG), electrocardiography (ECG), electrodermal activity (EDA), impedance, capacitance, temperature, gas detection, smoke detection, and aerosol detection for various healthcare, industrial, and consumer applications.

The ADPD4100/ADPD4101 are available in a 3.11 mm × 2.14 mm, 0.4 mm pitch, 33-ball WLCSP and 35-ball WLCSP

Applications

• Wearable health and fitness monitors: heart rate monitors (HRMs), heart rate variability (HRV), stress, blood pressure estimation, SpO2, hydration, body composition
• Industrial monitoring: CO, CO2, smoke, and aerosol detection
• Home patient monitoring

The ADPD105/ADPD106/ADPD107 are highly efficient, photometric front ends, each with an integrated 14-bit analog-to-digital converter (ADC) and a 20-bit burst accumulator that works with flexible light emitting diode (LED) drivers. The accumulator is designed to stimulate an LED and measure the corresponding optical return signal. The data output and functional configuration occur over a 1.8 V I²C interface on the ADPD105 or SPI on the ADPD106 and ADPD107. The control circuitry includes flexible LED signaling and synchronous detection.

The analog front end (AFE) features best-in-class rejection of signal offset and corruption due to modulated interference commonly caused by ambient light.

Couple the ADPD105/ADPD106/ADPD107 with a low capacitance photodiode of <100 pF for optimal performance. The ADPD105/ADPD106/ADPD107 can be used with any LED. The ADPD105 is available in a 2.46 mm × 1.4 mm WLCSP and a 4 mm × 4 mm LFCSP. The SPI only versions, ADPD106 and ADPD107, are available in a 2.46 mm × 1.4 mm WLCSP.

Applications

• Wearable health and fitness monitors
• Clinical measurements, for example, SpO₂
• Industrial monitoring
• Background light measurements

The ADPD105/ADPD106/ADPD107 are highly efficient, photometric front ends, each with an integrated 14-bit analogto-digital converter (ADC) and a 20-bit burst accumulator that works with flexible light emitting diode (LED) drivers. The accumulator is designed to stimulate an LED and measure the corresponding optical return signal. The data output and functional configuration occur over a 1.8 V I²C interface on the ADPD105 or SPI on the ADPD106 and ADPD107. The control circuitry includes flexible LED signaling and synchronous detection.

The analog front end (AFE) features best-in-class rejection of signal offset and corruption due to modulated interference commonly caused by ambient light.

Couple the ADPD105/ADPD106/ADPD107 with a low capacitance photodiode of <100 pF for optimal performance. The ADPD105/ADPD106/ADPD107 can be used with any LED. The ADPD105 is available in a 2.46 mm × 1.4 mm WLCSP and a 4 mm × 4 mm LFCSP. The SPI only versions, ADPD106 and ADPD107, are available in a 2.46 mm × 1.4 mm WLCSP.

Applications

• Wearable health and fitness monitors
• Clinical measurements, for example, SpO₂
• Industrial monitoring
• Background light measurements

The ADPD105/ADPD106/ADPD107 are highly efficient, photometric front ends, each with an integrated 14-bit analog-to-digital converter (ADC) and a 20-bit burst accumulator that works with flexible light emitting diode (LED) drivers. The accumulator is designed to stimulate an LED and measure the corresponding optical return signal. The data output and functional configuration occur over a 1.8 V I²C interface on the ADPD105 or SPI on the ADPD106 and ADPD107. The control circuitry includes flexible LED signaling and synchronous detection.

The analog front end (AFE) features best-in-class rejection of signal offset and corruption due to modulated interference commonly caused by ambient light.

Couple the ADPD105/ADPD106/ADPD107 with a low capacitance photodiode of <100 pF for optimal performance. The ADPD105/ADPD106/ADPD107 can be used with any LED. The ADPD105 is available in a 2.46 mm × 1.4 mm WLCSP and a 4 mm × 4 mm LFCSP. The SPI only versions, ADPD106 and ADPD107, are available in a 2.46 mm × 1.4 mm WLCSP.

Applications

• Wearable health and fitness monitors
• Clinical measurements, for example, SpO₂
• Industrial monitoring
• Background light measurements

The ADPD144RI is a highly integrated, photometric front end optimized for photoplethysmography (PPG) detection of blood oxygenation (SpO2) by synchronous detection in red and infrared wavelengths. Synchronous measurement allows rejection of both dc and ac ambient light interference with extremely low power consumption.

The module combines highly efficient, light emitting diode (LED) emitters and a sensitive 4-channel, deep diffusion photodiode (PD1 to PD4) with a custom application specific integrated circuit (ASIC) in a compact package that provides optical isolation between the integrated LED emitters and the detection photodiodes to improve through tissue, signal-tonoise ratio (SNR).

The ASIC consists of a 4-channel analog front end (AFE) with two independently configurable datapaths with separate gain and filter settings, a 14-bit analog-to-digital converter (ADC) with a burst accumulator, two flexible, independently configurable, LED drivers, and a digital control block. The digital control block provides AFE and LED timing, signal processing, and communication. Data output and functional configuration occur over a 1.8 V I²C interface.

Applications

• Optical heart rate monitoring
• Reflective SpO2 measurement