AFE4950 Series

Ultra-small integrated AFE for wearable optical heart-rate monitoring and SpO2

Catalog

Ultra-small integrated AFE for wearable optical heart-rate monitoring and SpO2

Part	Supplier Device Package	Mounting Type	Number of Channels	Voltage - Supply, Digital [Min]	Voltage - Supply, Digital [Max]
Texas Instruments AFE4950YBGR	36-DSBGA (2.63x2.46)	Surface Mount	1	1.7 V 1.9 V 3 V	1.9 V 3.6 V 5.5 V
Texas Instruments AFE4950YBGT	36-DSBGA (2.63x2.46)	Surface Mount	1	1.7 V 1.9 V 3 V	1.9 V 3.6 V 5.5 V

Catalog

Ultra-small integrated AFE for wearable optical heart-rate monitoring and SpO2

Key Features

• Supports simultaneous and synchronized acquisition of up to 24 PPG and a single-lead ECG signal.Flexible allocation of 8 LED, 4 PD in each phaseECG signal chain:1-lead ECG signal acquisition up to 2 kHzRLD output to drive a third electrodeInput noise : 0.7 µV-rmsSupports up to ±0.65 V differential DC offset and +/-0.55 V common mode rangeProgrammable INA gain: 11, 21High-pass filter with quick saturation recoveryIntegrated 300 Hz anti-aliasing low pass filterAC, DC lead-off detect: 2.9 nA to 92.5 nALow power continuous lead-on detectionImpedance signal chainContinuous low-power monitoring of impedance between 2 electrodes7 MΩ range300 Ω noise on 620 kΩPPG Transmitter:8-Bit Programmable LED Current with range adjustable from 25 mA to 250 mAMode to fire two LEDs in parallelSupport of 8 LEDs in Common Anode configuration for SpO2, Multi-Wavelength HRMPPG Receiver:2 parallel receivers (two sets of TIA/ filter)Supports 4 Time-Multiplexed Photodiode Inputs to each Receiver8-bit Ambient Offset subtraction at each TIA input with 256 µA range8-bit LED Offset Subtraction DAC with 64 µA rangeAutomatic ambient cancellation and dynamic LED DC cancellation at TIA inputAmbient rejection close to 100 dB up to 10 HzNoise filtering with programmable bandwidthTrans-impedance Gain: 3.7 kΩ to 1 MΩAccurate, Continuous Heart-Rate Monitoring:System SNR up to 109-dB at 16 µA PD currentLow Current for Continuous Operation on a Wearable Device with a Typical Value: 15-µA for an LED, 20-µA for the ReceiverExternal clock and internal oscillator modesAcquire data synchronized with system master clockFIFO with 256-sample DepthSPI, I2C interfaces: Selectable by pin2.6-mm × 2.5-mm DSBGA, 0.4-mm PitchSupplies: Rx:1.7-1.9V (LDO Bypass); 1.9-3.6V (LDO Enabled), Tx:3-5.5V, IO:1.7-RX_SUPSupports simultaneous and synchronized acquisition of up to 24 PPG and a single-lead ECG signal.Flexible allocation of 8 LED, 4 PD in each phaseECG signal chain:1-lead ECG signal acquisition up to 2 kHzRLD output to drive a third electrodeInput noise : 0.7 µV-rmsSupports up to ±0.65 V differential DC offset and +/-0.55 V common mode rangeProgrammable INA gain: 11, 21High-pass filter with quick saturation recoveryIntegrated 300 Hz anti-aliasing low pass filterAC, DC lead-off detect: 2.9 nA to 92.5 nALow power continuous lead-on detectionImpedance signal chainContinuous low-power monitoring of impedance between 2 electrodes7 MΩ range300 Ω noise on 620 kΩPPG Transmitter:8-Bit Programmable LED Current with range adjustable from 25 mA to 250 mAMode to fire two LEDs in parallelSupport of 8 LEDs in Common Anode configuration for SpO2, Multi-Wavelength HRMPPG Receiver:2 parallel receivers (two sets of TIA/ filter)Supports 4 Time-Multiplexed Photodiode Inputs to each Receiver8-bit Ambient Offset subtraction at each TIA input with 256 µA range8-bit LED Offset Subtraction DAC with 64 µA rangeAutomatic ambient cancellation and dynamic LED DC cancellation at TIA inputAmbient rejection close to 100 dB up to 10 HzNoise filtering with programmable bandwidthTrans-impedance Gain: 3.7 kΩ to 1 MΩAccurate, Continuous Heart-Rate Monitoring:System SNR up to 109-dB at 16 µA PD currentLow Current for Continuous Operation on a Wearable Device with a Typical Value: 15-µA for an LED, 20-µA for the ReceiverExternal clock and internal oscillator modesAcquire data synchronized with system master clockFIFO with 256-sample DepthSPI, I2C interfaces: Selectable by pin2.6-mm × 2.5-mm DSBGA, 0.4-mm PitchSupplies: Rx:1.7-1.9V (LDO Bypass); 1.9-3.6V (LDO Enabled), Tx:3-5.5V, IO:1.7-RX_SUP

Description

The AFE4950 device is an analog front-end (AFE) for synchronized signal acquisition of PPG and ECG signals. The device can also be used for optical bio-sensing applications, such as heart-rate monitoring (HRM) and saturation of peripheral capillary oxygen (SpO2). The ECG signal chain supports 2- and 3-electrode configurations and has an integrated Right leg drive (RLD) buffer. The ECG signal chain can also be used to do a continuous, low-power monitoring of the impedance between pair of electrodes. The AFE4950 device is an analog front-end (AFE) for synchronized signal acquisition of PPG and ECG signals. The device can also be used for optical bio-sensing applications, such as heart-rate monitoring (HRM) and saturation of peripheral capillary oxygen (SpO2). The ECG signal chain supports 2- and 3-electrode configurations and has an integrated Right leg drive (RLD) buffer. The ECG signal chain can also be used to do a continuous, low-power monitoring of the impedance between pair of electrodes.