Maxim公司的MAX86140/MAX86141是超低功耗全集成光學數據采集系統,發送端MAX86140/MAX86141有三個可編程大電流LED驅動器,可驅動多達六個LED;在接收端,MAX86140有單個光學讀出通路,而MAX86141有兩個能同時工作的光學讀出通路.器件的低噪音信號調理模擬前端(AFE)包產到戶有19位ADC,業界一流環境光消除(ALC)電路,警戒圍欄檢測和替代算法.動態范圍> 90dB,工作電壓1.8V,主要用在可穿戴設備,氧飽和(SpO2)以及肌肉氧飽和(SmO2和StO2).本文介紹了MAX86140/MAX86141主要優勢和特性,框圖和應用電路,以及MAX86140/MAX86141評估系統主要特性,框圖,電路圖,材料清單和PCB設計圖.

The MAX86140/MAX86141 are ultra-low-power, com-pletely integrated, optical data acquisition systems. On the transmitter side, the MAX86140/MAX86141 have three programmable high-current LED drivers that can be configured to drive up to six LEDs. With two MAX86140/MAX86141 devices working in master-slave mode, the LED drivers can drive up to twelve LEDs. On the receiver side, MAX86140 consists of a single optical readout channels, while the MAX86141 has two opti-cal readout channels that can operate simultaneously. The devices have low-noise signal conditioning analog front-end (AFE) including 19-bit ADC, an industry-lead ambient light cancellation (ALC) circuit, and a picket fence detect and replace algorithm. Due to the low power consumption, compact size, easy/flexible-to-use and industry-lead ambient light rejection capability of MAX86140/MAX86141, the devices are ideal for a wide variety of optical-sensing applications, such as pulse oximetry and heart rate detection.

The MAX86140/MAX86141 operate on a 1.8V main supply voltage and a 3.1~5.5V LED driver supply voltage. Both devices support a standard SPI compatible interface and fully autonomous operation. Each device has a large 128-word built-in FIFO. The MAX86140/MAX86141 is available in compact wafer-level package (WLP)(2.048 x 1.848mm) with 0.4mm ball pitch.

MAX86140/MAX86141主要優勢和特性:

Complete Single and Dual-Channel Optical Data Acquisition System
Built-in Algorithm Further Enhances Rejection of Fast Ambient Transients
Optimized Architecture for Transmissive and Reflective Heart Rate or SpO2 Monitoring
Low Dark Current Noise of < 50pA RMS (Sample to Sample Variance)
Lower Effective Dark Current Noise Achievable Through Multiple Sample Modes and On-Chip Averaging
High-Resolution, 19-Bit Charge Integrating ADC
Three Low-Noise, 8-Bit LED Current DACs
Excellent Dynamic Range>90dB in White Card Loop-Back Test (Sample-to-Sample Variance)
Dynamic Range Extendable to > 104dB for SpO2 and > 110dB for HRM with Multiple Sample Modes and On-Chip Averaging
Excellent Ambient Range and Rejection Capability> 100μA Ambient Photodetector Current
> 70dB Ambient Rejection at 120Hz
Ultra-Low-Power Operation for Body Wearable DevicesLow-Power Operation, Optical Readout Channel< 10μA (typ) at 25sps
Short Exposure Integration Period of 14.8μs, 29.4μs, 58.7μs, 117.3μs
Low Shutdown Current = 20μW (typ)
Built-in Algorithm Further Enhances Rejection of Fast Ambient Transients
Miniature 2.048 x 1.848mm, 5 x 4 0.4mm Ball Pitch WLP
-40 ℃ to +85℃ Operating Temperature Range

MAX86140/MAX86141應用:

Wearable Devices for Fitness, Wellness and Medical Applications
Optimized for Wrist, Finger, Ear, and Other Locations
Optimized Performance to DetectOptical Heart Rate
Oxygen Saturation (SpO2)
Muscle Oxygen Saturation (SmO2 and StO2)

圖1.MAX86140/MAX86141簡化框圖

圖2.MAX86140/MAX86141典型應用電路圖

MAX86140/MAX86141評估系統(EVSYS)

The MAX86140/MAX86141 Evaluation System (EVSYS) allows for the quick evaluation of the MAX86140 and MAX86141 optical AFE for applications at various sites on the body, particularly the wrist. Both MAX86140 and MAX86141 supports standard SPI compatible interface. MAX86140 consists of a single optical readout channels, while MAX86141 has two optical readout channels that operate simultaneously. The EVSYS allows flexible configurations to optimize measurement signal quality at minimal power consumption. The EVSYS helps the user quickly learn about how to configure and use the MAX86140 and MAX86141.

The EVSYS consists of three boards. MAX32620UC-BLEEK# is the main data acquisition board while MAX86140OSBEK# and MAX86141OSBEK# are the sensor daughter boards for MAX86140 and MAX86141 respectively. The EVSYS can be powered using the USB-C supply or LiPo Battery.

The EVSYS comes with a MAX86140ENP+/MAX86141-ENP+ in a 24-bump wafer-level package (WLP).

MAX86140/MAX86141評估系統主要特性:

Quick Evaluation of the MAX86140/MAX86141
Supports Optimization of Configurations
Facilitates Understanding MAX86140/MAX86141 Architecture and Solution Strategy
Real-time Monitoring
Data Logging Capabilities
On-Board Accelerometer
Bluetooth LE

圖3. MAX86140/MAX86141評估系統硬件建立圖(MAX86140 EVSYS傳感器PCB)

圖4. MAX86140/MAX86141評估系統硬件建立圖(MAX86141 EVSYS Micro PCB)

圖5. MAX86140/MAX86141評估系統硬件建立圖(MAX86141 EVSYS傳感器PCB)

圖6. MAX86140/MAX86141評估系統電路圖(1):MAX32620UCBLEEK#

圖7. MAX86140/MAX86141評估系統電路圖(2):MAX32620UCBLEEK#

圖8. MAX86140/MAX86141評估系統電路圖(3):MAX32620UCBLEEK#

圖9. MAX86140/MAX86141評估系統電路圖(4):MAX32620UCBLEEK#

圖10. MAX86140/MAX86141評估系統電路圖(5):MAX86140OSBEK#

圖11. MAX86140/MAX86141評估系統電路圖(6):MAX86141OSBEK#
MAX86140/MAX86141評估系統材料清單:MAX32620UCBLEEK#

圖12. MAX86140/MAX86141評估系統PCB設計圖(1): MAX32620UCBLEEK#頂層絲印

圖13. MAX86140/MAX86141評估系統PCB設計圖(2):
左:MAX32620UCBLEEK#頂層模板右: MAX32620UCBLEEK# L03 SIGS?

圖14. MAX86140/MAX86141評估系統PCB設計圖(3):
左:MAX32620UCBLEEK#頂層 右: MAX32620UCBLEEK# L04 SIGS

圖15. MAX86140/MAX86141評估系統PCB設計圖(4):
左:MAX32620UCBLEEK# L2 GND?右: MAX32620UCBLEEK# L05 SIGS

圖16. MAX86140/MAX86141評估系統PCB設計圖(5):
左:MAX32620UCBLEEK# L06 SIGS?右: MAX32620UCBLEEK#底層模板

圖17. MAX86140/MAX86141評估系統PCB設計圖(6):
左:MAX32620UCBLEEK# L07SIGS?右: MAX32620UCBLEEK#頂層助焊層

圖18. MAX86140/MAX86141評估系統PCB設計圖(7):
左:MAX32620UCBLEEK#底層 右: MAX32620UCBLEEK#底層助焊層

圖19. MAX86140/MAX86141評估系統PCB設計圖(8):
左:MAX32620UCBLEEK# L08 SIGS?右: MAX32620UCBLEEK# L10 SIGS

圖20. MAX86140/MAX86141評估系統PCB設計圖(9):
左:MAX32620UCBLEEK# L11 GND?右: MAX32620UCBLEEK# L09 SIGS

圖21. MAX86140/MAX86141評估系統PCB設計圖(10):
左:MAX86140OSBEK#頂層絲印 右: MAX86140OSBEK#頂層

圖22. MAX86140/MAX86141評估系統PCB設計圖(11):
左:MAX86140OSBEK#頂層模板 右: MAX86140OSBEK# L02 GND

圖23. MAX86140/MAX86141評估系統PCB設計圖(12):
左:MAX86140OSBEK# L03 GND?右: MAX86140OSBEK# L05 SIG

圖24. MAX86140/MAX86141評估系統PCB設計圖(13):
左:MAX86140OSBEK# L04 SIG?右: MAX86140OSBEK#底層

圖25. MAX86140/MAX86141評估系統PCB設計圖(14):
左:MAX86140OSBEK#底層模板 右: MAX86140OSBEK#頂層助焊層

圖26. MAX86140/MAX86141評估系統PCB設計圖(15):
左:MAX86140OSBEK#底層絲印 右: MAX86140OSBEK#底層助焊層

圖27. MAX86140/MAX86141評估系統PCB設計圖(16):
左:MAX86141OSBEK#頂層模板 右: MAX86141OSBEK# L02GND

圖28. MAX86140/MAX86141評估系統PCB設計圖(17):
左:MAX86141OSBEK#頂層 右: MAX86141OSBEK# L03 SIG

圖29. MAX86140/MAX86141評估系統PCB設計圖(18):
左:MAX86141OSBEK# L04 SIG?右: MAX86141OSBEK# L05 SIG

圖30. MAX86140/MAX86141評估系統PCB設計圖(19):
左:MAX86141OSBEK#頂層 右: MAX86141OSBEK#底層

圖31. MAX86140/MAX86141評估系統PCB設計圖(20):
左:MAX86141OSBEK#頂層助焊層 右: MAX86141OSBEK#頂層絲印

圖32. MAX86140/MAX86141評估系統PCB設計圖(21)