Maxim 可穿戴血氧和心率传感器解决方案-MAX86140/MAX86141结构详解

2018年02月09日 14:43 网络整理作者：用户评论（0）

关键字：传感器(752506)Maxim(87115)

Maxim 公司的MAX86140/MAX86141是超低功耗全集成光学数据采集系统,发送端MAX86140/MAX86141有三个可编程大电流LED驱动器,可驱动多达六个LED;在接收端,MAX86140有单个光学读出通路,而MAX86141有两个能同时工作的光学读出通路.器件的低噪音信号调理模拟前端(AFE)包产到户有19位ADC,业界一流环境光消除(ALC)电路,警戒围栏检测和替代算法.动态范围> 90dB,工作电压1.8V,主要用在可穿戴设备,氧饱和(SpO2)以及肌肉氧饱和(SmO2和StO2).本文介绍了MAX86140/MAX86141主要优势和特性,框图和应用电路,以及MAX86140/MAX86141评估系统主要特性,框图,电路图,材料清单和PCB设计图.

The MAX86140/MAX86141 are ultra-low-power, completely 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 optical 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主要优势和特性:

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应用:

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)