AFE4400 是一款非常适合于脉冲血氧仪应用的完全集成模拟前端 (AFE)。 此器件包含一个具有集成模数转换器 (ADC) 的低噪声接收器通道、一个 LED 发射部件和针对传感器以及 LED 故障检测的诊断功能。 此器件是一款可配置定时控制器。 这个灵活性使得用户能够完全控制器件定时特性。 为了简化计时要求并为 AFE4400 提供一个低抖动时钟，还集成了一个由外部晶振供频的振荡器。 此器件使用一个 SPI 接口与外部微控制器或主机处理器通信。-The AFE4400 is a fully-integrated analog front-end

(AFE) ideally suited for pulse oximeter applications. (H-Bridge, Push, or Pull)

The device consists of a low-noise receiver channel

– Dynamic Range: 95 dB with an integrated analog-to-digital converter (ADC),

– LED Current: an LED transmit section, and diagnostics for sensor

– Programmable to 50 mA with 8-Bit Current and LED fault detection. The device is a very

Resolution configurable timing controller. This flexibility enables

the user to have complete control of the device timing

– Low Power: characteristics. To ease clocking requirements and

– 100 μA+ Average LED Current provide a low-jitter clock to the AFE4400, an oscillator

– Programmable LED On-Time is also integrated that functions　an external

crystal. The device communicates to an external

– Independent LED2 and LED1 Current microcontroller or host processor using an SPI™　Reference interface.