TI AFE4400RHAR

The AFE4400 is a fully integrated AFE designed for pulse oximeter applications. It includes a low-noise receiver channel with an integrated ADC, an LED transmitter, and diagnostic functions for sensor and LED fault detection. A configurable timing controller provides users with full control over device timing characteristics. An integrated oscillator driven by an external crystal simplifies timing requirements and delivers a low-jitter clock. Communication with an external microcontroller or host processor is achieved via an SPI interface. The device is a complete AFE solution in a single, compact VQFN-40 package (6mm × 6mm), rated for an operating temperature range of 0°C to 70°C.

• Fully integrated analog front-end for pulse oximeter applications: flexible pulse sequencing and timing control
• Integrated LED driver (H-bridge, push-pull)
• Dynamic range: 95dB
• LED current: programmable up to 50mA with 8-bit current resolution
• Low power: 100μA + average LED current
• Programmable LED on-time
• Independent LED2 and LED1 current references
• 13 noise-free bits
• Low power: less than 670μA at 3.3V supply
• Integrated digital ambient estimation and subtraction
• Flexible receive sampling time
• Flexible transimpedance amplifier with programmable LED settings
• Photodiode and LED open/short detection, cable connect and disconnect detection
• Rx = 2.0V to 3.6V, Tx = 3.0V to 5.25V
• Package: compact ultra-thin VQFN-40 (6mm×6mm)
• Rated temperature range: 0°C to 70°C

• Low-cost medical pulse oximeter applications
• Optical heart rate monitor (HRM)
• Industrial optical measurement applications