The AFE4403 is a fully-integrated analog front-end (AFE) ideally suited for pulse oximeter applications. The device consists of a low-noise receiver channel with an integrated analog-to-digital converter (ADC), an LED transmit section, and diagnostics for sensor and LED fault detection. The device is a very configurable timing controller. This flexibility enables the user to have complete control of the device timing characteristics. To ease clocking requirements and provide a low-jitter clock to the AFE4403, an oscillator is also integrated that functions from an external crystal. The device communicates to an external microcontroller or host processor using an SPI™ interface.
●The device is a complete AFE solution packaged in a single, compact DSBGA-36 (3.07 mm × 3.07 mm × 0.5 mm) and is specified over the operating temperature range of –20°C to 70°C.
● Fully-Integrated AFE for Pulse Oximeter and Heart Rate Monitoring Applications:
● Transmit:
● Integrated Dual LED Driver
●(H-Bridge or Common Anode)
● Option for a Third LED Support for Optimized SPO2, HRM, or Multi-Wavelength HRM
● Up to 110-dB Dynamic Range
● LED Current:
● Programmable to 100 mA with 8-Bit Current Resolution
● 30 µA + Average LED Current
● Programmable LED On-Time
● Independent LED2 and LED1 Current Reference
● Receive Channel with High Dynamic Range:
● 22-Bit Output in Twos Complement Format
● Up to 105-dB Dynamic Range
● Low Power: < 650 µA
● Dynamic Power-Down Mode to Reduce Current to 300 µA
● Adaptable to a Very Wide Range of Signal Amplitudes:
● Total Programmable Gain: 10 kΩ to 4 MΩ
● Integrated Digital Ambient Estimation and Subtraction
● Flexible Clocking by External Clock or Crystal:
● Pulse Frequency: 62.5 SPS to 2000 SPS
● Flexible Pulse sequencing and Timing Control
● Input Clock Range: 4 MHz (Min) to 60 MHz (Max)
● Integrated Fault Diagnostics:
● Photodiode and LED Open and
●Short Detection
● Supplies:
● Rx = 2.0 V to 3.6 V
● Tx = 3.0 V to 5.25 V
● Package: Compact DSBGA-36
●(3.07 mm × 3.07 mm × 0.5 mm)
● Specified Temperature Range: –20°C to 70°C
