Packaging information
| Package | Pins DSBGA (YZ) | 30 |
| Operating temperature range (°C) -40 to 85 |
| Package qty | Carrier 250 | SMALL T&R |
Features for the AFE44I30
- Supports signal acquisition of up to 24 phases
- Flexible allocation of 6 LED, 4 PD in each phase
- Simultaneous signal acquisition from different sensors at different data rates
- Accurate, continuous heart-rate
monitoring:
- System SNR up to 108-dB at 16 µA PD current
- Low current for continuous operation on a wearable device with a typical value: 15 µA for an LED, 20 µA for the receiver
- Transmitter:
- Supports common anode LED configuration
- 8-Bit programmable LED current with range adjustable from 25 mA to 250 mA
- Mode to fire two LEDs in parallel with independent per-phase current control
- Programmable LED on-time per-phase
- Simultaneous support of 6 LEDs for SpO2, HRM, or multi-wavelength HRM
- Receiver:
- Supports 4 time-multiplexed photodiode inputs
- 2 parallel receivers (two sets of TIA/filter)
- Individual ambient offset subtraction DAC at each TIA Input with 8-bit per-phase control and range adjustable up to 255-µA
- Individual LED offset subtraction DAC at each TIA input with 5-bit per-phase control and 15.5-µA range
- Close to 100 dB ambient rejection up to 10 Hz
- Noise filtering with programmable bandwidth
- Transimpedance Gain: 3.7 kΩ to 1 MΩ
- Supports external clock and internal oscillator modes
- Option to acquire data synchronized with a system master clock
- Automatic cancellation of DC from ambient, LED
- FIFO with 128-sample depth
- I2C interface
- 2.6-mm × 2.1-mm DSBGA, 0.4-mm pitch
- Supplies: Rx: 1.7 V-1.9 V (LDO bypass); 1.9 V-3.6 V (LDO enabled), Tx: 3 V-5.5 V, IO: 1.7-3.6 V
Description for the AFE44I30
The AFE44I30 is an analog front-end for optical bio-sensing applications, such as heart-rate monitoring (HRM) and saturation of peripheral capillary oxygen (SpO2). The device supports up to six switching light-emitting diodes (LEDs) and up to four photodiodes. Up to 24 signal phases can be defined and the signal can be acquired from each phase in a synchronized manner. The current from the photodiode is converted into voltage by the transimpedance amplifier (TIA) and digitized using an analog-to-digital converter (ADC). The ADC code can be stored in a 128-sample First in, First out (FIFO) block. The FIFO can be read out using a I2C interface. The AFE also has a fully-integrated LED driver with an 8-bit current control. The device has a high dynamic range transmit-and-receive circuitry that helps with the sensing of very small signal levels.