The AFE4410 is an analog front-end for optical biosensing applications, such as heart-rate monitoring (HRM). The device supports up to four switching light-emitting diodes (LEDs) and up to three photodiodes (PDs). 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 is stored in a 128-sample first in, first-out block (FIFO) with programmable depth. The FIFO can be read out using either an I2C interface or a serial peripheral interface (SPI). The AFE also has a fully integrated LED driver with 8-bit current control. The device has high dynamic range transmit-and-receive circuitry offering a dynamic range of up to 100 dB that enables accurate heart-rate sensing. The AFE achieves extremely low current levels by operating an ultralow power (ULP) mode set by using the ENABLE_ULP register bit.
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|Part number||Order||Number of input channels||Resolution (Bits)||Interface||Number of LEDs||Features||Operating temperature range (C)||Package Group||Package size: mm2:W x L (PKG)||Approx. price (US$)|
|4||Optical biosensing||-20 to 70||2.65 | 1ku|
||1||22||SPI||3||Optical biosensing||-20 to 70||DSBGA | 36||See datasheet (DSBGA)||3.25 | 1ku|
||1||24||I2C||3||Optical biosensing||-20 to 70||DSBGA | 15||See datasheet (DSBGA)||2.28 | 1ku|
|AFE4405||Samples not available||2||24||
|3||Optical biosensing||-20 to 70||2.50 | 1ku|
|AFE4420||Samples not available||4||24||I2C||4||Optical Biosensing||-40 to 85||4.10 | 1ku|
||1||22||Serial SPI||2||Optical biosensing||-40 to 85||VQFN | 40||40VQFN: 36 mm2: 6 x 6 (VQFN | 40)||7.95 | 1ku|
|AFE4900||Samples not available||3||24||
|4||Optical biosensing||-20 to 70||2.75 | 1ku|