AS7030B datasheet(64/129 Pages) AMSCO

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AS7030B

Functional Description

Datasheet

• PUBLIC

DS000716

• v1-00 • 2020-Jun-10

128

│ 63

High Pass Filter

Two optional high pass filters can be used to remove unwanted DC-components from the signal and

allows further amplification. In order to guarantee fast settling times of the filter, four cutoff frequencies

can be chosen.

Gain Stage

Two optional gain stage can be used to amplify the signal after the DC-component has been removed.

Figure 75:

Optical Signal Conditioning Signal Path (25 Hz LED sampling rate example)

The LED that is periodically turned ON and OFF, samples the cardio-vascular pulse wave. The

photodiode measures the reflected light that is modulated by the LED sampling frequency (25 Hz in

the examples Figure 75). Unwanted light like red/IR ambient light or glass reflected LED light is not

modulated. The signal can be sent to the Pre-filter Block where an anti-aliasing filter removes the high

frequency noise, followed by a high pass filter that removes the low frequency noise and unwanted dc

light. After the synchronous demodulator demodulates the signal it is filtered and amplified.

AS7030B Datasheet(PDF) 64 Page - ams AG