SX9331EVKA datasheet(14/48 Pages) SEMTECH

Part #	SX9331EVKA

Description	PerSe Connect, High Performance Small 5-ch. Capacitive Sensor

PDF	48 Pages

Scroll/Zoom	100%

Manufacturer	SEMTECH [Semtech Corporation]

Direct Link	http://www.semtech.com

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14 / 48 page

SX9331

Final Datasheet

April 21, 2023

www.semtech.com

14 of 48

Rev. 2

Proprietary & Confidential

Semtech

3.3.2.AFE Block-Diagram

Shield

Sensor

C-to-V

Analog Front-End (AFE)

Finger, palm,

face, etc

Shield

Control

ADC

PROXADC

Offset

Compensation

PROXOFFSET

CSIOx

Figure 8: Analog Front-End Block Diagram

3.3.3.Capacitance-to-Voltage Conversion (C-to-V)

The sensitivity of the interface is determined mainly by AGAIN parameter.

FREQ defines the operating frequency of the interface.

3.3.4.Shield Control

When not being measured, any CSIOx pin can be used as a shield.

3.3.5.Offset Compensation

Offset compensation consists of performing a one-time measurement of CEnv and subtracting it from the total

capacitance CSensor in order to feed the ADC with the closest contribution of CUser only.

ADC

Offset

Compensation

PROXOFFSET

CSensor

~CUser

Figure 9: Offset Compensation Block Diagram

SX9331EVKA Datasheet(PDF) 14 Page - Semtech Corporation