Cmsemicon SC7020 Series User Manual Download Page 8

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SC7020x

www.mcu.com.cn

Rev. 1.1

6.4 Sensitivity adjustment

The equivalent capacitance on the IC touch pad will affect the sensitivity. So the sensitivity adjustment

must according to the practical application on PCB. The SC7020x offers some methods for adjusting the

sensitivity outside.

1) By the touchpad size: Under other conditions are fixed. Using a larger touchpad size can increase

sensitivity.

Otherwise it can decrease sensitivity. But the touchpad size must use in the effective

scope.

2) By the panel thickness: Under other conditions are fixed. Using a thinner panel can increase

sensitivity. Otherwise it can decrease sensitivity.

3) By the value of Cs: Under other conditions are fixed. When the touchpad is not use the Cs to GND,

the sensitivity is most sensitive. When adding the value of Cs will reduce sensitivity in the useful

range

（

≦

50pF

）

Summary of Contents for SC7020 Series

Page 1: ...th trademarks of our company Our company preserve the rights to further elaborate on the improvements about product functions reliability and design in this manual However our company is not responsib...

Page 2: ...0201 SC70202 Pin Diagram 5 5 2 SC70205 Pin Diagram 6 6 FUNCTION DESCRIPTION 7 6 1 Output Mode and Pad Option 7 6 2 Maximum output time of key 7 6 3 Low Power Mode 7 6 4 Sensitivity adjustment 8 7 APPL...

Page 3: ...nt anti interference performance built in voltage regulator circuit power on reset low voltage reset function and environment adaptive algorithm and other measures Low power standby current Typical va...

Page 4: ...ture Diagram Sensor oscillator circuit Sensor Reference detecting circuit Timing counter function option control circuit System oscillator circuit Regulator circuit Touch detecting circuit Key on Timi...

Page 5: ...output pin 2 GND P Negative power supply ground 3 TK I Touch key sensor input pin 4 AHLB I PL Output QC active high or low selection 0 Default Active high 1 Active low 5 VDD P Positive power supply 6...

Page 6: ...ive power supply ground 3 TK I Touch key sensor input pin 4 AHLB I PL Output QC active high or low selection 0 Default Active high 1 Active low 5 VDD P Positive power supply 6 TOG I PL Output type sel...

Page 7: ...output time of key Objects covering the touchpad or sudden changes in the environment may cause touch detection to remain active The system will return to the initial state of power on and the output...

Page 8: ...conditions are fixed Using a larger touchpad size can increase sensitivity Otherwise it can decrease sensitivity But the touchpad size must use in the effective scope 2 By the panel thickness Under o...

Page 9: ...nclude the metal or the electric element The paints on the surfaces are the same 4 The C1 capacitor 104 or larger must be used between VDD and GND and should be routed with very short tracks to the de...

Page 10: ...TA 25 unless otherwise indicated Parameter Symbol Conditions Min Typ Max Unit Working voltage VDD 2 4 3 5 5 V Internal Regulator Output VREG 2 0 2 2 2 4 V High level input voltage VIH 0 75 1 0 VDD Lo...

Page 11: ...9 1 SOT23 6 Symbol Millimeter Min Nom Max A 1 25 A1 0 04 0 10 A2 1 00 1 10 1 20 A3 0 55 0 65 0 75 b 0 38 0 48 b1 0 37 0 40 0 43 c 0 11 0 21 c1 0 10 0 13 0 16 D 2 72 2 92 3 12 E 2 60 2 80 3 00 E1 1 40...

Page 12: ...12 12 SC7020x www mcu com cn Rev 1 1 10 Version Revision Version number Time Revised content V1 0 May 2020 Original version V1 1 Dec 2021 Delete some chip products...