Cypress Semiconductor CY8C21x34 Datenblatt

CY8C21x34/B CapSense® Design Guide Doc. No 001-66271 Rev. *B Cypress Semiconductor 198 Champion Court San Jose, CA 95134-1709

10 Document No. 001-66271 Rev. *B CY8C21x34/B CapSense® Design Guide 1.4 Document Conventions Convention Usage Courier New Displays file locat

CY8C21x34/B CapSense® Design Guide Document No. 001-66271 Rev. *B 11 2. CapSense Technology 2.1 CapSense Fundamentals CapSense is a touch-sens

12 Document No. 001-66271 Rev. *B CY8C21x34/B CapSense® Design Guide Figure 2-2. Cross Section of Typical CapSense PCB with the Sensor Being Act

CY8C21x34/B CapSense® Design Guide Document No. 001-66271 Rev. *B 13 2.2 CapSense Methods in CY8C21x34/B CY8C21x34/B devices support several CapS

14 Document No. 001-66271 Rev. *B CY8C21x34/B CapSense® Design Guide Figure 2-4. CSD Raw Counts during a Finger Touch 2.2.2 CSD with ADC Funct

CY8C21x34/B CapSense® Design Guide Document No. 001-66271 Rev. *B 15 SmartSense Auto-tuning makes platform designs possible. Imagine the capacitive

16 Document No. 001-66271 Rev. *B CY8C21x34/B CapSense® Design Guide 3. CapSense Design Tools 3.1 Overview of CapSense Design Tools Cypress

CY8C21x34/B CapSense® Design Guide Document No. 001-66271 Rev. *B 17 7. Generate the application and switch to Application Editor. 8. Adapt sampl

18 Document No. 001-66271 Rev. *B CY8C21x34/B CapSense® Design Guide 3.1.3 Universal CapSense Controller Module Board Cypress’s module boards f

CY8C21x34/B CapSense® Design Guide Document No. 001-66271 Rev. *B 19 Figure 3-4. Raw Count, Baseline, Difference Count, and Sensor State Difference

Copyrights 2 Document No. 001-66271 Rev. *B CY8C21x34/B CapSense® Design Guide Copyrights © Cypress Semiconductor Corporation, 2010–2011. The in

20 Document No. 001-66271 Rev. *B CY8C21x34/B CapSense® Design Guide Sensor states are updated by the user module API UMname_bIsAnySensorActive()

CY8C21x34/B CapSense® Design Guide Document No. 001-66271 Rev. *B 21 3.6 CSD User Module High-Level Parameters 3.6.1 Finger Threshold The Finge

22 Document No. 001-66271 Rev. *B CY8C21x34/B CapSense® Design Guide Figure 3-6. Sensor State Versus Difference Count with Hysteresis Set to Zero

CY8C21x34/B CapSense® Design Guide Document No. 001-66271 Rev. *B 23  Negative Noise Threshold: Set equal to Noise Threshold  Low Baseline Rese

24 Document No. 001-66271 Rev. *B CY8C21x34/B CapSense® Design Guide 3.7.3 Reference A voltage reference to the input of the comparator is requ

CY8C21x34/B CapSense® Design Guide Document No. 001-66271 Rev. *B 25 Because it needs a lower switching frequency, you should use configuration whe

26 Document No. 001-66271 Rev. *B CY8C21x34/B CapSense® Design Guide 3.10.3 Reference A voltage reference to the input of the comparator is req

CY8C21x34/B CapSense® Design Guide Document No. 001-66271 Rev. *B 27 3.11 SmartSense User Module Parameters Figure 3-8. PSoC Designer SmartSense

28 Document No. 001-66271 Rev. *B CY8C21x34/B CapSense® Design Guide 3.12.6 Finger Threshold This parameter is applicable only when threshold s

CY8C21x34/B CapSense® Design Guide Document No. 001-66271 Rev. *B 29 4. CapSense Performance Tuning with User Modules Optimal user module param

CY8C21x34/B CapSense® Design Guide Document No. 001-66271 Rev. *B 3 Contents 1. Introduction ...

30 Document No. 001-66271 Rev. *B CY8C21x34/B CapSense® Design Guide 4.1.1.2 CapSense Noise CapSense noise is the peak-to-peak variation in senso

CY8C21x34/B CapSense® Design Guide Document No. 001-66271 Rev. *B 31 Figure 4-3. Charge/Discharge Waveforms VsVxVddVrefVddVrefttRxCxVsVx5*Rx*Cx5*Rx

32 Document No. 001-66271 Rev. *B CY8C21x34/B CapSense® Design Guide 4.2 Tuning the CSD and CSDADC User Modules Figure 4-4. Tuning CSD and CSDA

CY8C21x34/B CapSense® Design Guide Document No. 001-66271 Rev. *B 33 4.2.1 Set Up Hardware and Software for Tuning Before starting the tuning pro

34 Document No. 001-66271 Rev. *B CY8C21x34/B CapSense® Design Guide raw count value in a no touch condition. Increasing Rb also decreases the ma

CY8C21x34/B CapSense® Design Guide Document No. 001-66271 Rev. *B 35  Under Global Settings in the CapSense wizard, assign one sensor under the c

36 Document No. 001-66271 Rev. *B CY8C21x34/B CapSense® Design Guide Figure 4-7. Monitoring the Sensor Signal baSnsSignal Now open the CapSense

CY8C21x34/B CapSense® Design Guide Document No. 001-66271 Rev. *B 37 5. Design Considerations When designing capacitive touch sense technology i

38 Document No. 001-66271 Rev. *B CY8C21x34/B CapSense® Design Guide 5.2 ESD Protection Robust ESD tolerance is a natural byproduct of careful

CY8C21x34/B CapSense® Design Guide Document No. 001-66271 Rev. *B 39  The recommended series resistance for communication lines, such as I2C, and

4 Document No. 001-66271 Rev. *B CY8C21x34/B CapSense® Design Guide 3.6.6 Debounce ...

40 Document No. 001-66271 Rev. *B CY8C21x34/B CapSense® Design Guide Table 5-4 shows the RAM and flash requirements for different software filter

CY8C21x34/B CapSense® Design Guide Document No. 001-66271 Rev. *B 41 The average power consumed by the device can be calculated as follows:

42 Document No. 001-66271 Rev. *B CY8C21x34/B CapSense® Design Guide 5.6 Pin Assignments An effective method to reduce interaction between CapS

CY8C21x34/B CapSense® Design Guide Document No. 001-66271 Rev. *B 43 6. Water Tolerance Some CapSense capacitive touch-sensing applications requ

44 Document No. 001-66271 Rev. *B CY8C21x34/B CapSense® Design Guide Figure 6-2. Capacitance Measurement with Water Drop  CWD – Capacitance be

CY8C21x34/B CapSense® Design Guide Document No. 001-66271 Rev. *B 45 Figure 6-3. Schematic View of Digital Interconnect 5. Select Row_0_Output_2_

46 Document No. 001-66271 Rev. *B CY8C21x34/B CapSense® Design Guide 6.1.2 Guard Sensor Figure 6-5. PCB with Shield and Guard Sensor PCB

CY8C21x34/B CapSense® Design Guide Document No. 001-66271 Rev. *B 47 A guard sensor is a copper trace, as shown in Figure 6-5, that surrounds all t

48 Document No. 001-66271 Rev. *B CY8C21x34/B CapSense® Design Guide Figure 6-7. Flow Chart to Implement the Guard Sensor Start of main functionE

CY8C21x34/B CapSense® Design Guide Document No. 001-66271 Rev. *B 49 7. Proximity Sensing Proximity sensors detect the presence of a hand or oth

CY8C21x34/B CapSense® Design Guide Document No. 001-66271 Rev. *B 5 5.1 Overlay Selection ...

50 Document No. 001-66271 Rev. *B CY8C21x34/B CapSense® Design Guide 7.2 Design Recommendations Using a shield electrode effectively extends th

CY8C21x34/B CapSense® Design Guide Document No. 001-66271 Rev. *B 51 8. Low Power Design Considerations Power consumption is an important aspec

52 Document No. 001-66271 Rev. *B CY8C21x34/B CapSense® Design Guide 8.1.2 Putting it All Together The following code is a sample of a typical

CY8C21x34/B CapSense® Design Guide Document No. 001-66271 Rev. *B 53 8.2 Post Wakeup Execution Sequence If the CapSense controller is awakened th

54 Document No. 001-66271 Rev. *B CY8C21x34/B CapSense® Design Guide Figure 8-1. Sleep Timer User Module Block Diagram

CY8C21x34/B CapSense® Design Guide Document No. 001-66271 Rev. *B 55 9. Resources 9.1 Website The Cypress CapSense Controllers website gives

56 Document No. 001-66271 Rev. *B CY8C21x34/B CapSense® Design Guide 9.4.2.3 Linear Slider Module Board The CY3280-SLM Linear Slider Module consi

CY8C21x34/B CapSense® Design Guide Document No. 001-66271 Rev. *B 57  CMPPRG User Module Example  Receive String using CYRF6936 and CY8C27643 

6 Document No. 001-66271 Rev. *B CY8C21x34/B CapSense® Design Guide 9.1 Website ...

CY8C21x34/B CapSense® Design Guide Document No. 001-66271 Rev. *B 7 1. Introduction 1.1 Abstract This document gives design guidance for usin

8 Document No. 001-66271 Rev. *B CY8C21x34/B CapSense® Design Guide Figure 1-1. Typical CapSense Product Design Flow 2. CapSense device selection

CY8C21x34/B CapSense® Design Guide Document No. 001-66271 Rev. *B 9 1.3 CY8C21x34/B CapSense Plus Family Features Cypress’s CY8C21x34/B is a low