 |
Zakładka z wyszukiwarką danych komponentów |
|
|
Zakładka z wyszukiwarką danych komponentów |
|
TSC2200IPWR Arkusz danych(PDF) 9 Page - Texas Instruments |
|
|
||||||||||||||||||||||||||||||
TSC2200IPWR Arkusz danych(HTML) 9 Page - Texas Instruments |
|
|
9 / 45 page  9 www.ti.com TSC2200 SBAS191F FIGURE 2. 4-Wire Touch Screen Construction. FIGURE 3. Pressure Measurement. OPERATION—TOUCH SCREEN A resistive touch screen works by applying a voltage across a resistor network and measuring the change in resistance at a given point on the matrix where a screen is touched by an input stylus, pen, or finger. The change in the resistance ratio marks the location on the touch screen. The TSC2200 supports the resistive 4-wire configurations (see Figure 1). The circuit determines location in two coordi- nate pair dimensions, although a third dimension can be added for measuring pressure. THE 4-WIRE TOUCH SCREEN COORDINATE PAIR MEASUREMENT A 4-wire touch screen is constructed as shown in Figure 2. It consists of two transparent resistive layers separated by insulating spacers. The 4-wire touch screen panel works by applying a voltage across the vertical or horizontal resistive network. The A/D converter converts the voltage measured at the point the panel is touched. A measurement of the Y-position of the pointing device is made by connecting the X+ input to a data converter chip, turning on the Y+ and Y– drivers, and digitizing the voltage seen at the X+ input. The voltage measured is determined by the voltage divider developed at the point of touch. For this measurement, the horizontal panel resistance in the X+ lead does not affect the conver- sion due to the high input impedance of the A/D converter. Voltage is then applied to the other axis, and the A/D converter converts the voltage representing the X-position on the screen. This provides the X- and Y-coordinates to the associated processor. Measuring touch pressure (Z) can also be done with the TSC2200. To determine pen or finger touch, the pressure of the “touch” needs to be determined. Generally, it is not necessary to have very high performance for this test, there- fore, the 8-bit resolution mode is recommended (however, calculations will be shown with the 12-bit resolution mode). There are several different ways of performing this measure- ment. The TSC2200 supports two methods. The first method requires knowing the X-plate resistance, measurement of the X-position, and two additional cross panel measurements (Z2 and Z1) of the touch screen, as seen in Figure 3. Using Equation 1 will calculate the touch resistance: RR X-Position 4096 Z Z –1 TOUCH X-Plate 2 1 = • (1) The second method requires knowing both the X-plate and Y-plate resistance, measurement of X-position and Y-posi- tion, and Z1. Using Equation 2 will also calculate the touch resistance: (2) RR X Position Z R Y Position TOUCH X Plate Y Plate =• − −• − -- -- 4096 4096 11 4096 1 When the touch panel is pressed or touched, and the drivers to the panel are turned on, the voltage across the touch panel will often overshoot and then slowly settle (decay) down to a stable DC value. This is due to mechanical bouncing which is caused by vibration of the top layer sheet of the touch panel when the panel is pressed. This settling time must be accounted for, or else the converted value will be in error. Therefore, a delay must be introduced between the time the driver for a particular measurement is turned on, and the time measurement is made. Conductive Bar Insulating Material (Glass) Silver Ink Transparent Conductor (ITO) Bottom Side Transparent Conductor (ITO) Top Side X+ X– Y+ Y– ITO = Indium Tin Oxide X-Position Measure X-Position Measure Z 1-Position Touch X+ Y+ X– Y– Z 1-Position Touch X+ Y+ Y– X– Measure Z 2-Position Z 2-Position Touch X+ Y+ Y– X– |
Podobny numer części - TSC2200IPWR |
|
Podobny opis - TSC2200IPWR |
|
|
Link URL |
| Polityka prywatności |
| ALLDATASHEET.PL |
| Czy Alldatasheet okazała się pomocna? [ DONATE ] |
O Alldatasheet | Reklama | Kontakt | Polityka prywatności | Linki | Lista producentów All Rights Reserved©Alldatasheet.com |
| Russian : Alldatasheetru.com | Korean : Alldatasheet.co.kr | Spanish : Alldatasheet.es | French : Alldatasheet.fr | Italian : Alldatasheetit.com Portuguese : Alldatasheetpt.com | Polish : Alldatasheet.pl | Vietnamese : Alldatasheet.vn Indian : Alldatasheet.in | Mexican : Alldatasheet.com.mx | British : Alldatasheet.co.uk | New Zealand : Alldatasheet.co.nz |
|
Family Site : ic2ic.com |
icmetro.com |
Polish ▼
English
Chinese
German
Japanese
Russian
Korean
Spanish
French
Italian
Portuguese
Polish
Vietnamese
Indian
Mexican
British
New Zealand
