TSC2102

SLAS379A− APRIL 2003 − REVISED JUNE 2004

www.ti.com

44

The time for a complete X/Y/Z1/Z2 coordinate conversion is given by(not including the time needed to send the command

over the SPI bus):

t

coordinate +

3

t

PRE )

t

SNS )

t

PVS

125 ns

t

OSC )

4

N

AVG

N

BITS )

1

8MHz

ƒconv

) n

1 )

12

) 1

t

OSC )

33

t

OSC )

n

2

t

OSC )

n

3

t

OSC

7 ; if

NOTE: The above formula is exactly valid only when the audio DAC is powered down. Also after touch detect the formula holds true from second

conversion onwards. For continuous touch and D15−D14 = 00/10/11, the high duration of the PINTDAV signal is given by tPRE + tSNS with

an oscillator clock of 8 MHz.

Programmed

for Self

Controlled

X−Y−Z1−Z2

Scan

Mode

Detecting Touch

Sample,Conversion &

Averaging for

Y−Coordinate

Reading

X−Data

Register

Reading

Y−Data

Register

Detecting

Touch

Sample,Conversion &

Averaging for

X−Coordinate

Detecting

Touch

Sample,Conversion &

Averaging for

Z1−Coordinate & Z2−Coordinate

Reading

Z1−Data

Register

Reading

Z2−Data

Register

Detecting

Touch

Sample,Conversion &

Averaging for

Y−Coordinate

Detecting

Touch

SS DEACTIVATED

(As PENIRQ

[D15−D14 = 00])

PINTDAV

(As PENIRQ & DATA_AVA

[D15−D14 = 10/11])

PINTDAV

Touch Is Detected

Touch Is Detected

Touch Is Detected

Touch Is Detected

(As DATA_AVA

[D15−D14 = 01])

PINTDAV

Touch Screen Conversion Initiated by the Host

The time needed to convert any single coordinate either X or Y under host control (not including the time needed to send

the command over the SPI bus) is given by:

t

coordinate +

t

PVS

125 ns

t

OSC )

N

AVG

N

BITS )

1

8MHz

ƒconv

) n

1 )

12

) 1

t

OSC )

14

t

OSC )

n

2

t

OSC

7 ; if

NOTE: For continuous touch and D15−D14 = 00/10/11, the high duration of the PINTDAV signal is given by tPRE + tSNS with an oscillator clock of

8 MHz.