MAX11800GTC/V+T Maxim Integrated Products, MAX11800GTC/V+T Datasheet - Page 36

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MAX11800GTC/V+T

Manufacturer Part Number
MAX11800GTC/V+T
Description
IC TOUCH SCREEN CTRLR LP 12WQFN
Manufacturer
Maxim Integrated Products
Type
Resistiver
Datasheet

Specifications of MAX11800GTC/V+T

Touch Panel Interface
4-Wire
Number Of Inputs/keys
1 TSC
Resolution (bits)
12 b
Data Interface
Serial, SPI™
Data Rate/sampling Rate (sps, Bps)
105k
Voltage - Supply
1.7 V ~ 3.6 V
Operating Temperature
-40°C ~ 105°C
Mounting Type
Surface Mount
Package / Case
12-WQFN Exposed Pad
Voltage Supply Source
Single Supply
Sampling Rate (per Second)
105k
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Low-Power, Ultra-Small Resistive Touch-Screen
Controllers with I
When the MAX11800/MAX11801 operate in autonomous
conversion mode with low or no aperture ranges, the
FIFO and interrupt activity occur frequently with the AP
servicing the devices frequently to avoid loss of data
due to limited FIFO depth. For this reason, do not per-
form autonomous conversion for applications where a
high resolution in either space or time is required. Use
direct conversion mode when requiring a high resolu-
tion in either space or time.
Figure 16 shows an example of a touch sequence. A
dragged touch sequence is initiated at position 1 and
continues through to position 5. While multiple samples
are taken during this sequence, only those samples
Figure 16. Aperture Usage Example Waveforms—MAX11800/MAX11801
36
______________________________________________________________________________________
Examples of Using Aperture Mode
TIRQ
TIRQ
TIRQ
NOTE: POSITION 5 IS LOGGED EVEN THOUGH POSITION 5 APPEARS IN APER4 BECAUSE POSITION 5 IS A RELEASE DATA POINT.
16
12
IT IS THE SAME FOR POSITION 7. IF THE POSITION 6 TOUCH EVENT INITIATES WITHIN THE FINAL APERTURE FROM THE
PREVIOUS EVENT (APER4), POSITION 6 IS LOGGED AS AN INITIAL TOUCH EVENT.
8
4
0
PANEL TOUCH SPATIAL WAVEFORM
INTERRUPT TIMING WAVEFORM 1 (ASSUMING FREQUENT SERVICING EVENTS WITH APERTURE MODE ENABLED)
INTERRUPT TIMING WAVEFORM 2 (ASSUMING FREQUENT SERVICING EVENTS WITH APERTURE MODE DISABLED)
INTERRUPT TIMING WAVEFORM 3 (ASSUMING INFREQUENT SERVICING EVENTS)
1
1
(1) IRQ ISSUED
2
2
APER1
4
INITIAL
TOUCH
2
1
C/SPI Interface
AND ONE PRESS EVENT (6:7)
8
APER2
ONE DRAG EVENT (1:5)
3
3
DRAG
DRAG
2
4
4
12
APER3
5
5
3
that meet aperture requirements are enumerated and
are shown with the corresponding aperture ranges.
Positions 6 and 7 show a subsequent momentary press
event.
Figure 16 shows the anticipated interrupt waveforms in
several operating modes. The first waveform shows
interrupt operation assuming that aperture mode is
enabled (with ΔX = ΔY = 4 LSBs), assuming that the AP
service interrupts at a frequency faster than the select-
ed TSC sample rate. Each qualifying sample induces a
FIFO event and an interrupt pulse as shown. Timing
between FIFO events can be timed by the AP to deter-
mine duration information. Table 14 shows the read-
back data assuming that the FIFO does not fill up.
(SERVICED) IRQ RELEASED
DRAG
6
6
16
4
APER4
RELEASE
INITIAL
7
7
5
20
DRAG
SECOND
TOUCH
APER6
SECOND
RELEASE
6
7
24

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