MAX11800_10 Datasheet, PDF (49/57 Pages) Maxim Integrated Products – Low-Power, Ultra-Small Resistive Touch-Screen Controllers with I2C/SPI Interface

Low-Power, Ultra-Small Resistive Touch-Screen
Controllers with I²C/SPI Interface
Measurement Averaging Configuration Register (0x03)*
NAME
DEFAULT
BIT 7
BIT 6
AVG_X[1:0]
0
0
BIT 5
BIT 4
AVG_Y[1:0]
0
0
BIT 3
BIT 2
AVG_Z1[1:0]
0
0
BIT 1
BIT 0
AVG_Z2[1:0]
0
0
BIT
NAME
DESCRIPTION
7:6
AVG_X[1:0]
5:4
AVG_Y[1:0]
3:2
AVG_Z1[1:0]
1:0
AVG_Z2[1:0]
Averaging sample depth for X, Y, Z1, or Z2 measurements
If AVG_FLT = 0 (see the Operating Mode Configuration Register (0x0B) section)
00: Single sample, no averaging
01: Take four samples, average two median samples
10: Take eight samples, average four median samples
11: Take 16 samples, average eight median samples
If AVG_FLT = 1 (see the Operating Mode Configuration Register (0x0B) section)
00: Single sample, no averaging
01: Take four samples, average all samples
10: Take eight samples, average all samples
11: Take 16 samples, average all samples
*The settings can be enabled and disabled through settings in the operating mode configuration register (0x0B), allowing for dynamic
configuration of averaging modes depending on operating mode.
ADC Sampling Time Configuration Register (0x04)*
NAME
DEFAULT
BIT 7
BIT 6
T_SAMPLE_X[1:0]
0
0
BIT 5
BIT 4
T_SAMPLE_Y[1:0]
0
0
BIT 3
BIT 2
T_SAMPLE_Z1[1:0]
0
0
BIT 1
BIT 0
T_SAMPLE_Z2[1:0]
0
0
BIT
NAME
DESCRIPTION
7:6
T_SAMPLE_X[1:0]
5:4
T_SAMPLE_Y[1:0]
3:2
T_SAMPLE_Z1[1:0]
1:0
T_SAMPLE_Z2[1:0]
Sampling time for X, Y, Z1 or Z2 measurements
00: 4 x (2MHz oscillator clock period) = 2μs
01: 16 x (2MHz oscillator clock period) = 8μs
10: 64 x (2MHz oscillator clock period) = 32μs
11: 256 x (2MHz oscillator clock period) = 128μs
*Time ADC spends sampling panel before starting conversion process. This time plus the ADC conversion time determines the sam-
pling rate within averaging operations. Be sure to allow adequate time to settle the ADC capacitors given the panel effective source
resistance.
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