AM3359, AM3358, AM3357, AM3356, AM3354, AM3352
SPRS717H – OCTOBER 2011 – REVISED MAY 2015
5.10 Touch Screen Controller and Analog-to-Digital Subsystem Electrical Parameters
The touch screen controller (TSC) and analog-to-digital converter (ADC) subsystem (TSC_ADC) is an 8-channel
general-purpose ADC with optional support for interleaving TSC conversions for 4-wire, 5-wire, or 8-wire resistive
panels. The TSC_ADC subsystem can be configured for use in one of the following applications:
•
8 general-purpose ADC channels
•
4-wire TSC with 4 general-purpose ADC channels
•
5-wire TSC with 3 general-purpose ADC channels
•
8-wire TSC.
summarizes the TSC_ADC subsystem electrical parameters.
Table 5-16. TSC_ADC Electrical Parameters
PARAMETER
TEST CONDITIONS
MIN
NOM
MAX
UNIT
Analog Input
(0.5 × VDDA_ADC) +
VDDA_ADC
V
0.25
(0.5 × VDDA_ADC) –
0
V
0.25
VREFP + VREFN
VDDA_ADC
V
Internal voltage reference
0
VDDA_ADC
Full-scale input range
V
External voltage reference
VREFN
VREFP
Internal voltage reference:
Differential non-linearity
VDDA_ADC = 1.8 V
–1
0.5
1
LSB
(DNL)
External voltage reference:
VREFP – VREFN = 1.8 V
Source impedance = 50
Ω
Internal voltage reference:
VDDA_ADC = 1.8 V
–2
±1
2
LSB
External voltage reference:
VREFP – VREFN = 1.8 V
Integral non-linearity (INL)
Source impedance = 1 k
Ω
Internal voltage reference:
VDDA_ADC = 1.8 V
±1
LSB
External voltage reference:
VREFP – VREFN = 1.8 V
Internal voltage reference:
VDDA_ADC = 1.8 V
Gain error
±2
LSB
External voltage reference:
VREFP – VREFN = 1.8 V
Internal voltage reference:
VDDA_ADC = 1.8 V
Offset error
±2
LSB
External voltage reference:
VREFP – VREFN = 1.8 V
Input sampling capacitance
5.5
pF
Internal voltage reference:
VDDA_ADC = 1.8 V
External voltage reference:
Signal-to-noise ratio (SNR)
70
dB
VREFP – VREFN = 1.8 V
Input signal: 30-kHz sine wave at
–0.5-dB full scale
Internal voltage reference:
VDDA_ADC = 1.8 V
Total harmonic distortion
External voltage reference:
75
dB
(THD)
VREFP – VREFN = 1.8 V
Input signal: 30-kHz sine wave at
–0.5-dB full scale
Copyright © 2011–2015, Texas Instruments Incorporated
Specifications
97
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