ZHCSDC3E June 2014 – January 2019 AM4372 , AM4376 , AM4377 , AM4378 , AM4379
PRODUCTION DATA.
The touch screen controller (TSC) and analog-to-digital converter (ADC) subsystem (ADC0) contains a single-channel ADC connected to an 8:1 analog multiplexer which operates as a general-purpose ADC with optional support for interleaving TSC conversions for 4-wire, 5-wire, or 8-wire resistive panels. The ADC0 subsystem can be configured for use in one of the following applications:
Table 5-5 summarizes the ADC0 subsystem electrical parameters.
| PARAMETER | TEST CONDITIONS | MIN | NOM | MAX | UNIT |
|---|---|---|---|---|---|
| ANALOG INPUT | |||||
| ADC0_VREFP(1) | (0.5 × VDDA_ADC0) + 0.25 | VDDA_ADC0 | V | ||
| ADC0_VREFN(1) | 0 | (0.5 × VDDA_ADC0) – 0.25 | V | ||
| ADC0_VREFP + ADC0_VREFN | VDDA_ADC0 | V | |||
| Full-scale Input Range | Internal Voltage Reference | 0 | VDDA_ADC0 | V | |
| External Voltage Reference | ADC0_VREFN | ADC0_VREFP | |||
| Differential Nonlinearity (DNL) | Internal Voltage Reference:
VDDA_ADC0 = 1.8 V External Voltage Reference: VREFP – VREFN = 1.8 V |
–1 | 0.5 | 1 | LSB |
| Integral Nonlinearity (INL) | Source impedance = 50 Ω
Internal Voltage Reference: VDDA_ADC0 = 1.8 V External Voltage Reference: VREFP – VREFN = 1.8 V |
–2 | ±1 | 2 | LSB |
| Source Impedance = 1 kΩ
Internal Voltage Reference: VDDA_ADC0 = 1.8 V External Voltage Reference: VREFP – VREFN = 1.8 V |
±1 | ||||
| Gain Error | Internal Voltage Reference:
VDDA_ADC0 = 1.8 V External Voltage Reference: VREFP – VREFN = 1.8 V |
±2 | LSB | ||
| Offset Error | Internal Voltage Reference:
VDDA_ADC0 = 1.8 V External Voltage Reference: VREFP – VREFN = 1.8 V |
±2 | LSB | ||
| Input Sampling Capacitance | 5.5 | pF | |||
| Signal-to-Noise Ratio (SNR) | Internal Voltage Reference:
VDDA_ADC0 = 1.8 V External Voltage Reference: VREFP – VREFN = 1.8 V Input Signal: 30 kHz sine wave at –0.5 dB Full Scale |
70 | dB | ||
| Total Harmonic Distortion (THD) | Internal Voltage Reference:
VDDA_ADC0 = 1.8 V External Voltage Reference: VREFP – VREFN = 1.8 V Input Signal: 30 kHz sine wave at –0.5 dB Full Scale |
75 | dB | ||
| Spurious Free Dynamic Range | Internal Voltage Reference:
VDDA_ADC0 = 1.8 V External Voltage Reference: VREFP – VREFN = 1.8 V Input Signal: 30 kHz sine wave at –0.5 dB Full Scale |
80 | dB | ||
| Signal-to-Noise Plus Distortion | Internal Voltage Reference:
VDDA_ADC0 = 1.8 V External Voltage Reference: VREFP – VREFN = 1.8 V Input Signal: 30 kHz sine wave at –0.5 dB Full Scale |
69 | dB | ||
| VREFP and VREFN Input Impedance | 20 | kΩ | |||
| Input Impedance of AIN[7:0](2) | f = input frequency | [1/((65.97 × 10–12) × f)] | Ω | ||
| SAMPLING DYNAMICS | |||||
| ADC Clock Frequency | 13 | MHz | |||
| Conversion Time | 13 | ADC0 clock cycles | |||
| Acquisition Time | 2 | 257 | ADC0 clock cycles | ||
| Sampling Rate(3) | ADC0 Clock = 13 MHz | 867 | kSPS | ||
| Channel-to-Channel Isolation | 100 | dB | |||
| TOUCH SCREEN SWITCH DRIVERS | |||||
| Pullup and Pulldown Switch ON-Resistance (Ron) | 2 | Ω | |||
| Pullup and Pulldown Switch Current Leakage Ileak | Source impedance = 500 Ω | 0.5 | uA | ||
| Drive Current | 25 | mA | |||
| Touch Screen Resistance | 6 | kΩ | |||
| Pen Touch Detect | 2 | kΩ | |||