MCIMX25 Motorola Semiconductor Products, MCIMX25 Datasheet - Page 109

• Manufacturer Part Number: MCIMX25
• Manufacturer: Motorola Semiconductor Products

1
2
3
4
3.6.18.2
Figure 82
of the internal ADC. After a conversion cycle eoc is asserted, a new conversion begins only when the
assertion of soc is detected. Thus, if the soc signal is continuously asserted, the ADC undergoes successive
conversion cycles and achieves the maximum sampling rate. If soc is negated, no conversion is initiated.
Freescale Semiconductor
Current consumption
NVCC_ADC
QV
Power-down current
NVCC_ADC
QV
Expected plate resistance
Switch drivers on
resistance
DNL
INL
Gain + Offset Error
This comprises only the required initial dummy conversion cycle. Additional power-up time depends on the enadc , reset and
soc signals applied to the touchscreen controller.
This value only includes the ADC and the driver switches, but it does not take into account the current consumption in the
touchscreen plate. For example, if the plate resistance is 100 W, the total current consumption is about 33 mA.
At avdd = 3.3 V, dvdd = 1.2 V, Tjunction = 50 °C, fclk = 1.75 MHz, any process corner, unless otherwise noted.
Value measured with a –0.5 dBFS sinusoidal input signal and computed with the code density test.
DD
DD
4
4
Parameter
represents the synchronization between the signals clk, soc, eoc, and the output bits in the usage
ADC Timing Diagrams
2
i.MX25 Applications Processor for Consumer and Industrial Products, Rev. 2
Table 81. Touchscreen ADC Electrical Specifications (continued)
GND and VDD switches
fin = 1 kHz
fin = 1 kHz
Power Supply Requirements
Conversion Characteristics
Conditions
Touchscreen Interface
—
—
—
—
3
Min.
100
—
—
—
—
—
—
+/–0.75
+/–2.0
Typ.
—
—
—
—
—
Max.
1500
+/–2
2.1
0.5
10
10
—
—
1
%FS
Unit
LSB
LSB
mA
mA
uA
uA
109