UM10208_2
© NXP B.V. 2007. All rights reserved.
User manual
Rev. 02 — 1 June 2007
246 of 362
1.
Features
•
10 bit successive approximation analog to digital converter.
•
Input multiplexing among 5 dedicated pins.
•
Power down mode.
•
Measurement range 0 to 3 V.
•
10 bit conversion time
≥
2.44
μ
s.
•
Single or continuous conversion mode.
•
Separate 10-bit result register for each input channel.
2.
Description
Basic clocking for the A/D converter is provided by the Clock Generation Unit (CGU),
which can be programmed to provide a clock between 31.25 kHz and the maximum rate
of 4.5 MHz. A fully accurate conversion requires 11 of these clocks.
3.
Pin description
gives a brief summary of the pads related to the ADC.
UM10208
Chapter 18: Analog-to-Digital Converter (ADC)
Rev. 02 — 1 June 2007
User manual
Table 275. A/D pin description
Pin
Type
Description
AIN4:0
Input
Analog Inputs.
These are dedicated pads, with no digital I/O capability.
Unused pins can be left unconnected.
DCDC_Vbat
Input
This pad is internally connected to the sixth analog input of the ADC.
V
DD(ADC3V3)
Power
Analog Power and Voltage Reference.
This pin provides both power and
the upper reference voltage for the A/D converter. If the A/D converter is
never used, this pin and ADC_VSS should be grounded.
V
SS(ADC)
Power
Analog Ground.
This pin provides both power return and the lower
reference voltage for the A/D converter.