
Analog Integrated Circuit Device Data
Freescale Semiconductor
91
PC34708
Functional Block Requirements and Behaviors
10 Bit ADC Core Block Description and Application Information
7.6
10 Bit ADC Core Block Description and Application Information
7.6.1
Introduction
The ADC core is a 10 bit converter. The ADC core and logic run at an internally generated frequency of approximately 1.33 MHz.
The ADC is supplied from VCORE. The ADC core has an integrated auto calibration circuit which reduces the offset and gain
errors.
7.6.2
Functional Description
7.6.2.1
Input Selector
The ADC has 16 input channels.
Table 89 gives an overview of the characteristics of each of these channels.
Some of the internal signals are first scaled to adapt the signal range to the input range of the ADC. The battery current is
indirectly read out by the voltage drop over the resistor in the charge path and battery path respectively. For details on scaling,
When considerately exceeding the maximum input of the ADC at the scaled or unscaled inputs, the reading result will return a
full scale. It has to be noted however, that this full scale does not necessarily yield a 1022 DEC reading due to the offsets and
Table 89. ADC Inputs
Channel
Signal read
Input Level
Scaling
Scaled Version
0
Battery Voltage (BATTISNSN)
0 – 4.8 V
/2
0 – 2.4 V
1
Battery Current (BATTISNSN-BATTISNSP)
x15
-1.2 – +1.2 V
2
Application Supply (BPSNS)
0 – 4.8 V
/2
0 – 2.4 V
3
Die temperature
-40 – 150 °C
1.2 – 2.4 V
4
Aux Charger Voltage (VAUX)
0 – 10 V
x0.24
0 – 2.4 V
5
USB Voltage (VBUS)
0 – 6.0 V
x0.4
0 – 2.4 V
6
Reserved
7
Battery Thermistor (BPTHERM)
0 – 2.4 V
x1
0 – 2.4 V
8
Coincell Voltage
0 – 3.6 V
X2/3
0 – 2.4 V
9
ADIN9
0 – 2.4 V
x1
0 – 2.4 V
10
ADIN10
0 – 2.4 V
x1
0 – 2.4 V
11
ADIN11
0 – 2.4 V
x1
0 – 2.4 V
12
ADIN12/TSX1
0 – 2.4 V
x1/x2
0 – 2.4 V
13
ADIN13/TSX2
0 – 2.4 V
x1/x2
0 – 2.4 V
14
ADIN14/TSY1
0 – 2.4 V
x1/x2
0 – 2.4 V
15
ADIN15/TSY2
0 – 2.4 V
x1/x2
0 – 2.4 V
Notes
62.
Equivalent to -4.0 A to +4.0 A of current with a 20 mOhm sense resistor
Table 90. ADC Input Specification
Parameter
Condition
Min Typ Max
Units
Source Impedance
No bypass capacitor at input
5.0
kOhm
Bypass capacitor at input 10 nF
30
kOhm