MC68HC705JP7 Datasheet, PDF (126/242 Pages) Motorola, Inc – HCMOS Microcontroller Unit

Freescale Semiconductor, Inc.
Analog Subsystem
Table 8-4. A/D Conversion Parameters
Name
Function
V_X Unknown voltage on channel selection bus
V_MAX Maximum charging voltage on external capacitor
I_CHG
Charging current on external ramping capacitor
V_DD = 3 Vdc
V_DD = 5 Vdc
I_DIS Discharge current on external ramping capacitor
Min
Typ
Max
Units
V_SS
—
V_DD –1.5
V
—
—
V_DD –1.5
V
Refer to 15.10 Analog Subsystem
Characteristics (5.0 Vdc) and 15.11 Analog
Subsystem Characteristics (3.0 Vdc)
Refer to 15.10 Analog Subsystem
Characteristics (5.0 Vdc) and 15.11 Analog
Subsystem Characteristics (3.0 Vdc)
t_CHG
Time to charge external capacitor
(100 kHz < f_OSC < 4.0 MHz)
4-bit result
6-bit result
8-bit result
10-bit result
12-bit result
t_DIS Time to discharge external capacitor, C_EXT
C_EXT Capacitance of external ramping capacitor
N Number of counts for I_CHG to charge C_EXT to V_X
Prescaler into timing function (÷ P)
P
Using core timer
Using 16-bit programmable timer
Using software loops
f_OSC Clock source frequency (excluding any prescaling)
1. Limited by requirement for C_EXT to be less than 2.0 µF
0.032
0.128
0.512
2.048
8.192
—
0.0001
1
0.128
0.512
2.048
8.196
32.768
5
0.1
1024
2.56
10.24
40.96
120⁽¹⁾
120⁽¹⁾
10
2.0
65536
ms
ms/ µF
µF
Counts
8
8
8
8
8
8
÷P
24
User defined User defined
Refer to 15.12 Control Timing (5.0 Vdc)
and 15.13 Control Timing (3.0 Vdc)
Advance Information
126
MC68HC705JJ7 • MC68HC705JP7 — REV 4
Analog Subsystem
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