MC68HC705JP7CDW Freescale Semiconductor, MC68HC705JP7CDW Datasheet - Page 83

• Manufacturer Part Number: MC68HC705JP7CDW
• Description: IC MCU 8BIT 28-SOIC
• Manufacturer: Freescale Semiconductor
• Series: HC05r

Specifications of MC68HC705JP7CDW

• Core Processor: HC05
• Core Size: 8-Bit
• Speed: 2.1MHz
• Connectivity: SIO
• Peripherals: POR, Temp Sensor, WDT
• Number Of I /o: 22
• Program Memory Size: 6KB (6K x 8)
• Program Memory Type: OTP
• Ram Size: 224 x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Data Converters: A/D 4x12b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 28-SOIC (7.5mm Width)
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Eeprom Size: -

The full scale voltage range for a given capacitance, f
as:
Once charged to a given voltage, a finite amount of time will be required to discharge the capacitor back
to its start voltage at V
the sinking current of the internal discharge device. To allow a reasonable time for the capacitor to return
to V
attached to the PB0 pin. If the total charge/discharge cycle time is critical, then the discharge time should
be at least 1/10 of the most recent charge time. Shorter discharge times may be used if lesser accuracy
in the voltage measurement is acceptable.
Table 8-4
some A/D conversion examples for several bit resolutions.
The mode selection bits in the ACR allow four methods of single-slope A/D conversion. Each of these
methods is shown in
Table
Freescale Semiconductor
Name
V
C
I
t
I
t
CHG
CHG
V
MAX
•
•
•
•
DIS
DIS
EXT
N
SS
X
8-4.
Manual start and stop (mode 0)
Manual start and automatic discharge (mode 1)
Automatic start and stop from TOF to ICF (mode 2)
Automatic start and stop from OCF to ICF (mode 3)
levels, the discharge time should last about 10 milliseconds per microfarad of capacitance
Unknown voltage on channel selection bus
Maximum charging voltage on external capacitor
Charging current on external ramping capacitor
Discharge current on external ramping capacitor
Time to charge external capacitor
(100 kHz < f
Time to discharge external capacitor, C
Capacitance of external ramping capacitor
Number of counts for I
gives the range of values of each parameter in the A/D timing conversion and
V
V
4-bit result
6-bit result
8-bit result
10-bit result
12-bit result
DD
DD
Sufficient time should be allowed to discharge the external capacitor or
subsequent charge times will be shortened with resultant errors in timing
conversion.
= 3 Vdc
= 5 Vdc
OSC
MC68HC705JJ7 • MC68HC705JP7 Advance Information Data Sheet, Rev. 4.1
Figure 8-8
SS
< 4.0 MHz)
. This discharge time will be solely based on the value of capacitance used and
Function
CHG
to charge C
Table 8-4. A/D Conversion Parameters
V
through
FS
= N
Figure 8-8
EXT
Figure 8-11
FS
EXT
to V
x P x I
X
NOTE
CHG
Refer to
Refer to
using the signal names and parameters given in
OSC
Figure 8-9
0.0001
0.032
0.128
0.512
2.048
8.192
/ (C
Min
V
15.10 Analog Subsystem Characteristics (3.0 Vdc)
15.10 Analog Subsystem Characteristics (3.0 Vdc)
—
—
, conversion method, and resolution is defined
1
SS
Figure 8-10
15.9 Analog Subsystem Characteristics (5.0 Vdc)
15.9 Analog Subsystem Characteristics (5.0 Vdc)
Figure 8-11
EXT
x f
OSC
32.768
0.128
0.512
2.048
8.196
1024
Typ
)
0.1
—
—
5
A/D Conversion Methods
Continued on next page
V
V
65536
DD
DD
120
120
10.24
40.96
Max
2.56
2.0
10
–1.5
–1.5
Table 8-5
(1)
(1)
Counts
ms/µF
Units
gives
ms
µF
V
V
and
and
83