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20. 10-bit AD Converter (ADC)
20.7 Precautions about the AD Converter
TMP89FM42
RA001
20.7 Precautions about the AD Converter
20.7.1 Analog input pin voltage range
Analog input pins (AIN0 through AIN7) should be used at voltages from VAREF to VSS. If any voltage out-
side this range is applied to one of the analog input pins, the converted value on that pin becomes uncertain,
and converted values on other pins will also be affected.
20.7.2 Analog input pins used as input/output ports
Analog input pins (AIN0 to AIN7) are also used as input/output ports. In using one of analog input pins
(ports) to execute AD conversion, input/output instructions at all other pins (ports) must not be executed. If
they are executed, there is the possibility that the accuracy of AD conversion may deteriorate. This also applies
to pins other than analog input pins; if one pin receives inputs or generates outputs, noise may occur and its
adjacent pins may be affected by that noise.
20.7.3 Noise countermeasure
The internal equivalent circuit of the analog input pins is shown in Figure 20-5. The higher the output imped-
ance of the analog input source, the more susceptible it becomes to noise. Therefore, make sure the output
impedance of the signal source in your design is 5 k
Ω
or less. It is recommended that a capacitor be attached
externally.
Figure 20-5 Analog Input Equivalent Circuit and Example of Input Pin Processing
DA converter
Analog comparator
rnal resistance:
rnal capacitance:
#!Undefined!# k
Ω
(typ)
DA converter
AINi
Analog comparator
Internal resistance:
Permissible signal
source impedance:
Internal capacitance:
5 k
Ω
(typ)
5 k
Ω
(max)
Note) i = 7 to 0
C = 22 pF (typ.)
Содержание TLCS-870/C1 Series
Страница 1: ...8 Bit Microcontroller TLCS 870 C1 Series TMP89FM42 查询TMP89FM42供应商 捷多邦 专业PCB打样工厂 24小时加急出货 ...
Страница 3: ...Revision History Date Revision 2007 10 25 1 First Release 2007 11 3 2 Contents Revised ...
Страница 4: ......
Страница 14: ......
Страница 18: ...1 3 Block Diagram TMP89FM42 1 3 Block Diagram Figure 1 2 Block Diagram ...
Страница 22: ...1 4 Pin Names and Functions TMP89FM42 ...
Страница 60: ...2 CPU Core 2 5 Revision History TMP89FM42 ...
Страница 76: ...3 Interrupt Control Circuit 3 8 Revision History TMP89FM42 ...
Страница 86: ...4 External Interrupt control circuit 4 3 Function TMP89FM42 ...
Страница 102: ...7 Voltage Detection Circuit 7 5 Revision History TMP89FM42 ...
Страница 126: ...8 I O Ports 8 3 I O Port Registers TMP89FM42 Note 2 i 0 to 1 ...
Страница 136: ...8 I O Ports 8 5 Revision History TMP89FM42 ...
Страница 142: ...9 Special Function Registers 9 3 SFR3 0x0E40 to 0x0EFF TMP89FM42 ...
Страница 146: ...10 Low Power Consumption Function for Peripherals TMP89FM42 ...
Страница 149: ...TMP89FM42 11 3 Revision History Rev Description RA001 Deleted SLEEP2 description ...
Страница 150: ...11 Divider Output DVO 11 3 Revision History TMP89FM42 ...
Страница 220: ...15 Real Time Clock RTC 15 4 Real Time Clock Operation TMP89FM42 ...
Страница 250: ...16 Asynchronous Serial Interface UART 16 15 Revision History TMP89FM42 ...
Страница 302: ...18 Serial Bus Interface SBI 18 7 Revision History TMP89FM42 ...
Страница 336: ...21 Flash Memory 21 4 Toggle Bit D6 TMP89FM42 Note 1 Make sure that you set the C register to 0x00 LD FLSCR2 0xD5 ...
Страница 338: ...21 Flash Memory 21 4 Toggle Bit D6 TMP89FM42 ...
Страница 384: ...22 Serial PROM Mode 22 15 Revision History TMP89FM42 ...
Страница 388: ...24 Input Output Circuit 24 1 Control Pins TMP89FM42 ...
Страница 404: ...25 Electrical Characteristics 25 11 Revision History TMP89FM42 ...
Страница 406: ...26 Package Dimensions TMP89FM42 ...
Страница 408: ......