www.DataSheet4U.com
CHAPTER 14 A/D CONVERTER
260
(2) Input range of ANI0 to ANI7
The input voltages of ANI0 to ANI7 should be within the specification range. In particular, if a voltage above AV
REF
or below AV
SS
is input (even if within the absolute maximum rating range), the conversion value for that channel
will be indeterminate. The conversion values of the other channels may also be affected.
(3) Noise countermeasures
In order to maintain 8-bit resolution, attention must be paid to noise on pins AV
REF
and ANI0 to ANI7. Since the
effect increases in proportion to the output impedance of the analog input source, it is recommended that a
capacitor is connected externally as shown in Figure 14-9 in order to reduce noise.
Figure 14-9. Analog Input Pin Disposition
(4) Pins ANI0/P10 to ANI7/P17
The analog input pins ANI0 to ANI7 also function as input/output port (PORT1) pins. Pins used as the analog
input should be specified to the input mode.
When A/D conversion is performed with any of pins ANI0 to ANI7 selected, be sure not to execute a PORT1 input
instruction while conversion is in progress, as this may reduce the conversion resolution.
Also, if digital pulses are applied to a pin adjacent to the pin in the process of A/D conversion, the expected
A/D conversion value may not be obtainable due to coupling noise. Therefore, avoid applying pulses to pins
adjacent to the pin undergoing A/D conversion.
(5) AV
REF
pin input impedance
A series resistor string of approximately 10 k
Ω
is connected between the AV
REF
pin and the AV
SS
pin.
Therefore, if the output impedance of the reference voltage source is high, this will result in parallel connection
to the series resistor string between the AV
REF
pin and the AV
SS
pin, and there will be a large reference voltage
error.
If there is a possibility that a noise level of
AV
REF
or higher or AV
SS
or lower may enter,
clamp with a small diode with V
F
(0.3 V or less).
V
DD
Reference
Voltage Input
C = 100 to 1000 pF
AV
REF
ANI0 to ANI7
V
DD
AV
DD
AV
SS
V
SS
Содержание 78011BGC AB8 Series
Страница 2: ...www DataSheet4U com 2 MEMO ...
Страница 8: ...www DataSheet4U com 8 MEMO ...
Страница 22: ...www DataSheet4U com 22 MEMO ...
Страница 30: ...www DataSheet4U com 30 MEMO ...
Страница 34: ...www DataSheet4U com 34 MEMO ...
Страница 62: ...www DataSheet4U com CHAPTER 2 OUTLINE µPD78014Y Subseries 62 MEMO ...
Страница 78: ...www DataSheet4U com CHAPTER 3 PIN FUNCTION µPD78014 Subseries 78 MEMO ...
Страница 94: ...www DataSheet4U com CHAPTER 4 PIN FUNCTION µPD78014Y Subseries 94 MEMO ...
Страница 170: ...www DataSheet4U com CHAPTER 7 CLOCK GENERATOR 170 MEMO ...
Страница 222: ...www DataSheet4U com CHAPTER 9 8 BIT TIMER EVENT COUNTER 222 MEMO ...
Страница 230: ...www DataSheet4U com CHAPTER 10 WATCH TIMER 230 MEMO ...
Страница 262: ...www DataSheet4U com CHAPTER 14 A D CONVERTER 262 MEMO ...
Страница 318: ...www DataSheet4U com CHAPTER 15 SERIAL INTERFACE CHANNEL 0 µPD78014 Subseries 318 MEMO ...
Страница 408: ...www DataSheet4U com CHAPTER 16 SERIAL INTERFACE CHANNEL 0 µPD78014Y Subseries 408 MEMO ...
Страница 446: ...www DataSheet4U com CHAPTER 17 SERIAL INTERFACE CHANNEL 1 446 MEMO ...
Страница 472: ...www DataSheet4U com CHAPTER 18 INTERRUPT FUNCTIONS AND TEST FUNCTION 472 MEMO ...
Страница 502: ...www DataSheet4U com CHAPTER 22 µPD78P014 78P014Y 502 MEMO ...
Страница 520: ...www DataSheet4U com CHAPTER 23 INSTRUCTION SET 520 MEMO ...