upd78f9211grt2-jjg-a ETC-unknow, upd78f9211grt2-jjg-a Datasheet - Page 165

• Manufacturer Part Number: upd78f9211grt2-jjg-a
• Description: 8-bit Single-chip Microcontrollers
• Manufacturer: ETC-unknow

(8) Conversion results just after A/D conversion start
(9) A/D conversion result register (ADCR, ADCRH) read operation
(10) Internal equivalent circuit
The first A/D conversion value immediately after A/D conversion starts may not fall within the rating range if the
ADCS bit is set to 1 within 1
0. Take measures such as polling the A/D conversion end interrupt request (INTAD) and removing the first
conversion result.
When a write operation is performed to the A/D converter mode register (ADM) and analog input channel
specification register (ADS), the contents of ADCR and ADCRH may become undefined. Read the conversion
result following conversion completion before writing to ADM and ADS. Using a timing other than the above may
cause an incorrect conversion result to be read.
The equivalent circuit of the analog input block is shown below.
Table 9-3. Resistance and Capacitance Values (Reference Values) of Equivalent Circuit
Remarks 1. The resistance and capacitance values shown in Table 9-3 are not guaranteed
4.5 V ≤ V
2.7 V ≤ V
DD
DD
2. n = 0 to 3
3. R
V
≤ 5.5 V
< 4.5 V
DD
Figure 9-21. Internal Equivalent Circuit of ANIn Pin
values.
R
C
C
µ
ANIn
OUT
IN
OUT
IN
s after the ADCE bit was set to 1, or if the ADCS bit is set to 1 with the ADCE bit =
:
:
: Allowable signal source impedance
: Internal pin capacitance
Analog input equivalent resistance
Analog Input equivalent capacitance
CHAPTER 9 A/D CONVERTER
User’s Manual U16994EJ3V0UD
R
OUT
1 kΩ
1 kΩ
R
OUT
60 kΩ
3 kΩ
R
IN
LSI internal
C
OUT
R
IN
C
8 pF
8 pF
OUT
C
IN
15 pF
15 pF
C
IN
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