NEC 78K0S/KB1+ User Manual page 166

Notes 2. Be sure to set the FR2, FR1, and FR0, in accordance with the reference voltage so that Notes 3
and 4 below are satisfied.
Example When AV
3. Set the sampling time as follows.
• AV
REF
• AV
REF
• AV
REF
• AV
REF
4. Set the A/D conversion time as follows.
• AV
REF
• AV
REF
• AV
REF
• AV
REF
5. The operation of the comparator is controlled by ADCS and ADCE, and it takes 1
operation start to operation stabilization. Therefore, when ADCS is set to 1 after 1
has elapsed from the time ADCE is set to 1, the conversion result at that time has priority over
the first conversion result. If the ADCS is set to 1 without waiting for 1
first conversion data.
ADCS ADCE
0
0
1
ADCE
Comparator
ADCS
Note The time from the rising of the ADCE bit to the rising of the ADCS bit must be 1
Caution 1. The above sampling time and conversion time do not include the clock frequency error.
Select the conversion time taking the clock frequency error into consideration (an error
margin maximum of ±5% when using the high-speed internal oscillator).
166
CHAPTER 10 A/D CONVERTER
≥ 2.7 V, f
REF XP
• The sampling time is 11.0
μ
more and 100 s or less.
• Set FR2, FR1, and FR0 = 0, 1, 1 or 1, 1, 1.
μ
≥ 4.5 V:
1.0 s or more
μ
≥ 4.0 V:
2.4 s or more
≥ 2.85 V: 3.0 μ
s or more
μ
≥ 2.7 V:
11.0 s or more
≥ 4.5 V: μ
3.0 s or more and less than 100
μ
≥ 4.0 V:
4.8 s or more and less than 100
μ
≥ 2.85 V: 6.0
s or more and less than 100
μ
≥ 2.7 V:
14.0 s or more and less than 100
Table 10-2. Settings of ADCS and ADCE
0 Stop status (DC power consumption path does not exist)
1 Conversion waiting mode (only comparator consumes power)
×
Conversion mode
Figure 10-4. Timing Chart When Comparator Is Used
Comparator operating
Conversion
Conversion
operation
Note
longer to stabilize the internal circuit.
User's Manual U17446EJ3V1UD
= 8 MHz
μ
s or more and the A/D conversion time is 14.0
μ
s
μ
s
μ
s
μ
s
A/D Conversion Operation
Conversion
waiting operation
μ
μ
s or more
μ
s or longer, ignore the
Conversion stopped
μ
s or
s from
μ
s or