Renesas RL78/G1H

RL78/G1H CHAPTER 13 A/D CONVERTER
R01UH0575EJ0120 Rev. 1.20 Page 281 of 920
Dec 22, 2016
Various A/D conversion modes can be specified by using the mode combinations below.
Trigger mode Software trigger Conversion is started by software.
Hardware trigger no-wait mode Conversion is started by detecting a hardware trigger.
Hardware trigger wait mode The power is turned on by detecting a hardware trigger while the system
is off and in the conversion standby state, and conversion is then started
automatically after the stabilization wait time passes. When using the
SNOOZE mode function, specify the hardware trigger wait mode.
Channel selection
mode
Select mode A/D conversion is performed on the analog input of one selected
channel.
Conversion operation
mode
One-shot conversion mode A/D conversion is performed on the selected channel once.
Sequential conversion mode A/D conversion is sequentially performed on the selected channels until
it is stopped by software.
Operation voltage
mode
Standard 1 or standard 2 mode Conversion is done in the operation voltage range of 2.7 V
≤ VDD ≤ 3.6 V.
Low voltage 1 or low voltage 2
mode
Conversion is done in the operation voltage range of 1.8 V
≤ VDD ≤ 3.6 V.
Select this mode for conversion at a low voltage. Because the operation
voltage is low, it is internally boosted during conversion.
Sampling time selection Sampling clock cycles:
7 f
AD
The sampling time in standard 1 or low voltage 1 mode is seven cycles
of the conversion clock (f
AD). Select this mode when the output
impedance of the analog input source is high and the sampling time
should be long.
Sampling clock cycles:
5 f
AD
The sampling time in standard 2 or low voltage 2 mode is five cycles of
the conversion clock (f
AD). Select this mode when enough sampling time
is ensured (for example, when the output impedance of the analog input
source is low).