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ManualsBrandsRENESAS ManualsMicrocontrollers, Microprocessors & QuartzesEmbedded microcontroller SSOP 16 8-Bit 10 MHz I/O number 9
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78K0/Ix2 CHAPTER 12 OPERATIONAL AMPLIFIER
R01UH0010EJ0500 Rev.5.00 408
Feb 28, 2012
12.4 Operation of Operational Amplifier
The operational amplifier has the following mode.
Single AMP mode
PGA (Programmable gain amplifier) mode
12.4.1 Single AMP mode
Operatio
nal amplifier has two input pins (the AMP- pin and the AMP+ pin) and one output pin (the AMPOUT pin), and
can be used as single-power supply amplifier that can be externally connected.
The amplified voltage can be used as an analog input of the A/D converter, because the AMPOUT pin is alternatively
used with analog input pin of the A/D converter.
The procedure for starting operation in single amplifier mode is described below.
<1> Use the ADPCn register to set the pins (AMP-, AMP+, AMPOUT) to be used in single amplifier mode as analog
inputs.
<2> Use the PMx register to set the pins (AMP-, AMP+, AMPOUT) to be used in single amplifier mode to input mode.
<3> Set (1) the OPAMPnE bit and enable operation in single amplifier mode.
Caution To use as an input of the A/D converter a voltage that has been amplified in single amplifier mode,
enable operation in single amplifier mode before selecting an analog input channel by using the ADS
register.
12.4.2 PGA (Programmable gain amplifier) mode
In this mode, the an
alog voltage input from the PGAIN pin is amplified within the microcontroller. The gain can be
selected from four types (4, 8, 16, 32).
The amplified voltage can be used as an analog input of the A/D converter.
The procedure for starting operation in PGA mode is described below.
<1> Use the ADPC0 register to set the pins (PGAIN) to be used in PGA mode as analog inputs.
<2> Use the PM2 register to set the pins (PGAIN) to be used in PGA mode to input mode.
<3> Use the AMP0VG0 and AMP0VG1 bits to select the gain (4, 8, 16, 32).
<4> Set (1) the PGAEN bit and enable operation in PGA mode.
Caution To use as an input of the A/D converter a voltage that has been amplified in PGA mode, enable
operation in PGA mode before selecting an analog input channel by using the ADS register.