Operation Description; Clock Supply; Voltage Input; Opamp Function Control - Toshiba TXZ Series Reference Manual

3. Operation Description

3.1. Clock supply

When you use OPAMP, please set an applicable clock enable bit to "1" (clock supply) in Clock supply and stop
register A for fsys ([CGFSYSENA], ([CGFSYSMENA])or Clock supply and stop register B for fsys
([CGFSYSENB], [CGFSYSMENB]), and Clock supply and stop register for fc ([CGFCEN]). An applicable
register and the bit position vary according to a product. Therefore, the register may not exist with the product.
Please refer to "Clock Control and Operation Mode" of the reference manual for the details.

3.2. Voltage Input

OPAMP is a differential input type, making it less susceptible to wiring noise etc. Enter the voltage both ends of
the shunt resistor that detects the motor current.

3.3. OPAMP function control

By setting the OPAMP control register [AMPCTLx] <AMPEN> = 1 (valid), the OPAMP function is enabled.
By setting the OPAMP control register [AMPCTLx] <AMPEN> = 0 (invalid), the input to the amplifier + side
(AINxP terminal) is bypassed and output from AMPOUTx. After reset, [AMPCTLx] <AMPEN> = 0 (invalid).
If you do not use an OPAMP, such as using an external connection amplifier, it can also be used as a normal
analog input by bypassing the OPAMP.

3.4. Gain control

The OPAMP can set the gain of 12 steps. Set the gain with the OPAMP control register [AMPCTLx]
<AMPGAIN[3: 0]>.
Magnification ratios that can set the gain are 2, 2.5, 3, 3.5, 4, 4.5, 6, 7, 8, 10, 12 and 15.

3.5. Voltage Output

When using the OPAMP, the voltage amplified with the gain set magnification is output.
The output of the OPAMP is output to the ADC.
When bypassing the OPAMP, the analog input is directly connected to the ADC.
2018-05-08
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TXZ Family
Operational Amplifier
Rev. 2.0