Fujitsu Semiconductor (Shanghai) Co., Ltd.
Operational Amplifier Version 1.0 Revision History Revision History Date 2010-03-22 Author Folix Change of Records V1.0, First draft This manual contains 18 pages. 1. The products described in this manual and the specifications thereof may be changed without prior notice. To obtain up-to-date information and/or specifications, contact your Fujitsu sales representative or Fujitsu authorized dealer. 2.
Operational Amplifier Version 1.0 CONTENTS CONTENTS Revision History .......................................................................................................................... 2 Table of Contents........................................................................................................................ 3 1 Introduction .......................................................................................................................... 4 2 Amplifier Overview .............
Operational Amplifier Version 1.0 Chapter 1 Introduction 1 Introduction In this document, we will introduce how to use the amplifier function on the MB95F430 series. Chapter 2 gives an overview on operational amplifier. Chapter 3 introduces the operations of operational amplifier. Chapter 4 introduces Operational Amplifier setting procedure. Chapter 5 introduces amplifier drivers. Chapter 6 introduces amplifier application demo.
Operational Amplifier Version 1.0 Chapter 2 Amplifier Overview 2 Amplifier Overview The operational amplifier can be used to sense the ground current, and support front-end analog signal conditioning prior to A/D conversion. It can operate in either closed loop mode or standalone open loop mode. ■ Closed Loop Mode The operational amplifier can be configured as a non-inverting closed loop operational amplifier.
Operational Amplifier Version 1.0 Chapter 2 Amplifier Overview 2.1 Block Diagram of Operational Amplifier Figure 1 Block Diagram of Operational Amplifier 2.2 Pins of Operational Amplifier The OPAMP uses the OPAMP_P pin and the OPAMP_N pin as the analog input pins of the operational amplifier, and uses the OPAMP_O pin as the analog output pin of the operational amplifier. When GS [5] is set to "1B" and GS [4:0] is set to "00000B", the OPAMP will work as a standalone open loop operational amplifier.
Operational Amplifier Version 1.0 Chapter 2 Amplifier Overview 2.3 OPAMP Control Register The OPAMP control register (OPCR) is used to turn on and off the OPAMP, to enable and disable OPAMP analog output, and to enable and disable OPAMP analog input. The register can also be used to set the OPAMP to operate as a standalone open loop operational amplifier, or a non-inverting closed loop operational amplifier with six different closed loop gain settings that can be selected by the software.
Operational Amplifier Version 1.0 Chapter 2 Amplifier Overview ■ Functions of Bits in OPAMP Control Register (OPCR) ■ OPAMP Operating Mode Settings Notes: •While the OPAMP is operating, modifying the settings of RES2, RES1 and RES0 is allowed, however, do not use the output signal of the OPAMP or execute A/D conversion until OPAMP output becomes stable. •It is recommended to turn off the operational amplifier before modifying the settings of RES2, RES1 and RES0.
Operational Amplifier Version 1.0 Chapter 3 Operations of Operational Amplifier 3 Operations of Operational Amplifier The operational amplifier can be activated by setting the PD bit in the OPCR register using the software. It can operate in closed loop mode or open loop mode, depending on the settings of the RES2, RES1 and RES0 bits in the OPCR register. ■ Activating Operational Amplifier by Software The settings shown in Figure 24.
Operational Amplifier Version 1.0 Chapter 4 Amplifier setting procedure 4 Amplifier setting procedure Below is an example of procedure for setting the operational amplifier. ● Initial settings 1) Set both OPCR: OPID and OPCR: OPOD to "0" to enable both OPAMP analog input and OPAMP analog output. 2) Set the feedback resistor and RES [2:0] in OPCR. 3) Set OPCR: PD to "0" to turn on the operational amplifier. 4) Wait until the operation amplifier stabilizes. 5) Start A/D conversion if necessary.
Operational Amplifier Version 1.0 Chapter 5 Amplifier Driver 5 Amplifier Driver This is OPAMP driver description. 5.1 Peripheral Usage The MCU pins used as below: OPAMP_N,used as amplifier negative input; OPAMP_P,used as amplifier positive input; OPAMP_O,used as amplifier output; 5.2 Driver Code 5.2.
Operational Amplifier Version 1.0 Chapter 5 Amplifier Driver 5.2.2 Amplifier Routine void AmpOpenLoop() Return Parameters Description Example : none. : none. : open-loop setting. : AmpOpenLoop(); void AmpOpenLoop() { DDR6_P60=0; DDR6_P61=0; DDR6_P62=1; OPCR=0x60;//Amplifier gain is R3/R1 } void AmpCloseLoop() Return Parameters Description Example : none. : none. : close-loop setting.
Operational Amplifier Version 1.0 Chapter 6 Typical Application 6 Typical Application This is the typical application introduction. 6.1 HW Design In this application, we will test the operational amplifier in the MB95F430K. The HW is designed as below. The R1, R2, R3 is used in open-loop amplifier. Figure 4 Hardware Design 6.2 Sample Code void main(void) Return : none. Parameters : none; Description : system main programm.
Operational Amplifier Version 1.0 Chapter 7 More Information 7 More Information For more Information on FUJITSU Semiconductor products, visit the following websites: English version: http://www.fujitsu.com/cn/fsp/services/mcu/mb95/application_notes.html Simplified Chinese Version: http://www.fujitsu.com/cn/fss/services/mcu/mb95/application_notes.
Operational Amplifier Version 1.0 Chapter 8 Appendix 8 Appendix Figure 1 Block Diagram of Operational Amplifier ................................................................................ 6 Figure 2 OPAMP Control Register......................................................................................................... 7 Figure 3 Settings for Activating Operational Amplifier ........................................................................ 9 Figure 4 Hardware Design ......................
Operational Amplifier Version 1.0 Chapter 9 Sample Code 9 Sample Code main.c #include "mb95430.h" #include "TypeDef.
Operational Amplifier Version 1.
Operational Amplifier Version 1.
