Theory Of Operation - Fluke 8842A Instruction Manual

5-1. INTRODUCTION................................................................................ 5-3
5-2. OVERALL FUNCTIONAL DESCRIPTION ...................................... 5-3
5-3. DETAILED CIRCUIT DESCRIPTION .............................................. 5-4
5-4. DC SCALING ...................................................................................... 5-4
5-5. VDC Scaling .................................................................................... 5-6
5-6. VDC Protection................................................................................ 5-7
5-7. mA DC Scaling ................................................................................ 5-7
5-8. Analog Filter .................................................................................... 5-7
5-9. TRACK/HOLD CIRCUIT ................................................................... 5-8
5-10. Track Configuration ......................................................................... 5-10
5-11. Settling Configuration...................................................................... 5-11
5-12. Hold Configuration .......................................................................... 5-11
5-13. Pre-Charge Configuration ................................................................ 5-11
5-14. PRECISION VOLTAGE REFERENCE.............................................. 5-11
5-15. OHMS CURRENT SOURCE .............................................................. 5-12
5-16. OHMS PROTECTION......................................................................... 5-13
5-17. OHMS FUNCTIONS ........................................................................... 5-13
5-18. 2-Wire Ohms.................................................................................... 5-13
5-19. 4-Wire Ohms.................................................................................... 5-15
5-20. A/D CONVERTER .............................................................................. 5-15
5-21. Timing/Data Control ........................................................................ 5-17
5-22. Precision DAC ................................................................................. 5-17
5-23. A/D Amplifier .................................................................................. 5-18
5-24. Bootstrap Supplies ........................................................................... 5-18
5-25. DISPLAY ............................................................................................. 5-18
5-26. KEYBOARD........................................................................................ 5-19
5-27. DIGITAL CONTROLLER................................................................... 5-19
5-28. In-Guard Microcomputer ................................................................. 5-21
5-29. Function and Range Control ............................................................ 5-23
5-30. A/D Control and Computation ......................................................... 5-23
5-31. Calibration Correction...................................................................... 5-23
5-32. Keyboard/Display Control ............................................................... 5-24
5-33. Troubleshooting Modes ................................................................... 5-24
5-34. Guard-Crossing Communication ..................................................... 5-24
5-35. GUARD CROSSING ........................................................................... 5-24

Theory of Operation

Title
Chapter 5
Page
5-1