Theory Of Operation - Fluke 39 Service Manual

2-1. Introduction .......................................................................................... 2-3
2-2. Functional Block Description............................................................... 2-3
2-3. Circuit Operation.................................................................................. 2-5
2-4. Power-Up Sequence ......................................................................... 2-5
2-5. Normal Operation ............................................................................ 2-6
2-6. Circuit Descriptions.............................................................................. 2-6
2-7. Power Supplies................................................................................. 2-6
2-8. Power-On Circuit......................................................................... 2-6
2-9. VCC ............................................................................................. 2-6
2-10. -22 Volts ...................................................................................... 2-7
2-11. VEE.............................................................................................. 2-7
2-12. VDD............................................................................................. 2-7
2-13. VSS .............................................................................................. 2-7
2-14. VREF ........................................................................................... 2-7
2-15. Low Battery Detection................................................................. 2-8
2-16. Power Reset ................................................................................. 2-8
2-17. Input Conditioning ........................................................................... 2-8
2-18. Difference Amplifier (Voltage Input).......................................... 2-8
2-19. Protection Circuit (Current Channel) .......................................... 2-8
2-20. Gain Amplifier............................................................................. 2-8
2-21. Latch (U1).................................................................................... 2-8
2-22. Anti-Alias Filter........................................................................... 2-9
2-23. Level Shifter ................................................................................ 2-9
2-24. A/D Converters ................................................................................ 2-9
2-25. Digital Kernel................................................................................... 2-10
2-26. Digital Signal Processor (U2)...................................................... 2-10
2-27. Programmable Logic Device ....................................................... 2-10
2-34. SRAMs (U5,U6,U7) .................................................................... 2-13
2-35. EPROM (U4) ............................................................................... 2-13
2-36. EEPROM (U11)........................................................................... 2-13
2-37. Serial EEPROM (U22) ................................................................ 2-13
2-38. Keypad ............................................................................................. 2-13
2-39. Display ............................................................................................. 2-13
2-40. LCD Module................................................................................ 2-13
2-41. BackLight .................................................................................... 2-14

Theory of Operation

Title
Chapter 2
Page
2-1