Fluke 5790A Service Manual page 5

2-83. A/D Amplifier Assembly (A15) ....................................................... 2-37
2-84. Chopper Circuit............................................................................ 2-37
2-90. A/D Amplifier Circuits ................................................................ 2-39
2-96. Digital Control and Power Supply ............................................... 2-41
2-97. DAC Assembly (A16) ...................................................................... 2-41
2-98. DAC Assembly Reference Circuitry............................................ 2-42
2-99. Duty-Cycle Control Circuit.......................................................... 2-43
2-100. DAC Filter Circuit ....................................................................... 2-44
2-101. DAC Output Stage ....................................................................... 2-44
2-102. Sense Current Cancellation Circuit .............................................. 2-44
2-103. Linearity Control Circuit.............................................................. 2-44
2-104. Negative Offset Circuit ................................................................ 2-45
2-105. Wideband Module (A6, Option -03) ................................................ 2-45
2-106. Input Signal Path for the Upper Four Ranges .............................. 2-47
2-107. Input Signal Path for the Lower Four Ranges.............................. 2-47
2-108. DC Offset Feedback for Amplifier U3 (Lower Ranges).............. 2-48
2-109. RMS Sensor Circuit ..................................................................... 2-48
2-110. Transfer Methodology.................................................................. 2-48
2-111. DC Offset Feedback for the RMS Sensor Amplifier ................... 2-48
2-112. Range Comparator ....................................................................... 2-49
2-113. Wideband Frequency Counter...................................................... 2-49
2-114. Digital Control ............................................................................. 2-50
2-115. A6A2 Input Protection Module.................................................... 2-50
3 Calibration and Verification................................................................ 3-1
3-1. Introduction........................................................................................... 3-3
3-2. Calibration Cycle.............................................................................. 3-3
3-3. Periodic and Service Calibration ...................................................... 3-3
3-4. Full or Range Calibration ................................................................. 3-3
3-5. Automating Calibration and Verification ......................................... 3-3
3-6. How Calibration Memory is Organized ........................................... 3-4
3-7. How to Use the Calibration Menus .................................................. 3-5
3-8. The Cal Menu............................................................................... 3-5
3-9. Zero Cal Softkey .......................................................................... 3-6
3-10. See Cal Dates Softkey.................................................................. 3-6
3-11. Cal Reports Softkey ..................................................................... 3-6
3-12. Update Cal Dates Menu ............................................................... 3-6
3-13. Periodic Calibration .............................................................................. 3-7
3-14. Calibrating the Main Input ............................................................... 3-7
3-15. Characterizing the DC Source...................................................... 3-7
3-16. DC Calibration ............................................................................. 3-13
3-17. AC Calibration ............................................................................. 3-19
3-18. Calibrating the Wideband AC Option .............................................. 3-27
3-19. Characterizing the AC Source...................................................... 3-29
3-20. Calibrating Wideband Input Gain at 1 kHz.................................. 3-31
3-21. Calibrating Wideband Input Flatness........................................... 3-33
3-22. Service Calibration ............................................................................... 3-35
3-23. Xfer Offset Adjustment .................................................................... 3-39
3-24. Wideband Amplifier Rolloff Adjustment......................................... 3-40
3-25. Verification ........................................................................................... 3-43
3-26. Verifying the Main Input (INPUT 1 or 2) ........................................ 3-43
3-27. Verifying AC-DC Difference for Regions I and III
(220 mV through 1000 V Range)................................................. 3-48
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