Chapter 8
405
ADC/Interface Section
A3 Assembly ADC Circuits
10.Set the detector mode to NORMAL.
11.Check that A3U509 pin 9 has pulses every 130
µ
s and U509 pin 7
has pulses every 667
µ
s (although pulse widths may be changing).
ADC ASM
Refer to function block F of A3 Interface Assembly Schematic Diagram
(sheet 2 of 6) in the
8560 E-Series Spectrum Analyzer Component Level
Informatio
n.
1. Press
PRESET
on the spectrum analyzer and set the controls as
follows:
Span ................................................................................. 0 Hz
Sweep time ........................................................................ 60 s
Detector mode .......................................................... SAMPLE
2. Check that HSTART_SRC (U504 pin 4) goes TTL high, causing
HHOLD (U506 pin 16) to go high 15
µ
s later.
3. Check that HSTART_ADC (U506 pin 15) goes TTL high 19
µ
s after
HSTART_SRC goes high.
4. HHOLD should stay TTL high for approximately 18
µ
s, and
HSTART_ADC should stay high for approximately 31
µ
s.
5. Check that LCMPLT (U504 pin 15) goes TTL low 12
µ
s after
HSTART_ADC goes high (12 bits at 1
µ
s per bit). LCMPLT indicates
that the successive approximation state machine (SASM) has
completed the ADC conversion.
6. Check that LDONE (U506 pin 19) goes TTL low approximately 2
µ
s
after LCMPLT goes low.
ADC
Refer to function block A of A3 Interface Assembly Schematic Diagram
(sheet 2 of 6) in the 8560 E-Series Spectrum Analyzer Component Level
Information.
The successive approximation state machine (SASM) consists of
A3U527 and A3U528. Upon the occurrence of HSTART_ADC, the
SASM successively toggles bits from high to low starting with the most
significant bit. The digital result is then converted to an analog current
in DAC U518 and compared with the SAMPLED VIDEO. If the DAC
current is too high, the output of U512 will be low, telling the SASM
that the "guess" was high and that the bit just toggled should remain
low. It then moves on to the next most significant bit until all 12 bits
have been "guessed" at. Each "guess" takes 1
µ
s (one cycle of
HBADC_CLK0), or 12
µ
s to complete a conversion. When the
conversion is completed, the SASM sets LCMPLT low. The bits are
written to the data bus by buffers U514 and U516.
Содержание 8564EC
Страница 17: ...25 1 General Information ...
Страница 37: ...47 2 Adjustment Diagnostic Software ...
Страница 55: ...Chapter 2 65 Adjustment Diagnostic Software 2 LO Frequency Figure 2 2 LO Frequency Adjustment Locations ...
Страница 57: ...Chapter 2 67 Adjustment Diagnostic Software 3 YTO FM Coil Figure 2 3 YTO FM Coil Adjustment Locations ...
Страница 77: ...89 3 Manual Adjustment Procedures ...
Страница 129: ...161 3a Manual Adjustment Procedures 3335A Source not Available ...
Страница 142: ...175 4 Assembly Replacement ...
Страница 151: ...184 Chapter4 Assembly Replacement Procedure 2 A1 Front Frame A18 LCD Figure 4 2 LCD Assembly Exploded View ...
Страница 163: ...Chapter 4 205 Assembly Replacement Procedure 5 A2 A3 A4 and A5 Assemblies Figure 4 10 Assembly Cables 2 of 3 ...
Страница 166: ...208 Chapter4 Assembly Replacement Procedure 5 A2 A3 A4 and A5 Assemblies Figure 4 14 GPIB and A1A1 W1 Cable Placement ...
Страница 168: ...210 Chapter4 Assembly Replacement Procedure 6 A6 Power Supply Assembly Figure 4 15 Power Supply Cover ...
Страница 176: ...226 Chapter4 Assembly Replacement A9 Input Attenuator Figure 4 22 A9 and A10 A12 Mounting Screws ...
Страница 179: ...Chapter 4 229 Assembly Replacement A11 YTO Figure 4 23 A11 Mounting Screws at Right Side Frame ...
Страница 183: ...Chapter 4 233 Assembly Replacement Procedure 8 A14 and A15 Assemblies Figure 4 25 A14 and A15 Assembly Cables ...
Страница 190: ...Chapter 4 243 Assembly Replacement Procedure 11 Rear Frame Rear Dress Panel Figure 4 29 A6 Power Supply Cover ...
Страница 194: ...Chapter 4 257 Assembly Replacement Procedure 13 A21 OCXO Figure 4 34 A21 OCXO Mounting Screws ...
Страница 196: ...259 5 Replaceable Parts ...
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Страница 224: ...303 6 Major Assembly and Cable Locations ...
Страница 228: ...Chapter 6 307 Major Assembly and Cable Locations Introduction Figure 6 2 Top View A2 and A3 Unfolded ...
Страница 229: ...308 Chapter6 Major Assembly and Cable Locations Introduction Figure 6 3 Top View A2 A3 A4 and A5 Unfolded ...
Страница 230: ...310 Chapter6 Major Assembly and Cable Locations Introduction Figure 6 5 Bottom View A15 Unfolded ...
Страница 231: ...Chapter 6 311 Major Assembly and Cable Locations Introduction Figure 6 6 Bottom View A15 and A14 Unfolded ...
Страница 233: ...314 Chapter6 Major Assembly and Cable Locations Introduction Figure 6 9 Rear View FL4 B1 BT1 A20 VGA Connector ...
Страница 234: ...315 7 General Troubleshooting ...
Страница 238: ...Chapter 7 319 General Troubleshooting Introduction Figure 7 2 Ribbon Cable Connections 1 of 3 ...
Страница 239: ...320 Chapter7 General Troubleshooting Introduction Figure 7 3 Ribbon Cable Connections 2 of 3 ...
Страница 242: ...Chapter 7 323 General Troubleshooting Introduction Figure 7 5 Service Cal Data Menu ...
Страница 271: ...352 Chapter7 General Troubleshooting Block Diagram Description Figure 7 6 Functional Sections ...
Страница 283: ...364 Chapter7 General Troubleshooting Block Diagram Description ...
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Страница 287: ...377 8 ADC Interface Section ...
Страница 291: ...Chapter 8 381 ADC Interface Section Introduction Figure 8 2 A3 Test Connector Pin Locations ...
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Страница 322: ...427 9 IF Section ...
Страница 356: ...Chapter 9 461 IF Section A5 IF Assembly Figure 9 13 Detailed IF Adjust Signature 5 ...
Страница 358: ...Chapter 9 463 IF Section A5 IF Assembly Figure 9 14 Noisy Signature Figure 9 15 Noise with Correct Shape ...
Страница 359: ...464 Chapter9 IF Section A5 IF Assembly Figure 9 16 Region B Amplitude Variation Figure 9 17 Region B Amplitude Offset ...
Страница 369: ...474 Chapter9 IF Section Cal Oscillator P O A4 Assembly Figure 9 21 Output Waveform 10 kHz Resolution Bandwidth ...
Страница 370: ...Chapter 9 475 IF Section Cal Oscillator P O A4 Assembly Figure 9 22 Output Waveform 3 kHz Resolution Bandwidth ...
Страница 371: ...476 Chapter9 IF Section Cal Oscillator P O A4 Assembly Figure 9 23 Output Waveform 1 kHz Resolution Bandwidth ...
Страница 372: ...Chapter 9 477 IF Section Cal Oscillator P O A4 Assembly Figure 9 24 Output Waveform 300 Hz Resolution Bandwidth ...
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Страница 379: ...487 10 Controller Section ...
Страница 394: ...521 11 Synthesizer Section ...
Страница 431: ...564 Chapter11 Synthesizer Section Unlocked Fractional N PLL Figure 11 8 VCO Bias Voltages for A14 Assemblies ...
Страница 447: ...Chapter 11 581 Synthesizer Section Sweep Generator Circuit Figure 11 11 Simplified Synthesizer Section ...
Страница 448: ...582 Chapter11 Synthesizer Section Sweep Generator Circuit Figure 11 12 Simplified A14 Assembly Block Diagram ...
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Страница 454: ...593 12 RF Section ...
Страница 475: ...614 Chapter12 RF Section A14 Frequency Control Assembly Figure 12 4 A7 LO Multiplier Amplifier Drive ...
Страница 489: ...628 Chapter12 RF Section A15 RF Assembly Figure 12 10 10 MHz TTL Reference at U304 Pin 13 ...
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Страница 492: ...633 13 Display Power Supply Section ...
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Страница 505: ...671 14 Component Level Information Packets ...
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