Wavetek 39A Скачать руководство пользователя страница 14 | Manualshive

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Wavetek 39A Скачать руководство пользователя страница 14

Circuit Descriptions

General

The following sections should be read with reference to the block diagram and the circuit
diagrams.

Common

Remote

Control

GPIB/

RS232

Common

CPU

INT

TRIG

DC Offset

Sum Out

Control

DAC,s

Waveform

FPGA

Sync

Out

Trig Out From

Next Channel

Trig Out From

Previous Channel

Common

Hold In

Common

Cursor/

Marker

Out

Waveform
RAM

Lock Clock In/Out To
Other Channels

Trig Out

12 bit
DAC

Zero Crossing

Comparator

Attenuators

0-50dB
Attenuator

Attenuators

Main
Out

DC

Offset

Output

Amp

10MHz
Elliptic
Filter

Amp

Common
CLK
In/Out

10MHz

CLK

PLL

Common

Ext

Trig

Common

VCA
In

Common

SUM
In

SUM Out

From Previous

Channel

VCA
SUM

Amplitude
Control

Amp

Amp

Bessel
Filter

16MHz
Elliptic
Filter

Simplified Block Diagram

Principles of Operation

The instrument operates in one of two different modes depending on the waveform selected.
DDS mode is used for sine, cosine, haversine, triangle, sinx/x and ramp waveforms. Clock
Synthesis mode is used for square, pulse, pulse train, arbitrary and sequence.

In both modes the waveform data is stored in RAM. As the RAM address is incremented the
values are output sequentially to a Digital-to-Analogue Converter (DAC) which reconstructs the
waveform as a series of voltages steps which are subsequently filtered before being passed to
the main output connector.

The main difference between DDS and Clock Synthesis modes is the way in which the addresses
are generated for the RAM and the length of the waveform data.

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Содержание 39A

Страница 1: ...ietary to Wavetek and is provided solely for instrument operation and maintenance The information in this document may not be duplicated in any manner without the prior approval in writing from Wavetek Wavetek Datron Test and Measurement Division Hurricane Way Norwich Norfolk NR6 6JB U K Tel 44 1603 256600 Fax 44 1603 256688 ...

Страница 2: ...Table of Contents Specifications 2 Safety 10 Installation 11 General 12 Circuit Descriptions 13 Calibration 18 Parts List 21 Component Layouts 29 Circuit Diagrams 31 1 ...

Страница 3: ... 1 year Temperature Stability Typically 1 ppm ºC Output Level 2 5mV to 10Vp p into 50Ω Harmonic Distortion 0 1 THD to 100kHz 65dBc to 20kHz 50dBc to 1MHz 35dBc to 10MHz 30dBc to 16MHz Non harmonic Spurii 65dBc to 1MHz 65dBc 6dB octave 1MHz to 16MHz Square Range 1mHz to 16MHz Resolution 1mHz 4 digits Accuracy 1 digit of setting Output Level 2 5mV to 10Vp p into 50Ω Rise and Fall Times 25ns Triangle...

Страница 4: ...arately defined and the sequence repetition rate is set by the pulse train period Arbitrary Up to 100 user defined waveforms may be stored in the 256K point non volatile RAM Waveforms can be defined by front panel editing controls or by downloading of waveform data via RS232 or GPIB Waveform Memory Size 64k points per channel Maximum waveform size is 64k points minimum waveform size is 4 points Ve...

Страница 5: ...s channel next channel or trigger generator External from TRIG IN or remote interface Gate Start Stop Phase 360 settable with 0 1 resolution subject to waveform frequency and type Sweep Frequency sweep capability is provided for both standard and arbitrary waveforms Arbitrary waveforms are expanded or condensed to exactly 4096 points and DDS techniques are used to perform the sweep Carrier Wavefor...

Страница 6: ...s output when the trigger signal goes true and the next tone is output at the end of the current waveform cycle when the trigger signal goes true again FSK The tone is output when the trigger signal goes true and the next tone is output immediately when the trigger signal goes true again Using 2 channels with their outputs summed together it is possible to generate DTMF test signals Trigger Genera...

Страница 7: ...he 0 phase point Output Signal Level TTL CMOS logic levels from typically 50Ω Cursor Marker Out Adjustable output pulse for use as a marker in sweep mode or as a cursor in arbitrary waveform editing mode Can be used to modulate the Z axis of an oscilloscope or be displayed on a second scope channel Output Signal Level Adjustable from nominally 2V to 14V normal or inverted adjustable width as a cur...

Страница 8: ...er and TRIG IN on a slave to synchronise phase lock two separate generators INTER CHANNEL OPERATION Inter channel Modulation The waveform from any channel may be used to Amplitude Modulate AM or Suppressed Carrier Modulate SCM the next channel Alternatively any number of channels may be Modulated AM or SCM with the signal at the MODULATION input socket Carrier frequency Entire range for selected w...

Страница 9: ...60 degrees number of points whichever is the greater Phase Error All waveforms 10ns The signals from the REF IN OUT socket and the SYNC OUT socket can be used to phase lock two instruments where more than 4 channels are required Inter channel Triggering Any channel can be triggered by the previous or next channel The previous next connections can be used to daisy chain a trigger signal from a star...

Страница 10: ...130mm height 350mm width 2 and 4 channels 212mm rack single channel 335mm long Weight 7 2 kg 16 lb 2 and 4 channels 4 1kg 9lb 1 channel Power 230V 115V or 100V nominal 50 60Hz adjustable internally operating range 14 of nominal 100VA max for 4 channels 75VA max for 2 channel 40VA max for 1 channel Installation Category II Operating Range 5 C to 40 C 20 80 RH Storage Range 20 C to 60 C Environmenta...

Страница 11: ...d opening the covers or removal of parts except those to which access can be gained by hand is likely to expose live parts The apparatus shall be disconnected from all voltage sources before it is opened for any adjustment replacement maintenance or repair Any adjustment maintenance and repair of the opened instrument under voltage shall be avoided as far as possible and if inevitable shall be car...

Страница 12: ...oltage The correct mains fuse types are for 230V operation 250 mA T 250V HRC for 100V or 115V operation 500 mA T 250V HRC To replace the fuse disconnect the mains lead from the inlet socket and withdraw the fuse drawer below the socket pins Change the fuse and replace the drawer The use of makeshift fuses or the short circuiting of the fuse holder is prohibited Mains Lead When a three core mains l...

Страница 13: ...cover 2 The rear panel may be removed as follows Disconnect the grey ribbon cable from PJ6 on the GPIB PCB Invert the instrument and remove the three screws securing the rear panel and the nuts securing the 9 way RS232 connector to the rear panel The panel may now be tilted back to allow access If the panel is to be completely removed the connectors must be removed from PJ3 PJ7 PJ8 and PJ11 the bl...

Страница 14: ...nnel VCA SUM Amplitude Control Amp Amp Bessel Filter 16MHz Elliptic Filter Simplified Block Diagram Principles of Operation The instrument operates in one of two different modes depending on the waveform selected DDS mode is used for sine cosine haversine triangle sinx x and ramp waveforms Clock Synthesis mode is used for square pulse pulse train arbitrary and sequence In both modes the waveform d...

Страница 15: ... a phase accumulator is used to increment the phase On each clock cycle the phase increment which has been loaded into the phase increment register by the CPU is added to the current result in the phase accumulator the 12 most significant bits of the phase accumulator drive the lower 12 RAM address lines the upper 4 RAM address lines are held low The output waveform frequency is now determined by ...

Страница 16: ... If a key is down then one of the transistors Q6 Q13 will be on and the corresponding bits read from IC12 IC13 will be high The MPU decodes this to produce a key code which is passed to the software Multiple keys down are ignored IC10 provides the port decode signals for access to IC12 and IC13 The knob is connected directly to the FPGA IC10 This decodes the 4 states of the switches and increments...

Страница 17: ...er The inductors are factory set before board assembly and must not be adjusted L204 provides sinx x correction and is adjusted at initial calibration L205 L206 L207 and associated components form the 10MHz 7 stage elliptic filter The inductors are factory set before board assembly and must not be adjusted L208 provides sinx x correction and is adjusted at initial calibration L209 C252 and C253 fo...

Страница 18: ...ntegrated 10MHz voltage controlled crystal oscillator If an external clock is applied C48 is charged up via D5 blocking the internal clock Phase Locked Loop and VCO IC203 is a VCO tuned by varicap diodes D209 212 The range is 20MHz to 40MHz for square and arbitrary waveforms and fixed at 27 48779MHz in the DDS mode Comparator IC205 gives TTL output levels IC206 is a PLL IC and has internal divider...

Страница 19: ...cy will determine the accuracy of the generator s clock setting and should ideally be 1ppm Calibration Procedure The calibration procedure is accessed by pressing the calibration soft key on the UTILITY screen CALIBRATION SELECTED Are you sure password tests exit continue The software provides for a 4 digit password in the range 0000 to 9999 to be used to access the calibration procedure If the pa...

Страница 20: ...djustment and the rotary control fine adjustment Pressing next increments the procedure to the next step pressing CE decrements back to the previous step Alternatively pressing exit returns the display to the last CAL screen at which the user can choose to either save new values recall old values or calibrate again The first two displays CAL 00 and CAL 01 specify the connections and adjustment met...

Страница 21: ...r must send the CALADJ command repeatedly and read the dmm or frequency meter until the required result for the selected calibration step is achieved The CALSTEP command is then issued to accept the new value and move to the next step While in remote calibration mode very little error checking is performed and it is the controllers responsibility to ensure that everything progresses in an orderly ...

Страница 22: ... HEATSINK PCB MTG 38MM PLAIN SK200 FOR IC220 20670 0320 HEATSINK PCB MTG 50MM PLAIN SK2 3 4 5 20670 0340 HEATSINK TO220 CLIP ON 29DEG W SK8 22010 0610 BATTERY 3V LITH 20MM BUTTON BATT 22040 0920 BEAD FERRITE LEADED FB1 200 206 22042 0260 INDUCTOR 2 7UH L208 22042 0261 INDUCTOR 2 07UH BLK L205 22042 0262 INDUCTOR 2 0UH WHT L206 22042 0263 INDUCTOR 1 78UH GRN L207 22042 0271 INDUCTOR 1 545UH RED L20...

Страница 23: ... RES SM0805 68R0F W1 R247 250 272 277 23105 0820 RES SM0805 82R0F W1 R269 23105 1100 RES SM0805 100RF W1 R7 225 227 229 230 249 23105 1110 RES SM0805 110RF W1 R48 51 251 266 23105 1130 RES SM0805 130RF W1 R58 62 23105 1150 RES SM0805 150RF W1 R201 213 216 23105 1180 RES SM0805 180RF W1 R220 294 309 23105 1215 RES SM0805 215RF W1 R248 271 23105 1220 RES SM0805 220RF W1 R3 59 223 312 23105 1470 RES ...

Страница 24: ...23105 6100 RES SM0805 10M0F W1 R45 52 224 23202 0039 RES 3R90F W25 MF 50PPM R72 23202 0100 RES 10R0F W25 MF 50PPM R70 23202 0102 RES 10R2F W25 MF 50PPM R262 265 23202 1240 RES 240RF W25 MF 50PPM R40 23202 1750 RES 750RF W25 MF 50PPM R39 23202 2220 RES 2K20F W25 MF 50PPM R71 23206 0412 RES 41R2F W60 MF 50PPM R260 261 263 264 23206 1200 RES 200RF W60 MF 50PPM R256 259 23222 0047 RES 4R70J W33 MF FUS...

Страница 25: ... 264 266 280 282 285 286 23557 0658 CAP 100U 25V ELEC RE2 P2 5 C78 80 23557 0660 CAP 2200U 16V ELEC RE2 P5 C75 23557 0664 CAP 1000U 35V ELEC RE2 P5 C72 73 23557 0673 CAP 22U 35V ELEC RE2 P2 C7 202 231 23557 9122 CAP 4700U 16V ELEC RE2 P7 5 C74 23620 0242 CAP 22NJ 100V P E P5 C227 23620 0246 CAP 100NK 63V P E P5 C228 23620 0249 CAP 330NK 63V P E P5 C64 65 23620 0252 CAP 2N2K 63V P E P5 C226 25021 0...

Страница 26: ...160 0013 IC V REG 7815 TO220 IC30 27160 0020 IC V REG 7915 T0220 IC31 27160 0210 IC V REG LM337 TO220 IC33 27160 0460 IC V REG L4941BV IC32 34 27227 0510 IC SM 4051 IC28 27227 0940 IC SM 4094 IC18 19 27236 0520 IC SM 74HC4052 IC211 212 217 27236 0530 IC SM 74HC4053 IC213 214 27238 0000 IC SM 74HCT00 IC202 27238 0140 IC SM 74HCT14 IC11 21 27239 0000 IC SM 74HC00 IC22 27239 0320 IC SM 74HC32 IC14 15...

Страница 27: ...FIXING 20234 0027 SCREW M3 X 6 PNHDPZ ZPST KEYBOARD PCB FRONT PANEL BEZEL 20234 0040 SCREW M2 5 X 12MML PNHDPZ ZPST LCD FIXING 20612 0011 WASHER FIBRE M3 KEYBOARD PCB FRONT PANEL 20620 0010 CLIP ENCODER KNOB 22219 0090 SWITCH ROCKER DPST GREY 22573 0056 HEADER 16WAY STR SIL STD FOR DISPLAY 22575 0202 SKT 2W 156 20AWG YELLOW IDT MAIN PCB PJ200A PJ200B PJ7 22575 0204 SKT 4W 156 20AWG YELLOW IDT INTE...

Страница 28: ... OTHER ITEMS Part Number Description Position 10144 0007 CABLE COAX 50Ω 2 6MM RG316 U BNC TO PCB MAIN PJ202 20030 0266 WASHER M4 ZPST RUBBER FEET 20037 0301 WASHER M3 SHK PROOF I T ZPST CHASSIS F PANEL 20038 9501 WASHER M3 SPRING CHASSIS SPACERS PCB SPACERS FRONT PANEL 20062 0700 SCREW NO 6 X 3 8 RFLNGPZ ST AB CHASSIS REAR PANEL 20063 0010 SCREW NO6 X 3 8 NIB HDPZ ST AB CASE UPPER 20210 0101 NUT M...

Страница 29: ...L USA VERSIONS 22469 0203 SOLDER TERMINAL PIN 18 0223K DISPLAY CABLE 22575 0202 SKT2W 156 20AWG YELLOW IDT PJ3 7 11 12 200 ON MAIN 22575 0204 SKT4W 156 20AWG YELLOW IDT PJ13 ON MAIN 22575 0206 SKT6W 156 20AWG YELLOW IDT PJ8 ON MAIN 33171 0130 SPRING FOOT 33537 0900 CASE UPPER 33537 0910 CASE LOWER 43171 1430 CONN ASSY GPIB MAIN 20W 43171 2250 CONN ASSY DIS MAIN 34W 48584 0221 CONN ASSY RS232 PC SC...

Страница 30: ...Component Layouts Main Pcb 29 ...

Страница 31: ...Keyboard Pcb GPIB Pcb 30 ...

Страница 32: ...Circuit Diagrams 31 ...

Страница 33: ...Gpib Interface Pcb ...

Страница 34: ...Keyboard Pcb ...

Страница 35: ...Main Pcb Sheet 1 of 4 MPU and Interfaces ...

Страница 36: ...Main Pcb Sheet 2 of 4 Analogue Section ...

Страница 37: ...Main Pcb Sheet 3 of 4 Waveform FPGA and Memory ...

Страница 38: ...Main Pcb Sheet 4 of 4 Power Supplies ...

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