HP Op Note 5955-6270 Scope Probes

8/3/2019 HP Op Note 5955-6270 Scope Probes

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E LETT PACKARD IAVO PROBESE DIVIDER)Models10017A10018A10040A10041A10042A

OPERATING NOTE/FEBRUARY 1980TRODUCTION.

2. Hewlett-Packard miniature oscilloscope probesignificantly reduce the problem of probing denselypopulated IC componen ts o r th e characteristicallyminute conductors on IC circuit boards (see figure 1).These small, l ight-weight probes allow measurementshat were previously very difficult, while reducinghe hazard of short ing. The probe body fits in th ehand as comfortably as a pencil, and th e needlepoint tip easily penetrates protective coatings forpositive contact. Two accessories that further simplifyand improve connection to dual in-line packages arehe IC grabber (MP7, supplied) and th e Ie test clipHP Model 10024A, available accessory).

3. Length of the probe body is 45 mm (1.78 in.)it h an outside diameter of 2.5 mm (0.10 in.). Evenith insulat ing sleeve MP6 installed, the probe bodi only 75 mm (2.95 in.) long with an outside diame er

of 3.3 mm (0.13 in.). Probe specifications ar e listedin table 1.

Figure 1. Use of Probe in IC Circuit TestingTable 1. Specifications

Probe Approximate Approximate Compensates ProbeModel Overall Length Propagation Scope Input CNo. Metres (Ft) Delay Input C (approx)

10017A 1.1 (3.6) 4 ns 9-14 pF 8 pF10018A 1.9 (6.2) 6.7 ns 9-14 pF 10 pF10040A 1.1 (3.6) 4 ns 20-30 pF 10 pF10041A 2.1 (6.9) 8 ns 20-26 pF 12 pF10042A 3.1 (10.2) 12 ns 20-24 pF 15 pF

INPUT R: 1 megohm VOLTAGE RATING VS FREQUENCYDIVISIO RATIO Maximum power capab il it y o f the probe resistive10:1 2% when operated into 1 megohm center conductor is shown in the volt age vs fre-quency curve (on page 2).

Operating Note Part No. 5955-6270Microfiche Part No. 5955-6271

PRINTED IN U.S.A.For more Information, Call Your Local HP Sale. Officeor, In U.S., Eut (201) 265-5000. Mldwe.t (312) 677-0400. South (404) 438-6181We.t (213) 877-1282. Or, write: Hewlett-Packard, 1501 PageMill Road, Palo Alto, California 94304. In Europe, Po.t Office Box 85, CH-1217 Meyrln 2, Geneva, Switzerland. In Japan, YHP, 1-59-1, Yoyogl, Shlbuya-ku, Tokyo, 151.


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Models 10017A, 10018A, 10040A, 10041A, 10042A

MP2ALLIGATOR CLIP

MP7GRABBER

Figure 2. Probe with Hook Tip or Grabber7. PROBE WITHOUT HOOK TIP OR GRABBER. Theprobe can be used for point-to-point probing by removing hook tip MPI or grabber MP7 from probe assemblyAI. Ground the probe by attaching snap-on groundlead MP3 or ground spring MP5 (see figure 3).

PROBEBODY(PART OF A1)

SUBMINIATURE PROBE(PART )

Verify that the ground spring is fullymounted so that probe tip is well exposed;otherwise, ground spring may short topoint being tested.

SPRI G TIP MP5 PROVIDES A VERY SHORT GROUND LEADFigure 3. Probe with Ground Spring

8. When using snap-on ground lead MP3, grip theknurled part of MP6 and unscrew th e MP6 barrelfar enough to cover the ground shield of assembly AI.Ground spring MP5 can be mounted with, or withoutMP6 installed. If MP6 is installed, screw the MP6bar re l into the probe body as fa r as possible. Thiswill expose the ground shield of assembly AI. Groundspring MP5 can be installed by twist ing it clockwiseover MP6.9. SUBMINIATURE MODE OF OPERATION. Size ofthe probe can be further reduced by removing MP6(tum knurled part counterclockwise), and pulling theprobe tip out o f the probe body (see figure 4).

MP6 INSULATING SLEEVE.:,p.J....:::{= ~

Figure 4. Probe in Subminiature ModeWARNING I

ELECTRICAL SHOCK HAZARD. Beforeusing probe in the subminiature mode ofoperation, be sure to read the warninggiven in paragraph 5.

10. When using IC Test Clip HP Model l0024A(available accessory), insert probe in the clip to contact an IC pin (see f igure 5). A ground plane isbui lt into t he tes t clip, and the ground path is completed through a ground pin that is inser ted in thetest clip position corresponding to th e ground of theIC under test. The test clip ground plane also contactsthe probe ground shield to eliminate the need for additional ground lines.

Be careful when using the subminiatureprobe because it could cause a short circuit if it is dropped onto the circuit.Page 3


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odels 1001 A 1001 A 10040A 10041A, 10042A

10017A-05-,05-77

Figure 5. Use of Probe with Model l0024A Ie TestClip11'. BA DWIDTH CONSIDERATIONS.12. The dominant probe limitation to the systembandwidth is its input capacitance, assuming that thehigh-frequency compensation adjustments have beenmade as outlined in paragraph 17. Displayed bandwidth of any measurement system using an oscillo-cope and probe is determined by:

a. Probe input capacitance.b. Source impedance (Z level of circuit beingprobed).c. Source bandwidth.d. Oscilloscope bandwidth.

Thus, each of the above factors should be consideredseparately whenever bandwidth is an important partof the measurement.

13. ADJUSTMENT PROCEDURE.14. The probe requires two adjustments: low-frequency an d high-frequency compensation. Low-frequency compensat ion is an operating adjustment.High-frequency compensat ion is accomplished periodically, according to maintenance schedules.15. LOW-FREQUENCY COMPENSATION. HewlettPackard oscilloscopes have a calibrator (square-wave)output sui table for low-frequency probe compensation. If the monitoring oscilloscope does not have suchPage 4

an output, use a square-wave generator set for approximately I-kHz output.16. To accomplish low-frequency compensation, proceed as follows:

a. Connect probe to oscilloscope.b. Connect probe tip to square-wave source (calibrator or square-wave generator).c. Adjust oscilloscope for stable display of squarewave.d. Adjust A2A1C1 ( through opening In coverA2MP2) for best square wave.

17. HIGH-FREQUENCY COMPENSATION. High-frequency compensation requires an external ;l10-kHzpulse generator (rise time ~ 0 . 5 ns, such as HP 1920A for 10017A and 10018A; r ise t ime ~ ns,' such as HP8082A - for 10040A, 10041A, and 10042A) with theoutput. terminated with a 50-ohm feedthrough (HPModell0l00C) an d a probe-tip to BNC adapter (HP PartNo. 1250-1454).18. The purpose of high-frequency compensation inprobes is to nullify probe rise time loss other thanthat added by the probe input capacitance. To accomplish high-frequency compensation, proceed as follows:

a. Using 50-ohm coaxial cable, connect pulsegenerator directly to channel A (channel B) inputconnector on oscilloscope. Terminate oscilloscope inputs into 50 ohms.

b. Verify that both channels of oscilloscope meettheir published rise time/perturbation specifications.

c. Set both channe l input s of oscilloscope forhigh-impedan'ce termination.d. Using 50-ohm feedthrough termination, con

nect pulse generator to channel A (channel B) inputof oscilloscope.

e. Repeat step b.f. Set oscilloscope input terminations as follows:

Channel A . . . . . . . . . . . . . . . . . . HI impedanceChannel B . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 50n

g. Connect equipment as shown in figure 6.NOTEThe change in rise time on channel B

when the probe is inserted in, or removedfrom, the probe tip to BNC adapter i s dueto loading by the probe input capacitances.


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OSCI LLOSCOPE PULSE GENERATORDModels 10017A, 10018A, 10040A, 10041A, 1

19. MAINTENANCE.20. Maintenance consists of cleaning, adjustand parts replacement. Disassemble only to the enecessary to accomplish repairs and parts rement. Disassembly for parts replacement is as fo

20 dBATTENUATOR

BNC TEE

a. Remove all accessories (MPI throughMP6 is removed by turning knurled part coclockwise).

b. Slide cover A2MP2 from compensatiosembly A2.

Figure 6. High-frequency Compensation Test SetupPROBE TIP TO BNCADAPTER (HP 1250-1454) 10042A-oot-o3-n c. Unsolder center conductor of probe cableboard A2AIR4.

h. Set oscilloscope controls as follows:VOLTS/DIV (both channels) . 6 div displayTRIGGER '.. . . . . . . . . . .. COMPDISPLAy. . . . . . . . . . . . . . . . . . . . . . . . . . . . . ALTTIME/DIV 10 ns

i. Remove probe cover A2MP2 by pressing downedges and sliding it off.

j. Set A2A1R1 and A2A1R2 fully counterclocke (see schematics in figure 7).k. Adjust A2A1R1 and A2A1R2 alternately inincrements until channei A and channel B wave

are similar.1. Replace probe cover A2MP2 and note any

ange in channel A waveform.m. Remove probe cover A2MP2.n. Readjust A2A1R1 and A2A1R2 to compensater probe cover influence.o. Replace probe cover A2MP2. Waveformsmatch.

d. Unscrew compensat ion assembly A2probe cable. It may be necessary to hold connnut AIMPI with a thin, 7/I6-inch, open-end wre

e. Unsolder lead between board assemblyand BNC connector A2J1.

f. Remove board assembly A2AI by remtwo nuts and screws.g. Remove BNC connector A2J1 by turnicounter.clockwise with a thin, 7/16-inch, opewrench.h. Reverse p r o c e d ~ e for reassembly.

21. REPLACEABLE PARTS.22. Replaceable parts are shown in figure 8.ordering a part, address the order to the neHP Sales/Service Office. Provide model numbthe probe and a complete descript ion of theincluding HP Part Number.23. ACCESSORIES AVAILABLE. The followingsories are available for use with these probes:

Probe Tip to BNC Adapter - HP Part No.1250-1454.IC Test Clip - HP Model 10024A.


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Models l0017A, lOO18A, lOO40A, lOO41A, lOO42A --------_.A1

OUTPUT

A2J1

A2f'-I I

I II L__ J I1 - 1

R1900K

-----..C1*

II

....-----INPUT - - ...,

Schematic -Model 10042A

TOASSEMBLYA1

IA2 - - ------ - -1 ~ -------- ----II

R475 500ON 10018A ONLY

II___________ - - _ - - - - __ ..J--------- -------- - ---_..

OUTPUT

10042A-G10-G5-77

Model A1C1*10017A 6 pF10018A 9 pF10040A 8 pF10041A 11 pF10042A 14 pF

Schematic Models 10017A, 10018A, 10040A, 10041A

Figure 7. SchematicsPage 6


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Models 10017A, 10018A, 10040A, lOO4lA, 10042A

10042A-G01-G5-nMP5r

A2Al( MODEL 10042A )

MP7

~

MP4

GRN VEL QRN RED

A2MPl A2MP3

A2Al(MODELS 10017A, 10040A,

AND 10041A)

A2MP2

A2Al( MODEL 10018A) MP8

~ - = - - - - = = - = = - - - - - > - . , , < ~ ~ ;~ ~ L

- : ~ ; : - . . ; . : ~MPl

ReferenceDesignation HP Part No. Oty Description

AlA1A1A1A1A2A2A2A2A2A2J1A2A1A2A1A2A1A2A1C1A2A1R1A2A1R2A2A1R3A2A1R3A2A1R4A2A1R4A2MPlA2MP2A2MP2

10017-6000110018-6000110040-6000110041-6000110042-6000110017-6210210018-6210110040-6210110041-6210110042-621011250-123310017-6650110017-6650110042-665010121-04912100-17880698-64302100-17882100-19860698-72090698-720410014-2010210014-2410210016-24101

ASSY, ATTENUATOR-CABLE (MODEL loo17A)ASSY, ATTENUATOR-CABLE (MODEL loo18A)ASSY, ATTENUATOR-CABLE (MODEL 10040A)ASSY, ATTENUATOR-CABLE (MODEL 10041A)ASSY, ATTENUATOR-CABLE (MODEL l0042A)ASSY, COMPENSATION (MODEL 1oo17A)ASSY, COMPENSATION (MODEL 10018A)ASSY, COMPENSATION (MODEL 10040A)ASSY, COMPENSATION (MODEL 10041A)ASSY, COMPENSATION (MODEL 10042A)CONNECTOR,BNCASSY, PC BOARD (MODELS 1oo17A, 10040A, 10041A)ASSY, PC BOARD (MODEL 1oo18A)ASSY, PC BOARD (MODEL 10042A)C:VAR CER 5-30 PFR:VAR METFLM 500 OHM 1/2WR:FXD METFLM 111 K OHM 1/8WR:VAR METFLM 500 OHM 1/2W (MODEL 10017A, 10018A,10040A, 10041A)R:VAR METFLM 1KOHM 112W (MODEL 10042A)R:FXD METFLM 75 OHM 2% 112W (MODEL l0018A)R:FXD METFLM 46.4 OHM 1% 1/8W (MODEL 10042A)CHASSISCOVER (MODELS loo17A, 1oo18A, l0040A, 10041A)COVER (MODEL 10042A)

ACCESSORIESMP1MP2MP3MP4MP4MP4MP4MP5MP6MP7MP8

10017-676025061-125810006-613015041-14845041-14855041-14865041-14871460-147610017-6230210017-695018710-1300

RETRACTABLE HOOK TIPALLIGATOR CLIPSNAP-ON GROUND LEADWIRE MARKER, GRNWIRE MARKER, YELWfRE MARKER, ORNWIRE MARKER, REDGROUND SPRINGINSULATING SLEEVEGRABBERALIGNMENTTOOLFigure 8. Replaceable Parts

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r------------- SAFETY

This product has been designed and tested according to International Safety Requirements. Toensure safe operation and to keep the product safe, the information, cautions, and warnings in thismanual must be heeded. Refer to Section I and the Safety Summary for general safety considerationsapplicable to this product.

CERTIFICATIONHewlett-Packard Company certifies that this product met its published specifications at the time ofshipment from the factory. Hewlett-Packard further certifies that its calibration measurements aretraceable to the United States National Bureau of Standards, to the extent allowed by the Bureau'scalibration facility, and to the calibration facilities of other International Standards Organizationmembers.

WARRANTYThis Hewlett-Packard product is warranted against defects in material and workmanship for a periodof one year from date of shipment. Duringthe warranty period, Hewlett-Packard Companywill, atitsoption, either repair or replace products which prove to be defective.For warranty service or repair, this product must be returned to a service facility designated by HP.However, warranty service for products installed by HP and certain other products designated byHPwill be performed at Buyer's facility at no charge within the HP service t ravel area. Outside HPservice t ravel areas, warranty service will be performed at Buyer's facility only upon HP's prioragreement and Buyer shall pay HP's round trip travel expenses.For products returned to HP for warranty service,Buyer shall prepay shipping charges to HP and HPshall pay shipping charges-t

HP Op Note 5955-6270 Scope Probes

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