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For safety, instruments and accessories must be used in accordance with the operating instructions. If the instruments or 

accessories are used in a manner not specified in the operating instructions, the protection provided by the equipment may be 

impaired. 
Do not exceed the maximum signal levels of the instruments and accessories. Maximum signal levels are defined in the 

specifications and operating information and shown on the instrument panels, test fixture panels, and switching cards. 
When fuses are used in a product, replace with the same type and rating for continued protection against fire hazard. 
Chassis connections must only be used as shield connections for measuring circuits, NOT as protective earth (safety ground) 

connections. 
If you are using a test fixture, keep the lid closed while power is applied to the device under test. Safe operation requires the use 

of a lid interlock. 

If a 

 screw is present, connect it to protective earth (safety ground) using the wire recommended in the user documentation. 

The 

 symbol on an instrument means caution, risk of hazard. The user must refer to the operating instructions located in the 

user documentation in all cases where the symbol is marked on the instrument. 

The 

 symbol on an instrument means warning, risk of electric shock. Use standard safety precautions to avoid personal 

contact with these voltages. 

The 

 symbol on an instrument shows that the surface may be hot. Avoid personal contact to prevent burns. 

The 

 symbol indicates a connection terminal to the equipment frame. 

If this 

 symbol is on a product, it indicates that mercury is present in the display lamp. Please note that the lamp must be 

properly disposed of according to federal, state, and local laws. 
The 

WARNING

 heading in the user documentation explains hazards that might result in personal injury or death. Always read 

the associated information very carefully before performing the indicated procedure. 
The 

CAUTION

 heading in the user documentation explains hazards that could damage the instrument. Such damage may 

invalidate the warranty. 

The 

CAUTION

 heading with the 

 symbol in the user documentation explains hazards that could result in moderate or minor 

injury or damage the instrument. Always read the associated information very carefully before performing the indicated 

procedure. Damage to the instrument may invalidate the warranty.  
Instrumentation and accessories shall not be connected to humans. 
Before performing any maintenance, disconnect the line cord and all test cables. 
To maintain protection from electric shock and fire, replacement components in mains circuits — including the power 

transformer, test leads, and input jacks — must be purchased from Keithley. Standard fuses with applicable national safety 

approvals may be used if the rating and type are the same. The detachable mains power cord provided with the instrument may 

only be replaced with a similarly rated power cord. Other components that are not safety-related may be purchased from other 

suppliers as long as they are equivalent to the original component (note that selected parts should be purchased only through 

Keithley to maintain accuracy and functionality of the product). If you are unsure about the applicability of a replacement 

component, call a Keithley office for information. 
Unless otherwise noted in product-specific literature, Keithley instruments are designed to operate indoors only, in the following 

environment: Altitude at or below 2,000 m (6,562 ft); temperature 0 °C to 50 °C (32 °F to 122 °F); and pollution degree 1 or 2. 
To clean an instrument, use a cloth dampened with deionized water or mild, water-based cleaner. Clean the exterior of the 

instrument only. Do not apply cleaner directly to the instrument or allow liquids to enter or spill on the instrument. Products that 

consist of a circuit board with no case or chassis (e.g., a data acquisition board for installation into a computer) should never 

require cleaning if handled according to instructions. If the board becomes contaminated and operation is affected, the board 

should be returned to the factory for proper cleaning/servicing. 
Safety precaution revision as of June 2017. 

Summary of Contents for 3761

Page 1: ...User s Manual 3761 900 01 Rev B January 2018 P3761 900 01B 3761 900 01B www tek com keithley Model 3761 10 Channel Low Current Multiplexer Card...

Page 2: ...s is strictly prohibited These are the original instructions in English All Keithley Instruments product names are trademarks or registered trademarks of Keithley Instruments Other brand names are tra...

Page 3: ...d to mains These instruments will be marked as category II or higher Unless explicitly allowed in the specifications operating manual and instrument labels do not connect any instrument to mains Exerc...

Page 4: ...lains hazards that could damage the instrument Such damage may invalidate the warranty The CAUTION heading with the symbol in the user documentation explains hazards that could result in moderate or m...

Page 5: ...nstallation 2 2 Web browser support 2 3 General operation 3 1 General operation 3 1 Safety hazards 3 1 Current and voltage switching applications 3 2 Operation considerations 4 1 Cables 4 1 External f...

Page 6: ...re 1 Model 3761 10 channel Low Current Multiplexer Card The 3761 has two output connectors which allow you to add additional cards Each additional card increases the capacity of the multiplexer by ten...

Page 7: ...nded warranty Additional years of warranty coverage are available on many products These valuable contracts protect you from unbudgeted service expenses and provide additional years of protection at a...

Page 8: ...http www tek com keithley General information General ratings for the 3761 are listed in the following table Category Specification Voltage rating 30 V Current rating 100 mA Input and output connecti...

Page 9: ...lified personnel Do not perform these procedures unless you are qualified Failure to recognize and observe standard safety precautions could result in personal injury or death due to electric shock Un...

Page 10: ...puts are located on the front of the card Figure 2 Model 3761 card connectors While SMA connectors are not typically used in low current applications the connectors on the 3761 are compact Teflon insu...

Page 11: ...last inch or so press in firmly to mate the card connector to the mainframe connector 5 On each side of the card there is a mounting screw Tighten these two screws to secure the card to the mainframe...

Page 12: ...and any unprotected leads wiring with double insulation for 500 volts Category I Follow these recommendations before and after applying power to the equipment 1 Do not exceed the 3761 maximum allowab...

Page 13: ...cations For current switching applications each channel on the 3761 has a pair of single pole single throw SPST normally open NO relays The relay pair switches signal HI between signal LO analog groun...

Page 14: ...a low impedance picoammeter When a channel is not selected for measurement the current path is maintained through that channel s analog grounding relay which is automatically updated with the channel...

Page 15: ...voltsampsmode to any value other than 0 or 1 will result in the following error 222 Parameter data out of range slot slot_3761 voltsampsmode 2 setting voltsampsmode on a card that does not support it...

Page 16: ...apacitance Charged capacitances in the circuit can cause excessive currents surge currents to flow through the relay contacts if the source is shorted out or if the output is switched to capacitive lo...

Page 17: ...nt Multiplexer Card User s Manual 4 2 3761 900 01 Rev B January 2018 High impedance measurements Because of the high impedance circuits on the 3761 this card contains no user serviceable components an...

Page 18: ...f the scanner card include Low offset current error 1 pA specified 30 fA typical Switching of AC or DC signals up to 100 mA SMA input and output connectors Two outputs for connecting multiple 3761 car...

Page 19: ...h up to 1 MHz Maximum switched and carry current and voltage levels are 100 mA and 30 V peak using resistive loads Direct measurement of capacitor leakage or insulation resistance If you want to measu...

Page 20: ...citor under test 3 When the capacitor is charged close the applicable channel of the 3761 to start the measurement The current is measured at IM as shown in the previous figure To maintain the voltage...

Page 21: ...esistance and an individual discharge resistor The discharge resistors are used to drain the electric charge from the capacitors when the test completes Using the indirect method the Model 3762 can be...

Page 22: ...rd from the outputs when all channels are open and closes when any channel closes This isolation relay configures itself automatically when assembling a test system using multiple 3761 cards The 3706A...

Page 23: ...Section 5 Typical applications Model 3761 10 Channel Low Current Multiplexer Card User s Manual 5 6 3761 900 01 Rev B January 2018 Figure 8 20 channel scanner system with two 3761 cards in ampere mode...

Page 24: ...xternal factors 4 1 G General information 1 3 General operation 3 1 H Handling precautions 2 1 High impedance measurements 4 2 I Indirect measurement of capacitor leakage or insulation resistance 5 2...

Page 25: ...names are the property of Keithley Instruments All other trademarks and trade names are the property of their respective companies Keithley Instruments Corporate Headquarters 28775 Aurora Road Clevel...

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