10

Table 3.

Multiplexer selection table—specifications and characteristics

34921A

34922A

34923A

34924A

34925A

Channels/configurations

402-wire

702-wire

801-wire

702-wire

801-wire

20 4-wire

35 4-wire

40 2-wire

35 4-wire

40 2-wire

4-current

20 4-wire

20 4-wire

1.5 A Fused

Switch type

Armature

Armature

Reed

Reed

Optically

latching

latching

isolated FET

Input characteristics (per channel)

Max volts

± 300 V

[1]

± 300 V

[1]

± 150 V peak

[2]

± 150 V peak

[2]

± 80 V peak

[2]

Maxcurrent(DC,ACRMS)

Switch current

1 A

1 A

0.5 A

0.5 A

0.02 A

[8]

Carry current

2 A

2 A

1.5 A

1.5 A

Power (W, VA)

[6]

60 W

60 W

10 W

10 W

1.6 W

Volt-Hertz limit

Initial closed channel res

[3][12]

<1.5Ω

<1.5Ω

< 1.5 Ω

< 1.5 Ω

<700Ω

nominal

nominal

General specifications

Offset voltage

[3]

< 3 uV

< 3 uV

< 50 uV

< 50 uV

< 3 uV

< 100 uV 1-wire

DCIsolation(ch-ch,ch-earth)

>10GΩ

>10GΩ

>10GΩ

>10GΩ

>10GΩ

N/A

N/A

N/A

N/A

T/C cold junction accuracy

[3, 10]

<1°C

N/A

N/A

N/A

N/A

AC characteristics

45 MHz

25 MHz

45 MHz

25 MHz

1 MHz

10 MHz 1-wire

Crosstalk at terminal block (ch-ch)

[4]

300kHz

-75dB

-75dB

-75dB

-75dB

Notrecommendedfor

RFsignalswitching

1MHz

-75dB

-75dB

-75dB

-70dB

20MHz

-50dB

-50dB

-50dB

-45dB

45MHz

-40dB

-40dB

Capacitance at terminal block

HI-LO

150pF

250pF

130pF

200pF

100pF

LO–earth

150pF

200pF

120pF

170pF

300pF(600pF1-wire)

[1]

DCorACRMSvoltage,channel-to-channelorchannel-to-earth

[2] Peak voltage, channel-to-channel or channel-to-earth

[3] Into analog bus. System errors are included in the internal DMM measurement accuracy specifications

[4] 50Ωsource,50Ωload,differentialmeasurementsverifiedwith4-portnetworkanalyzer(Sdd21)

[5] Withinputresistorsbypassed.Bypassingresistorswillreducelifetimeofrelays.Seetheratedloadrelaylifecharacteristics.

[6] Limitedto6Wofchannelresistancepowerlosspermodule

2

digits, delay 0, display off, autozero off, and within bank

[8] DC or peak AC current

[9] Ambient temperature < 30°C

[10] Includes 0.5°C temperature reference sensor and 0.5°C terminal block isothermal gradient error, measured under worst case loading of the mainframe; see User’s

Guide for information on supported external reference sensors

[11]Withinputprotectionresistors:2x100Ω±5%; 0.5W; TC=±200ppm/°C.Theseriesresistanceofthe34923/24/25limitstheuseofthe100Ωrange.

[12]Channelresistanceistypically<1.5Ωbutcangoashighas50Ωwhenachannelisusedinmeasurementapplicationswith<10mAloadcurrent.Increased

relay channel resistance for measurements with load currents below 10 mA can occur on cards that have been out of service or following relay inactivity for peri-

ods of greater than 1 week. Switching relays for 2K cycles prior to use may reduce the variation in channel resistance. Applies to the 34921A and 34922A. Agilent

recommendstheuseof4-wireOhmsforresistancemeasurements.Forhighaccuracyvoltagemeasurements,selecttheDMMinputresistancesettingof>10G

ohms to minimize the impact of relay contact resistance.