12 | Keysight | 34980A Multifunction Switch/Measure Unit - Data Sheet
Table 3. Multiplexer selection table—speciꢁcations and characteristics—continued
34921A
34922A
34923A
34924A
34925A
General characteristics
Relay life, typical
No load
100 M
10 M
100 k
100 M
10 M
100 k
1000 M
10 M
10 k
1000 M
10 M
10 k
Unlimited within FET banks
Unlimited within FET banks
Unlimited within FET banks
10 V, 100 ma
Rated load
Scanning speeds [7]
100 ch/sec
4 ms/4 ms
Yes
100 ch/sec
4 ms/4 ms
Yes
500 ch/sec
0.5 ms/0.5 ms
Yes
500 ch/sec
0.5 ms/0.5 ms
Yes
1000 ch/sec
0.25 ms/0.25 ms
Yes
Open/ close time, typical
Analog bus backplane connection
[1] DC or AC RMS voltage, channel-to-channel or channel-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] 50 Ω source, 50 Ω load, differential measurements verified with 4-port network analyzer (Sdd21)
[5] With input resistors bypassed. Bypassing resistors will reduce lifetime of relays. See the rated load relay life characteristics.
[6] Limited to 6 W of channel resistance power loss per module
[7] Speeds are for 2-wire ohms or DCV, 4 1/2 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] With input protection resistors: 2 x 100 Ω ±5%; 0.5W ; TC = ±200 ppm/°C. The series resistance of the 34923/24/25 limits the use of the 100 Ω range.
[12] Channel resistance is typically < 1.5 Ω but can go as high as 50 Ω when a channel is used in measurement applications with < 10 mA load current. 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 periods 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. Keysight recommends the use of 4-wire
Ohms for resistance measurements. For high accuracy voltage measurements, select the DMM input resistance setting of >10 G ohms to minimize the impact of relay
contact resistance.