Datasheet

SWITCHING AND CONTROL
A Greater Measure of Confidence
www.keithley.com
1.888.KEITHLEY
(U.S. only)
MULTIPLEXER CONFIGURATION: Two independent 1×20
2-pole multiplexers. Banks can be connected together via
relay creating a single 1×40 multiplexer. Banks can be iso-
lated from the backplane by relays. Card can be configured
for common side Ohms measurement via backplane relays.
Channel 41–42: Multiplex one of two 2-pole current signals
into DMM.
CONTACT CONFIGURATION: 2 pole form A.
CONNECTOR TYPE: Two 50 pin male D-shells. Removable
screw terminal option.
MAXIMUM SIGNAL LEVEL: Channels 1–40: 300V DC or RMS,
2A switched (3A carry), 60W, 125VA maximum. Channels
41–42: 60V DC or 30V RMS, 3A switched, 60W, 125VA maxi-
mum. Fused 3A, 250V RMS.
COMMON MODE VOLTAGE: Channels 1–40: 300V DC or RMS
between any terminal and chassis.
VOLT-HERTZ LIMIT: 8×10
7
.
CONTACT LIFE: >10
5
operations at maximum signal level. >10
8
operations no load.
1
TYPICAL SCANNING SPEEDS:
Switch Only
4
: Sequential scanning, single channel, immedi-
ate trigger advance: >120 ch/s.
With Measurements Into Memory
5
:
DCV (10V range) or 2W Ohms (1kW range): >110 ch/s
Thermocouple: >110 ch/s.
3- or 4-Wire RTD: >100 ch/s.
4-Wire Ohms (1kW range): >100 ch/s.
ACV (10V, 400Hz range) or ACI (1A, 400Hz range): >110 ch/s.
Dual
1×20
3
Single
1×40
2, 3
Channel Resistance
(end of contact life)
<1.0 W <1.5 W
Contact Potential
(differential)
<±1 µV <±3 µV
Offset Current
<±250 pA <±250 pA
Isolation
Differential
10
9
W, 280 pF 10
9
W, 530 pF
Bank-Bank
10
11
W, 60 pF
—
Channel-channel
10
9
W, 50 pF 10
9
W, 50 pF
Common Mode
10
9
W, 180 pF 10
9
W, 480 pF
Crosstalk Channel-channel
300kHz
<–60 dB <–60 dB
1MHz
<–50 dB <–50 dB
20MHz:
<–25 dB <–15 dB
Bandwidth
28 MHz 9 MHz
GENERAL
ACTUATION TIME: 4ms.
TEMPERATURE ACCURACY using Automatic CJC with
3721-ST accessory: 1°C for J, K, T, and E types (see
mainframe specification for details).
RELAY TYPE: Latching electromechanical.
RELAY DRIVE SCHEME: Direct.
INTERLOCK: Backplane relays disabled when interlock
connection is removed.
OPERATING ENVIRONMENT: Specified for 0° to 50°C.
Specified to 70% R.H. at 35°C.
STORAGE ENVIRONMENT: –25° to 65°C.
WEIGHT: 2.25 lbs.
SAFETY: Conforms to European Union Directive
73/23/EEC, EN61010-1.
EMC: Conforms to European Union Directive
2004/108/EC, EN61326-1.
NOTES
1. Open detector enabled during thermocouple measurements. Minimum
signal level 10mV, 10µA.
2. 3706A mainframe with all DMM backplane relays disconnected.
Maximum two card backplane relays closed.
3. Connections made using 3721-ST accessory.
4. Scanning script local to 3706A mainframe, within same bank, and
break before make switching.
5. 3706A mainframe with autorange off, limits off, dmm.autozero=0,
dmm.autodelay=0, 4½ digits (NPLC=0.006), for ACV dmm.detec-
torbandwidth=300, for OHMs dmm.offsetcompensation=off, dmm.
opendetector=off. Scanning script local to mainframe, sequential scan
within same bank (2 pole) or card (4 pole), and break before make
switching.
HI
LO
HI
LO
HI
LO
HI
LO
HI
LO
HI
LO
HI
LO
Output 1
HI
LO
Channel 1
HI
LO
Channel 20
Channels 2–19
Multiplexer Bank 1
Analog
Backplane 1
(DMM Input)
Analog
Backplane 2
(DMM Sense)
Analog
Backplane 3
Analog
Backplane 4
Analog
Backplane 5
Analog
Backplane 6
HI
LO
HI
LO
HI
LO
HI
LO
HI
LO
HI
LO
HI
LO
Output 2
HI
LO
Channel 21
HI
LO
Channel 40
Channels 22–39
Multiplexer Bank 2
Analog
Backplane 1
(DMM Input)
Analog
Backplane 2
(DMM Sense)
Analog
Backplane 3
Analog
Backplane 4
Analog
Backplane 5
Analog
Backplane 6
To Series 3700A Mainframe Analog Backplane
HI
LO
Channel 41
3A
HI
LO
Channel 42
3A
Amps
Analog
Backplane 1
(DMM Input LO)
LO
LO Sense
HI
LO
Channel 1
HI
LO
Channel 20
Channels 2–19
Multiplexer Bank 1
DMM
To Series 3700A Mainframe Analog Backplane
4 Wire
Common Side
Ohms
LO
LO Sense
HI
LO
Channel 21
HI
LO
Channel 40
Channels 22–39
Multiplexer Bank 2
DMM
HI
HI Sense
HI
HI Sense
Common
DMM
Two pole mode
Four-wire common side ohm mode
3721
Dual 1×20 Multiplexer Card
40 differential channels, automatic CJC w/3721-ST accessory
100% duty
50% duty
25% duty
10% duty
5% duty
1 shot
20
10
1
0.1 110100
Pulse Width (ms)
1. Model 3706A ambient temperature <28°C.
2. One shot repetition rate > 10 seconds.
3. Signal path routed only through one card (not through backplane).
4. Only one channel closed at a time.
5. Contact life specification unaffected if pulse width and carry current are not exceeded.
Maximum Carrying Current (A)
Maximum Carrying Current for Pulses
1000 10000
Model 3721 specifications Model 3721 specifications