Amplifier Characteristics

Input impedance

Input bias current ............................................. ±80 pA

Input offset current

SCXI-1121.........................................................

±80 pA

SCXI-1122.........................................................

±80 pA

NMR (Normal Mode Rejection)

SCXI-1121......................................................... 60 dB (with 4 Hz filter enabled)

SCXI-1122......................................................... 60 dB (with 4 Hz filter enabled)

CMRR (Common Mode Rejection Ratio) (DC to 60 Hz)

Output range

SCXI-1121......................................................... ± 5 V

SCXI-1122......................................................... ± 10 V

Output impedance

Dynamic Characteristics

Multiplexer performance

System noise .................................................... See sccuracy table

Filter type ......................................................... 3-pole RC

Cutoff frequency (-3dB)

SCXI-1121......................................................... 4 Hz, 10 kHz (jumper selectable)

SCXI-1122......................................................... 4 Hz, 4 kHz (jumper selectable)

Stability

Excitation

Output Characteristics

Channels

SCXI-1121......................................................... 4 (voltage or current)

SCXI-1122......................................................... 2 (1 voltage and 1 current)

Bridge type ....................................................... Quarter, half, or full

Bridge completion

SCXI-1121......................................................... 4 (voltage or current)

SCXI-1122......................................................... 2 (1 voltage and 1 current)

Voltage Mode

Level

Drift................................................................... ±40 ppm/°C

Current drive

SCXI-1121 ........................................................ 28 mA per channel, (@ 3.333 V)

SCXI-1121......................................................... 14 mA per channel, (@ 10 V)

SCXI-1122......................................................... 225 mA

Current Mode

Level

Drift................................................................... ±40 ppm/°C

Maximum load resistance

SCXI-1121......................................................... 10 kΩ

SCXI-1122......................................................... 5 kΩ

Physical

Dimensions....................................................... 3.0 by 17.3 by 20.3 cm

(1.2 by 6.8 by 8.0 in.)

I/O connectors

Rear............................................................ 50-pin male ribbon cable rear connector

Front........................................................... 32-pin male DIN C connector

Environment

Operating temperature..................................... 0 to 50 ˚C

Storage temperature ........................................ -20 to 70 ˚C

Relative humidity ............................................. 5 to 90% noncondensing

Certification and Compliance

SCXI-1121/1122 ............................................... 250 V, Cat II working voltage

European Compliance

EMC ................................................................. EN 61326 Group I Class A, 10m,

Table 1 Immunity

Safety .............................................................. EN 61010-1

North American Compliance

EMC ............FCC Part 15 Class A using CISPR

Safety ............................................................... UL Listed to UL 3111-1

CAN/CSA C22.2 No. 1010.1

Australia & New Zealand Compliance

EMC ................................................................. AS/NZS 2064.1/2 (CISPR-11)

SCXI Isolated Universal Input Modules

305

National Instruments • Tel: (800) 433-3488 • Fax: (512) 683-9300 • info@ni.com • ni.com

Specifications

Module

Normal Powered On

Powered Off / Overload

SCXI-1121

1 GΩ

50 kΩ

SCXI-1122 (gain>1)

1 GΩ

100 kΩ

SCXI-1122 (gain<1)

1 MΩ

100 kΩ

Scan Interval (per channel, any gain setting)

Module

Filter Setting

SCXI-1121

All settings

5.2 µs

10 µs

20 µs

SCXI-1122

4 Hz

1 s

–

–

4 kHz

10 ms

–

–

Module

Excitation Level

Accuracy

SCXI-1121 (jumper selectable)

3.333 V

± 0.04%

10 V

± 0.2%

SCXI-1122

3.333 V

± 0.04%

Module

Filter

CMRR 50 or 60 Hz

SCXI-1121

4 Hz

160 dB

10 kHz

100 dB

SCXI-1122

4 Hz

160 dB

4 kHz

100 dB

Module

Gain Temperature Coefficient

Offset Temperature Coefficient

SCXI-1121

20 ppm/°C

(± 0.2 ± 200/gain) µV/°C

SCXI-1122 (gain≥1)

10 ppm/°C

(± 0.2 ± 150/gain) µV/°C

SCXI-1122 (gain<1)

25 ppm/°C

(± 0.2 ± 150/gain) µV/°C

Module

Multiplexed Mode

Parallel Mode

SCXI-1121

100 Ω

330 Ω

SCXI-1122

75 Ω

–

Module

Excitation Level

Accuracy

SCXI-1121 (jumper selectable)

0.15 mA

± 0.04%

0.45 mA

± 0.2%

SCXI-1122

1.0 mA

± 0.04%