Quiescent current measurement

The CW-425 offers a simple possibility to obtain highly precise measurements of the no-load and working currents of devices. The CW-425 offers a total measurement range of ±150 A, divided into three measurement ranges. It is possible to switch from one measurement range to the other virtually seamlessly within a maximum of 2 µs during ongoing operations.

The measured values are transmitted via a CAN interface. Devices settings such as baud rate of the CAN bus and output transfer rate can easily be configured via CAN messages. It is possible to read in a description file (dbc file) in software tools to display the measured values. The insulation voltage of up to 1000 VDC between the measuring circuit and the control circuit offers sufficient protection for other devices in the control circuit. 

The module is available as a favourably priced top-hat rail version as well as in a rugged desktop housing that offers a higher protection class.

The CW-425 is destined for automated measurement of no-load and working currents of control units, for example in automotive environments. At the same time the CW-425 is an ideal supplement for our CW-300 series designed for test bench applications.


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  • Single device to measure no-load and working current
  • Measurement range from ±150 A
  • Accuracy of 0,04 % in lower measurement range
  • Dynamic, seamless changeover of measurement channels
  • Control via CAN bus
  • Top-hat rail housing and rugged desktop housing available

Current measurement channel

Quantity 1
Measuring range total ±150 A
Measuring range quiescent current ±100 mA
Deviation 0 µA to 10 mA 0,04 % ±2 digit (relative to 10 mA)  
Deviation 10 mA to 100 mA 0,06 % ±5 digit (relative to 100 mA)
Deviation 100 mA to 150 A 0,15 % relative to 150 A*
Series resistance and voltage drop 1 Ω to 100 mA, 700 µΩ from 100 mA
Resolution 1 µA
Connector Stud bold M8


Quantity 1
Type ISO 11898-2 (high-speed)
CAN protocol version 2.0 A
Data rate 500 kBit/s
Termination 120 Ω, optional activation via Jumper 
ID 16, CAN-ID conifugable via switch  
Output rate Up to 500 Hz
Connector Lemo EPG.1B.304 (for CAN-Bus and Power Supply)


switching time

Quiescent current to load current 1 µs, with positive current flow
Quiescent current to load current 30 ms, with negative current flow
Load current to quiescent current 30 ms

power supply

Supply voltage 9 VDC to 30 VDC
Current consumption 100 mA at 12 VDC
Galvanic isolation 1000 VDC (between measuring circuit and control)

Environmental conditions

Temperature range operation: 0 °C to +60 °C
Temperature range storage -20 °C to +70 °C
Relative humidity 35 % to 85 % non-condensing

General information

Housing: Robust desktop housing, 45 mm DIN-Top-hat rail holder optional
Dimensions (LxWxH): 126 mm x 110 mm x 35 mm
Weigth: 180 g

Factory Calibration

DAkkS-Calibration on request

*Data preliminary


Datasheet CW-425

Download (PDF)

Back to the Overview | CW-400 Series