ADCMT 6166 - Voltage Limit Error at Current Source

6166 DC Voltage Current Source Operation Manual
5.5.2 Voltage Limit Error at Current Source
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5.5.2 Voltage Limit Error at Current Source
The voltage limit detection method for current source adopted by the 6166 increases errors at lower limit
values.
VL: Voltage limit detection (Voltage limit value)
Vo: Voltage across load (Is • ERL)
Is: Source current
Rs: Reference resistance 1 mA range: 4.17 k
10 mA range: 410 
100 mA range 40 
VL = Vo + Is • Rs
Thus, the actual clamp voltage across the load Vo is obtained by the following formula.
Vo VL - Is • Rs
Error term
Limit value
Is • Rs is the error term.
e.g. VL = 10 V
Is = 1 mA (1 mA range)
RL = 20 k
Under the above conditions, the clamp voltage is obtained as follow:
Vo = 10 V - (1 mA  4.17 k ) = 5.83 V
(Error: 10 V - 5.83 V = 4.17 V)
Voltage
limit
detection
Load