Agilent Technologies E3646A, User Manual, Page: 37 / 211

Chapter 2 General Information
Output Connections
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2
Stability
Using remote sensing under certain combinations of load lead lengths and large load
capacitances may cause your application to form a filter, which becomes part of the
voltage feedback loop. The extra phase shift created by this filter can degrade the
power supply’s stability, resulting in poor transient response or loop instability. In
severe cases, it may cause oscillations. To minimize this possibility, keep the load
leads as short as possible and twist them together. As the sense leads are part of the
power supply’s programming feedback loop, accidental open-connections of sense or
load leads during remote sensing operation have various unwanted effects. Provide
secure and permanent connections.
N o t e During remote sensing setup, it is strongly recommended to power off (by presssing
power ON/OFF button) the power supply to avoid undesirable damage to the load or
the power supply.
CV Regulation
The voltage load regulation specification in chapter 8 applies at the output terminals
of the power supply. When remote sensing, add 5 mV to this specification for each 1
V drop between the positive sensing point and (+) output terminal due to the change
in load current. Because the sense leads are part of the power supply’s feedback path,
keep the resistance of the sense leads at or below 0.5
Ω
per lead to maintain the above
specified performance.
Output Rating
The rated output voltage and current specifications in chapter 8 apply at the output
terminals of the power supply. With remote sensing, any voltage dropped in the load
leads must be added to the load voltage to calculate maximum output voltage. The
performance specifications are not guaranteed when the maximum output voltage is
exceeded. If the excessive demand on the power supply forces the power supply to
lose regulation, the
Unreg
annunciator will turn on to indicate that the output is
unregulated.
Output Noise
Any noise picked up on the sense leads also appears at the output of the power supply
and may adversely affect the voltage load regulation. Twist the sense leads to minimize
external noise pickup and run them parallel and close to the load leads. In noisy
environments it may be necessary to shield the sense leads. Ground the shield at the
power supply end only.
Do not use the shield as one of the sense conductors .