Technical data

DC Power Supply Operation 3
Remote Sensing
U3606A User’s and Service Guide 105
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 instrument 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 instrument
programming feedback loop, accidental open- connections of sense or load
leads during remote sensing operation have various unwanted effects.
Provide secure and permanent connections.
CV regulation
The voltage load regulation specification in Chapter 8, “Characteristics and
Specifications,” starting on page 239 applies at the output terminals of the
U3606A. When remote sensing, add 5 mV to this specification for each 1 V
drop between the positive sensing point (S+) and output terminals (+) due
to the change in load current. Because the sense leads are part of the
U3606A 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,
“Characteristics and Specifications,” starting on page 239 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.
Output noise
Any noise picked up on the sense leads also appears at the output of the
U3606A 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 U3606A end only. Do not
use the shield as one of the sense conductors.