
PSA Series Extended Data Sheet
Positive Switching Regulator (Rugged)
REV. SEP 23, 2003
Page 7 of 13
R Control for Output Voltage Adjustment
Note: With open R input, Uo
≈ U
o nom. R excludes option P.
The output voltage Uo can either be adjusted with an ex-
ternal voltage (Uext) or with an external resistor (R1 or R2).
The adjustment range is 0…108% of Uo nom. The mini-
mum differential voltage
DUio min between input and output
(see: Electrical Input Data) should be maintained. Under-
voltage lock-out = Minimum input voltage.
Fig. 9
Voltage adjustment with Uext between R and Go–
a) Uo = 0...108% Uo nom, using Uext between R and Go–:
Uo
Uext
≈ 2.5 V –––––
Uo
≈ U
o nom –––––
Uo nom
2.5 V
Fig. 10
Voltage adjustment with external resistor R1 or R2
b) Uo = 0...100% Uo nom, using R1 between R and Go–:
4000
U
o
Uo nom R1
R1
≈ –––––––––––
Uo
≈ –––––––––––
Uo nom – Uo
R1 + 4000
c) Uo = Uo nom...Uo max, using R2 between R and Vo+:
Uo max = Uo nom + 8%
4000
U
o (Uo nom – 2.5 V)
R2
≈ ––––––––––––––––––––––––
2.5 V (Uo – Uo nom)
Uo nom 2.5 V R2
Uo ≈ ––––––––––––––––––––––––––––––––
2.5 V (R2 + 4000 ) – Uo nom 4000
Vo+
R
+
4000
G
Uref
Uext
–
+
Go –
06035
Caution: To prevent damage Uext should not exceed
20 V, nor be negative and R2 should never
be less than 47 k
.
Vo+
R
–
+
G
4000
Uref
R1
R2
Go –
06036
LED Output Voltage Indicator
A yellow output indicator LED shines when the output volt-
age is higher than approx. 3 V.