PSB Series Extended Data Sheet
Positive Switching Regulators (Rugged)
REV. OCT 17, 2003
Page 2 of 13
Part Number Descriptions
PSB 12 3 -7 L i R P C
Positive switching regulator in case B02 ................... PSB
Nominal output voltage in volt (5A for 5.1 V) ....... 5A, ... 48
Nominal output current in ampere ............................. 4, 5
Operational ambient temperature range
T
A
–25 to 71°C ......................................................... -7
–40 to 71°C (option) ........................................... -9
Input filter (option) ............................................................ L
Inhibit input ....................................................................... i
Control input for output voltage adjustment 1 ................. R
Potentiometer 1 (option) ................................................... P
Thyristor crowbar (option) .............................................. C
1 Feature R excludes option P and vice versa.
Example:
PSB 123-7LiPC = A positive switching regulator with a 12 V, 3 (4) A output, ambient temperature range of
–25 to 71°C, input filter, inhibit input, potentiometer and thyristor crowbar.
Control circuit
Option P
Go–
Vo+
Gi–
Vi+
Input
Filter
Option
L
G
R
i
G
Io
Vo
I i
Vi
Option C
03011
Fig. 1
Block diagram
Functional Description
The switching regulators are designed using the buck con-
verter topology. See also:
Technical Information: Topolo-
gies. The input is not electrically isolated from the output.
During the on period of the switching transistor, current is
transferred to the output and energy is stored in the output
choke. During the off period, this energy forces the current
to continue flowing through the output choke to the load
and back through the freewheeling diode. Regulation is
accomplished by varying the on/off duty ratio of the power
switch.
These regulators are ideal for a wide range of applica-
tions, where input to output isolation is not necessary, or
where already provided by an external front end (e.g. a
transformer with rectifier). To optimise customer’s needs,
additional options and accessories are available.