PSS, PSK Extended Data Sheet
Positive Switching Regulators (Benign)
Input voltage up to 60 VDC
Single output of 5.1 to 24 VDC
No input to output isolation
•
High efficiency up to 94%
•
Wide input voltage range
• Low input-to-output differential voltage
•
Very good dynamic properties
•
Input undervoltage lock-out
•
Active current sharing for parallel operation
111
4.4"
3U
60
2.4"
12 TE
168
6.6"
• Output voltage adjustment, inhibit and sense lines
• Fast dynamic response
•
Continuous no-load and short-circuit proof
•
No derating
Safety according to IEC/EN 60950, UL 1950
Summary
The PSS/PSK series of positive switching regulators is de-
signed as power supply modules for electronic systems.
Their major advantages include a high level of efficiency
that remains virtually constant over the entire input range,
high reliability, low ripple and excellent dynamic response.
Modules with input voltages up to 60 V are specially desig-
ned for secondary switched and battery-driven applica-
tions. The standard case design with heat sink allows op-
eration at nominal load up to 50°C without additional cool-
ing, suitable for 19" rack or chassis mounting.
111
4.4"
3U
80
3.2"
16 TE
168
6.6"
Replacing the heat sink by an optional cooling plate B or B1,
allows chassis or wall mounting on top of a metal surface,
acting as heat sink.
Connector type: H15 (according to DIN 41612).
Table of Contents
Page
Page
Electromagnetic Compatibility (EMC) .............................. 8
Immunity to Environmental Conditions ............................ 8
Mechanical Data .............................................................. 9
Safety and Installation Instructions ................................ 11
Description of Options ................................................... 13
Accessories ................................................................... 14
EC-Declaration of conformity ......................................... 15
Summary .......................................................................... 1
Type Survey and Key Data .............................................. 2
Type Key and Product Marking ........................................ 2
Functional Description ..................................................... 3
Electrical Input Data ......................................................... 3
Electrical Output Data ...................................................... 4
Auxiliary Functions ........................................................... 6
REV. FEB 15, 2004
Page 1 of 15
PSS, PSK Extended Data Sheet
Positive Switching Regulators (Benign)
Model Selection and Key Data
Table 1: Type survey
Output
voltage
V
o nom
[V]
5.1
5.1
12
12
15
15
24
24
1
Output
current
I
o nom
[A]
14
18
14
18
14
18
14
18
Input
voltage range
V
i
[V]
1
8...40
8...40
15...40
15...40
19...40
19...40
29...60
29...60
Input
voltage
V
i nom
[V]
20
20
30
30
30
30
40
40
Efficiency
at
V
i nom
,
I
o nom
h
min
[%]
83
82
90
90
90
90
94
94
Type
designation
PSS 5A14-2
PSK 5A18-2
PSS 1214-2
PSK 1218-2
PSS 1214-2
PSK 1218-2
PSS 2414-2
PSK 2418-2
Options
B
B1
See also:
Electrical Input Data:
D
V
io min
.
Part Number Description and Product Marking
Type Key
PSK 12 18 -2 B
Positive switching regulator in case S01, K01 - PSS, PSK
Nominal output voltage in volt (5A for 5.1 V) ......... 5A,...24
Nominal output current in ampere .......................... 14, 18
Operational ambient temperature range –10 to 50°C ... -2
Options:
Example:
Cooling plate large / small .................. B / B1
PSK 1218-2B = A positive switching regulator with a 12 V, 18 A output, ambient temperature range of
–10 to 50°C and large cooling plate option B.
Note:
All units features the following auxiliary functions which are not shown in the type designation: Input filter, inhibit, R
control, sense lines and current sharing.
Produkt Marking
Basic type designation, applicable safety approvals and recognition marks, warnings, pin allocation, Power-One patents
and company logo.
Specific type designation, input voltage range, nominal output voltage and current, protection degree, batch no., serial no.
and data code including production site, modification status and date of production.
REV. FEB 15, 2004
Page 2 of 15
PSS, PSK Extended Data Sheet
Positive Switching Regulators (Benign)
Functional Description
The switching regulators are designed using the buck con-
verter topology. 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 chocke
to the load and back through the freewheeling diode.
Regulation is accomplished by varying on/off duty cycle.
These regulators are ideal for a wide range of
applications, 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.
03020
4
I
o
Vo+
I
i
Vi+
30
32
6
20
S+
CS
i
R
S–
Input Filter
22
V
i
Control
circuit
14
16
18
V
o
26
Gi–
28
24
8
10
Go–
Fig. 1
Block diagram
Electrical Input Data
General Conditions:
T
A
= 25°C, unless
T
C
is specified
Table 2: Input data
Input
Characteristics
Conditions
PSS 5A14
PSK 5A18
PSS 1214
PSK 1218
PSS 1214
1
PSK 1218
1
min typ max
19
40
4
7.3
50
A
50
A
12
50
A
mA
dB (µV)
PSS 2414
PSK 2418
min typ max
29
60
5
Unit
VDC
min typ max min typ max
8
40
2.9
7.3
7.3
50
A
15
40
3
V
i
Operating input voltage
D
V
io min
Min. diff. voltage
V
i
–
V
o
I
o
= 0
–
I
o nom
T
C min
–
T
C max
V
i o
I
i 0
u
i RFI
1
Undervoltage lock-out
No load input current
I
o
= 0,
V
i min
–
V
i max
Input RFI level, EN 55011/22
V
i nom
,
I
o nom
0.15...30 MHz
Output set to 15 V at R control input, see:
Auxiliary Functions.
Input Filter and Fuse
An input filter and a fuse are incorporated in all modules as
standard. The filter reduces emitted electrical noise and
prevents oscillations caused by the negative input imped-
ance characteristic of a switched mode regulator. The input
fuse protects against severe defects.
The maximum permissible additionally superimposed rip-
ple
v
i
of the input voltage (rectifier mode) at a specified in-
put frequency
f
i
has the following values:
Inrush Current
The inrush current can reach very high values depending
on the source and input line conditions. The inrush current
into a switching regulator is limited by parasitic components
of the voltage source and power supply input only. This in-
put presents a very low impedance to such currents and
when driven from a low impedance source, e.g. a battery,
the inrush current can peak at several orders of magnitude
above the continuous DC input current. To protect series el-
ements such as switches or circuit brakers and rectifiers the
use of additional external current limitation device is recom-
mended.
v
i max
= 10 V
pp
at 100 Hz, or V
pp
= 1000 Hz/f
i
• 1 V
REV. FEB 15, 2004
Page 3 of 15
PSS, PSK Extended Data Sheet
Positive Switching Regulators (Benign)
Electrical Output Data
General Conditions:
–
T
A
= 25°C, unless
T
C
is specified
– With R control output voltage
V
o
=
V
o nom
at
I
o nom
– Sense lines connected at female connector
Table 3a: Output data PSS
Output
Characteristics
Conditions
PSS 5A14
min typ max
5.05
0
14.0
PSS 1214
min typ max
PSS 1214
1
min typ max
PSS 2414
min typ max
24.70
14.0
17.5
300
310
480
240
700
60
±3
±0.02
±5
µs
mV/K
mV
mV
pp
Unit
V
A
V
o
I
o
I
oL
v
o
Output voltage
Output current
2
V
i nom
,
I
o nom
V
i min
–
V
i max
T
C min
–
T
C max
5.15 11.60
14.0
17.5
55
60
100
100
150
40
±1
±0.02
360
60
0
14.0
12.40 14.50
14.0
17.5
150
160
240
120
450
60
±2
±0.02
0
14.0
15.50 23.30
14.0
17.5
200
210
300
150
0
14.0
Output current limitation
response
Output
voltage
noise
Switching freq.
V
i nom
,
I
o nom
IEC/EN 61204
3
Total
BW = 20 MHz
D
V
o U
D
V
o l
Static line regulation
Static load regulation
Dynamic
load
regulation
V
i min
–
V
i max
,
I
o nom
V
i nom
,
I
o
= 0 –
I
o nom
v
o d
t
d
a
Uo
Voltage deviat.
V
i nom
I
↔
1
/
3
I
o nom
Recovery time
o nom
IEC/EN 61204
Temperature coefficient
D
V
o
/DT
C
(T
C min
–
T
C max
)
V
i min
–
V
i max
I
o
= 0 –
I
o nom
±0.02 %/K
Table 3b: Output data PSK
Output
Characteristics
Conditions
PSK 5A18
min typ max
5.05
0
18.0
PSK 1218
min typ max
PSK 1218
1
min typ max
PSK 2418
min typ max
24.70
18.0
22.5
300
310
480
240
700
60
±3
±0.02
±5
µs
mV/K
mV
mV
pp
Unit
V
A
V
o
I
o
I
oL
v
o
Output voltage
Output current
2
V
i nom
,
I
o nom
V
i min
–
V
i max
T
C min
–
T
C max
5.15 11.60
18.0
22.5
55
60
100
100
150
40
±1
±0.02
360
60
0
18.0
12.40 14.50
18.0
22.5
150
160
240
120
450
60
±2
±0.02
0
18.0
15.50 23.30
18.0
22.5
200
210
300
150
0
18.0
Output current limitation
response
Output
voltage
noise
Switching freq.
V
i nom
,
I
o nom
IEC/EN 61204
3
Total
BW = 20 MHz
D
V
o U
D
V
o l
Static line regulation
Static load regulation
Dynamic
load
regulation
V
i min
–
V
i max
,
I
o nom
V
i nom
,
I
o
= 0 –
I
o nom
v
o d
t
d
a
Uo
Voltage deviat.
V
i nom
I
↔
1
/
3
I
o nom
Recovery time
o nom
IEC/EN 61204
Temperature coefficient
D
V
o
/DT
C
(T
C min
–
T
C max
)
V
i min
–
V
i max
I
o
= 0 –
I
o nom
±0.02 %/K
1
2
Output set to 15 V at R control input, see:
Auxiliary Functions.
See also:
Thermal Considerations.
REV. FEB 15, 2004
Page 4 of 15
PSS, PSK Extended Data Sheet
Positive Switching Regulators (Benign)
V
o
Vod
05010
Overtemperature Protection
The unit is self-protecting by an internal temperature moni-
tor, which inhibits the output above
T
C max
. The output is au-
tomatically enabled again after temperature has dropped
below
T
C max
.
Output Protection
A voltage suppressor diode which in worst case conditions
fails into a short circuit, protects the output against an inter-
nally generated overvoltage. Such an overvoltage could oc-
cur due to a failure of either the control circuit or the switch-
ing transistor. The output protection is not designed to with-
stand externally applied overvoltages. The user should en-
sure that systems with Power-One power supplies, in the
event of a failure, do not result in an unsafe condition (fail-
safe).
Parallel and Series Connection
Outputs of equal nominal voltage can be parallel-con-
nected. Use the current sharing feature (CS) for even distri-
bution of the output current. See also:
Auxiliary Functions.
Outputs can be series-connected with any other module. In
series-connection the maximum output current is limited by
the lowest current limitation. Electrically isolated source
voltages are needed for each module!
Short Circuit Behaviour
A constant current limitation circuit holds the output current
almost constant whenever an overload or a short circuit is
applied to the regulator's output. It acts self-protecting and
recovers – in contrary to the fold back method – automati-
cally after removal of the overload or short circuit condition.
V
o
/V
o nom
1.2
1.0
0.8
D
V
o I
D
V
o I
t
d
I
o
/I
o nom
1
Vod
t
d
t
0
≥10
µs
≥10
µs
t
Fig. 2
Dynamic load regulation.
Thermal Considerations
When a switching regulator is located in free, quasi-station-
ary air (convection cooling) at a temperature
T
A
= 50°C and
is operated at its nominal output current
I
o nom
, the case
temperature
T
C
will be about 80°C after the warm-up
phase, measured at the
Measuring point of case tempera-
ture T
C
(see:
Mechanical Data).
Under practical operating conditions, the ambient tem-
perature
T
A
may exceed 50°C, provided additional meas-
ures (heat sink, fan, etc.) are taken to ensure that the case
temperature
T
C
does not exceed its maximum value of
80°C.
Example: Sufficient forced cooling allows
T
A max
= 65°C. A
simple check of the case temperature
T
C
(T
C
≤80°C)
at full
load ensures correct operation of the system.
I
o
/I
o nom
Forced cooling
1.0
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
05032
I
o nom
05038
Convection cooling
0.6
I
o L
T
C max
0.4
0.2
0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
I
o
/I
o nom
T
A min
40
50
60
70
80
T
A
[ C]
Fig. 4
Overload, short-circuit behaviour V
o
versus I
o
.
Fig. 3
Output current derating versus temperature.
REV. FEB 15, 2004
Page 5 of 15