FHS Series – 500W Full-Brick DC/DC Converter
48V Input
12V, 24V, 28V Output
Preliminary Data Sheet
Features
•
•
•
•
•
•
•
•
•
•
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•
Low profile – 12.7 mm height
Input/output isolation: 1500VDC, Basic
insulation, 2250VDC withstand capability
High efficiency - up to 93% at full load
Start-up into high capacitive load
Low conducted and radiated EMI
Output overcurrent protection
Output overvoltage protection
Overtemperature protection
Remote sense
Remote on/off (primary referenced), positive
or negative logic option
Output voltage trim adjust, positive or
negative option
UL 1950 Recognition, CSA 22.2 No. 950-95
certification, TUV IEC950
Applications
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•
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Distributed power architectures
Telecommunications equipment
LAN/WAN applications
Data processing applications
Description
The FHS Series power modules are DC/DC converters that operate over an input voltage range of 36 to 75VDC and
provide a regulated DC output voltage at up to 42 amps of output current. The output is fully isolated from the input,
which allows a positive or negative output configuration.
The open-frame module is constructed with a two-board approach. The power devices are connected to an
Insulated Metal Substrate (IMS) base plate, which provides very low thermal impedance. A separate PCB is
populated with the control circuitry and is physically isolated from the hotter IMS board. This approach allows for
lower component temperatures, hence increased reliability. The standard feature set includes remote on/off, remote
output voltage sensing, positive logic output trim (optional negative logic output trim available), input under and
overvoltage lockout and overtemperature shutdown with hysteresis.
A microcontroller has been employed within the supervisory circuitry offering increased flexibility in the product’s
feature set. (Remote on/off logic can be selected at the time of manufacture to be either positive or negative with a
simple program change. Similarly, overcurrent protection and output overvoltage protection functions can be
changed from the normal non-latching mode to latching mode with a simple program change. Specific changes
should be discussed with the factory.)
Selection Chart
Model
Input
voltage
(VDC)
36-75
36-75
36-75
Input
current,
Max, (ADC)
16
16
16
Output
voltage
(VDC)
12
24
28
Output rated
current
I
rated,
(ADC)
42
21
18
Output
Ripple/Noise
(mV p-p)
100
150
150
Typical
Efficiency
@ I
rated,
(%)
92.5
92.5
93
FHS42ZH
FHS21ZK
FHS18Z28
This product is intended for integration into end-use equipment. All the required procedures for CE marking of end-use
equipment should be followed
.
REV. SEP 20, 2002
Page 1 of 11
FHS Series – 500W Full-Brick DC/DC Converter
48V Input
12V, 24V, 28V Output
Preliminary Data Sheet
Absolute Maximum Ratings
Stresses in excess of the absolute maximum ratings may cause performance degradation, adversely effect long-
term reliability and cause permanent damage to the converter.
Parameter
Input voltage
Operating Temperature
Storage Temperature
ON/OFF Control Voltage
Conditions/Description
Continuous
Transient, 100ms (
non operating
)
Base Plate Temperature
Referenced to -Vin
Min
Max
75
100
115
125
7
Units
VDC
VDC
°C
°C
VDC
-40
-40
Environmental and Mechanical Specifications
All specifications apply over specified input voltage, output load and temperature range, unless otherwise noted.
Parameter
Shock
Sinusoidal Vibration
Weight
Water Washing
MTBF
Conditions/Description
Halfsine wave, 3 axes
GR-63-Core, Section 5.4.2
Standard process
Per Bellcore TR-NWT-000332
Min
50
1
Nom
Max
Units
g
g
Oz/g
kHrs
1.2/35
Yes
1,000
Isolation Specifications
All specifications apply over specified input voltage, output load and temperature range, unless otherwise noted.
Parameter
Insulation Safety Rating
Isolation Voltage
Isolation Voltage
Isolation Resistance
Isolation Capacitance
Conditions/Description
Input to output, input to base plate
Output to base plate
Min
2250
2250
10
1000
Nom
Basic
Max
Units
VDC
VDC
MOhm
pF
Input Specifications
All specifications apply over specified input voltage, output load and temperature range, unless otherwise noted.
Parameter
Input Voltage
Turn-On Input Voltage
Turn-Off Input Voltage
Input over voltage protection
Turn-On Time
Input Reflected Ripple Current
Inrush Transient
Conditions/Description
Continuous
Ramping Up
Ramping Down
Ramping up
To Output Regulation Band
100% Resistive Load
Full Load, 12uH source
inductance
Vin=Vin.max
Min
36
Nom
48
34
33
Max
75
Units
VDC
VDC
VDC
VDC
ms
mA p-p
A
2
s
76
84
5
60
0.1
REV. SEP 20, 2002
Page 2 of 11
FHS Series – 500W Full-Brick DC/DC Converter
48V Input
12V, 24V, 28V Output
Preliminary Data Sheet
Output Specifications
All specifications apply over specified input voltage, output load and temperature range, unless otherwise noted.
Parameter
Output Voltage Setpoint Accuracy
12V
24V
28V
Output Current
Line Regulation
Load Regulation
Total output voltage regulation
Remote Sense Headroom
Dynamic Regulation
Peak Deviation
12V
24V
28V
Settling Time
12V
24V
28V
Admissible Load Capacitance
Output Current Limit Threshold**
Switching Frequency
Overvoltage Protection,
Non Latching
Trim Range
Conditions/Description
Vin=Vin.nom, Full Load
Min
-2
-2
-2
10
Nom
Max
2
2
2
100
0.2
0.5
3
5%
50-75% load step change
150
250
250
to 1% error band
500
250
250
I
rated, resistive load
, Nom Vin
Vout≤0.97Vout.nom
Over all input voltage and
load conditions
I
rated
, Vin=Vnom
110
400
120
90
140
110
500
750
750
100
150
µs
µs
µs
µF/A
%I
rated
kHz
%Vout
%Vout
500
750
750
mV
mV
mV
Units
%Vout
%Vout
%Vout
%I
rated
%Vout
%Vout
%Vout
%Vout
See selection chart for I
rated
Vin.min to Vin.max, I
rated
Vin=Vin.nom, 10% to
100%I
rated
Over all input voltage, load,
and temperature conditions
-3
** Overcurrent protection is non-latching with auto recovery.
REV. SEP 20, 2002
Page 3 of 11
FHS Series – 500W Full-Brick DC/DC Converter
48V Input
12V, 24V, 28V Output
Preliminary Data Sheet
Feature Specifications
All specifications apply over specified input voltage, output load and temperature range, unless otherwise noted.
Parameter
Shutdown (ON/OFF)
Negative Logic
Converter ON
Source Current
Converter OFF
Open Circuit Voltage
Positive Logic
Converter ON
Open Circuit Voltage
Converter OFF
Source Current
Overtemperature
Protection
Conditions/Description
On/Off signal is low – converter is ON
-0.5
ON/OFF pin is connected to -Vin
2.5
ON/OFF pin is floating
On/Off signal is low–converter is OFF
2.5
ON/OFF pin is floating
-0.5
ON/OFF pin is connected to -Vin
Baseplate temperature
120
0.8
1
7
5
7
5
0.8
1
130
VDC
mADC
VDC
VDC
VDC
VDC
VDC
mADC
°C
Min
Nom
Max
Units
REV. SEP 20, 2002
Page 4 of 11
FHS Series – 500W Full-Brick DC/DC Converter
48V Input
12V, 24V, 28V Output
Preliminary Data Sheet
Characteristic Curves
18
Tamb=25C
100.00
98.00
96.00
92.00
90.00
Efficiency (%)
88.00
86.00
84.00
82.00
80.00
78.00
76.00
74.00
72.00
70.00
10%
20%
30%
FHS42ZH Efficiency vs. Load
16
14
12
10
8
6
36.00
48.00
75.00
4
2
0
20
30
40
50
60
70
80
Input Current (A)
94.00
Input Voltage (V)
40%
50%
60%
70%
80%
90%
100%
LOAD (%)
Fig. 4 FSH42ZH Input Characteristic
18
16
Fig. 1 FHS42ZH Efficiency vs. Output Load
Tamb=25C
Efficiency vs. Load
100.00
98.00
96.00
94.00
92.00
90.00
88.00
86.00
84.00
82.00
80.00
78.00
76.00
74.00
72.00
70.00
10%
20%
30%
40%
50%
60%
LOAD (%)
14
12
Input Current (A)
36.03
48.04
75.05
10
8
6
4
2
0
Efficiency (%)
0
10
20
30
40
Input Voltage (V)
50
60
70
80
70%
80%
90%
100%
Fig. 5 FHS21ZK Input Characteristic
18
16
Fig. 2 FHS21ZK Efficiency vs. Output Load
Tamb=25C
FHS18Z28 Efficiency vs. Load
14
12
100.00
98.00
96.00
94.00
92.00
90.00
88.00
86.00
84.00
82.00
80.00
78.00
76.00
74.00
72.00
70.00
10%
20%
30%
40%
50%
Input Current (A)
10
8
6
Efficiency (%)
36.00
48.00
75.00
4
2
0
0
10
20
30
40
Input Voltage (V)
50
60
70
80
60%
70%
80%
90%
100%
LOAD (%)
Fig. 3 FHS18Z28 Efficiency vs. Output Load
REV. SEP 20, 2002
Fig. 6 FHS18Z28 Input Characteristic
Page 5 of 11