BEL SRSB

ISOLATED DC/DC CONVERTERS
36 Vdc - 75 Vdc Input,
12 Vdc/5 A Output
Bel Power Inc., a subsidiary of Bel Fuse Inc.
Apr. 29, 2011
SRSB-50T12C
RoHS Compliant
PRELIMINARY
Rev.A
Features

Isolated

Output Over Voltage Shutdown

High Efficiency

Over Temperature Protection

Fixed Frequency (600 kHz)

SCP/OCP

High Power Density

Basic Insulation

Input Under Voltage Lockout

Remote On/Off

Low Cost


Class 2, Category 2, Isolated DC/DC Converter (refer to IPC-9592)

UL60950-1 Recognized (UL/cUL) (Pending)
Applications

Networking

Computers and peripherals

Telecommunications
Description
The SRSB-50T12C is an isolated dc/dc converter that operates from a nominal 48 Vdc source. The unit will
provide up to 60 W of output power from a nominal 48 Vdc input. The unit is designed to be highly efficient and
low cost. Features include remote on/off, over current protection and under-voltage lockout. The converter is
provided in an industry standard sixteenth brick package.
Part Selection
Output Voltage
Input Voltage
12 Vdc
36 Vdc - 75 Vdc
Max. Output
Current
5A
Max. Output
Power
60 W
Typical
Efficiency
89%
Model Number
Active Low
SRSB-50T12C
Notes: Add “G” suffix at the end of the model number to indicate Tray Packaging.
Part Number Explanation
S R SB – 50 T 12 C
1 2
3
4
5 6
7
1---Surface Mount
2---RoHS 6, change “R” to “7” means RoHS 5
3---Series name, 1/16 brick
4---Series code
5---Input range (36-75V)
6---Output voltage (12V)
7---Option, “x” of the model part number to be 0-9, A-Z, which will represent the special request of
customer.
Bel Fuse Inc. 206 Van Vorst Street, Jersey City, NJ 07302  Tel 201-432-0463  Fax 201-432-9542  www.belfuse.com
1
ISOLATED DC/DC CONVERTERS
36 Vdc - 75 Vdc Input,
12 Vdc/5 A Output
Bel Power Inc., a subsidiary of Bel Fuse Inc.
Apr. 29, 2011
Absolute Maximum Ratings
Min
Typ
Max
Unit
Continuous Input Voltage
-0.3
-
80
V
Input Transient Voltage
-0.3
-
100
V
Remote On/Off
-0.3
-
18
V
Parameter
I/O Isolation Voltage
Notes
100mS maximum
-
-
1500
V
Ambient Temperature
-40
-
85
C
Storage Temperature
-55
-
125
C
Note: Ratings used beyond the maximum ratings may cause a reliability degradation of the converter or may
permanently damage the device.
Input Specifications
Parameter
Operating Input Voltage
Min
36
Input Current (full load)
-
-
2.4
A
Input Current (no load)
-
70
120
mA
Remote Off Input Current
-
1
3
mA
Input Reflected Ripple Current
(rms)
-
3
7
mA
Input Reflected Ripple Current
(pk-pk)
-
20
50
mA
I t Inrush Current Transient
-
0.01
0.02
As
Turn-on Voltage Threshold
31
32
35
V
Turn-off Voltage Threshold
30
31
34
V
2
Typ
48
Max
75
Unit
V
Notes
With simulated source impedance of
15uH, 5Hz to 20MHz; use a
100uF/100V electrolytic capacitor with
ESR=1 ohm max, at [email protected]°C.
2
Note: All specifications are typical at 25 C unless otherwise stated.
Output Specifications
Parameter
Min
Typ
Max
Unit
11.75
12.00
12.25
V
Load Regulation
-
±9
±18
mV
Line Regulation
-
±10
±25
mV
Regulation Over Temperature
(-40deg.C-85deg.C)
-
±20
±35
mV
Total Regulation
-
±39
±78
mV
Output Ripple and Noise (pk-pk)
-
90
180
mV
Output Ripple and Noise (rms)
-
30
55
mV
Output Current Range
0
-
5
A
5.2
6.5
8.5
A
Output Voltage Set Point
Output DC Current Limit
Notes
Vin=48 V, Io=50%Load
0-20MHz BW, with a 1µF ceramic
capacitor and the minimum
external Tantalum cap at output.
Bel Fuse Inc. 206 Van Vorst Street, Jersey City, NJ 07302  Tel 201-432-0463  Fax 201-432-9542  www.belfuse.com
2
ISOLATED DC/DC CONVERTERS
36 Vdc - 75 Vdc Input,
12 Vdc/5 A Output
Bel Power Inc., a subsidiary of Bel Fuse Inc.
Apr. 29, 2011
Output Specifications (continued)
Parameter
Min
Typ
Max
Unit
2
Short Circuit Surge Transient
-
0.5
1
As
Turn on Time
-
35
70
mS
Overshoot at Turn on
-
0
5
%
22
-
470
uF
Output Capacitance
Transient Response
△V
Overshoot
25%~50%
of Max Load Settling Time
△V
50%~25%
of Max Load
Overshoot
Vo=
12 V
Settling Time
-
400
650
mV
-
150
300
uS
-
400
650
mV
-
150
300
uS
Notes
di/dt=0.1A/us, Vin=48Vdc, Ta=25°C,
with a 1µF ceramic capacitor and
the minimum external Tantalum cap
at output.
Note: All specifications are typical at nominal input, full load at 25°C unless otherwise stated.
General Specifications
Parameter
Efficiency
Switching Frequency
Min
Typ
Max
Unit
86
89
-
%
-
600
-
kHz
Notes
Vin=48 V, full load.
Over Temperature Protection
-
125
-
℃
The OTP threshold is set at 125°C
in non-latch mode, and the module
will restart automatically when
temperature falls down to 115°C.
Over Voltage Protection (Static)
-
130
160
%
This voltage is achieved by trimming
up output slowly.
Weight
-
TBD
-
g
Dimensions
Inches (L × W × H)
Millimeters (L × W × H)
1.300 x 0.900 x 0.364
33.02 x 22.86 x 9.24
-
-
-
1500
V
10M
-
-
Ohm
-
3900
-
pF
Isolation characteristics
Input to Output
Isolation Resistance
Isolation Capacitance
Note: All specifications are typical at 25 C unless otherwise stated.
Bel Fuse Inc. 206 Van Vorst Street, Jersey City, NJ 07302  Tel 201-432-0463  Fax 201-432-9542  www.belfuse.com
3
ISOLATED DC/DC CONVERTERS
36 Vdc - 75 Vdc Input,
12 Vdc/5 A Output
Bel Power Inc., a subsidiary of Bel Fuse Inc.
Apr. 29, 2011
Efficiency Data
90%
85%
EFFICIENCY
80%
75%
36V
70%
48V
75V
65%
60%
55%
50%
0.5A
1.25A
2.5A
3.75A
5A
OUTPUT CURRENT (A)
Thermal Derating Curve
Maximum junction temperature of semiconductors derated to 120 degree C.
Derating curve under 48V input range
Bel Fuse Inc. 206 Van Vorst Street, Jersey City, NJ 07302  Tel 201-432-0463  Fax 201-432-9542  www.belfuse.com
4
ISOLATED DC/DC CONVERTERS
36 Vdc - 75 Vdc Input,
12 Vdc/5 A Output
Bel Power Inc., a subsidiary of Bel Fuse Inc.
Apr. 29, 2011
Transient Response Waveforms
50%-25% Load Transients at Vin=48 V
25%-50% Load Transients at Vin=48 V
Note: Transient response at Vout=12V, di/dt=0.1A/us, External 22uF Tantalum Cap and 1uF Ceramic Cap, and
Ta=25 deg C.
Ripple and Noise Waveform
48 Vdc input, 12 Vdc/5 A output
Note: Ripple and noise at full load, and with a 1uF ceramic cap and a 22 uF Tantalum cap at output, Ta=25 deg
C.
Bel Fuse Inc. 206 Van Vorst Street, Jersey City, NJ 07302  Tel 201-432-0463  Fax 201-432-9542  www.belfuse.com
5
ISOLATED DC/DC CONVERTERS
36 Vdc - 75 Vdc Input,
12 Vdc/5 A Output
Bel Power Inc., a subsidiary of Bel Fuse Inc.
Apr. 29, 2011
Remote On/Off
Parameter
Signal Low (Unit On)
Signal High (Unit Off)
Active Low
Current Sink
Min
-0.3
Typ
-
Max
0.8
Unit
V
2.95
-
18
V
0
-
1
mA
Notes
The remote on/off pin open, Unit off.
Recommended remote on/off circuit for active low
Vin+
Vin+
On/off
On/off
Vin-
Vin-
Control with open collector/drain circuit
Control with photocoupler circuit
Vin+
Vin+
On/off
On/off
Vin-
Vin-
Vcc
Control with logic circuit
Permanently on
Bel Fuse Inc. 206 Van Vorst Street, Jersey City, NJ 07302  Tel 201-432-0463  Fax 201-432-9542  www.belfuse.com
6
ISOLATED DC/DC CONVERTERS
36 Vdc - 75 Vdc Input,
Apr. 29, 2011
12 Vdc/5 A Output
Bel Power Inc., a subsidiary of Bel Fuse Inc.
Mechanical Outline
Pin Connections
pin#
1
2
3
4
5
function
Vin (+)
On/Off
Vin (-)
Vout (-)
Vout (+)
Note: This module is recommended and compatible with Pb-Free Reflow Soldering and must be soldered
using a reflow profile with a peak temperature of no more than 260ºC for less than 5 seconds.
Note:
1) All Pins: Material - Copper Alloy;
Finish – 3 micro inches minimum Gold over 50 micro inches minimum Nickel plate.
2) Undimensioned components are shown for visual reference only.
3) All dimensions in inches (mm); Tolerances: x.xx +/-0.02 in. (x.x +/-0.5mm) x.xxx +/-0.010 in. (x.xx +/-0.25mm).
Bel Fuse Inc. 206 Van Vorst Street, Jersey City, NJ 07302  Tel 201-432-0463  Fax 201-432-9542  www.belfuse.com
7
ISOLATED DC/DC CONVERTERS
36 Vdc - 75 Vdc Input, 12 Vdc/5 A Output
Bel Power Inc., a subsidiary of Bel Fuse Inc.
Apr. 29, 2011
Revision History
Date
Version
2010-04-29
PA
Changes Detail
Approval
First release
JZ Wang
RoHS Compliance
Complies with the European Directive 2002/95/EC, calling for the elimination of lead and
other hazardous substances from electronic products.
2011 Bel Fuse Inc. Specifications subject to change without notice. 042911
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CORPORATE
FAR EAST
EUROPE
Bel Fuse Inc.
206 Van Vorst Street
Jersey City, NJ 07302
Tel 201-432-0463
Fax 201-432-9542
www.belfuse.com
Bel Fuse Ltd.
8F/ 8 Luk Hop Street
San Po Kong
Kowloon, Hong Kong
Tel 852-2328-5515
Fax 852-2352-3706
www.belfuse.com
Bel Fuse Europe Ltd.
Preston Technology Management Centre
Marsh Lane, Suite G7, Preston
Lancashire, PR1 8UD, U.K.
Tel 44-1772-556601
Fax 44-1772-888366
www.belfuse.com