Bel Fuse Inc.
206 Van Vorst Street, Jersey City, NJ 07302
Tel 201-432-0463 Fax 201-432-9542 www.belfuse.com
ISOLATED DC/DC CONVERTERS
48V Input 3.3V/15A, 5V/12A, 12V/5A Outputs, 1/16 Brick Converter
Isolated
Input Under Voltage Lockout
Fixed
Frequency
Output Over Voltage Shutdown
High
Efficiency
OCP/SCP
High Power Density
Over Temperature Protection
Low
Cost
Remote
On/Off
Active Low/High Option
Description
The S7SB-50T series are isolated DC/DC converters that operate from a nominal 48V source. These units will
provide up to 60W of output power from a nominal 48V input. These units are designed to be highly efficient and
low cost. Features include remote on/off, over current protection and under voltage lockout. These converters
are provided in an industry standard sixteenth brick package.
Part Selection
Output
Voltage
Input
Voltage
Max. Output
Current
Max. Output
Power
Typical
Efficiency
Model Number
Active Low
Model Number
Active High
3.3V
36V - 75V
15A
50W
91%
S7SB-50T03L
S7SB-50T033
5.0V
36V - 75V
12A
60W
92%
S7SB-50T05L
S7SB-50T050
12V
36V - 75V
5A
60W
92%
S7SB-50T12L
S7SB-50T120
Note:
Add "G" suffix at the end of the model number to indicate Tray Packaging.
Absolute Maximum Ratings
Parameter
Min
Typ
Max
Notes
Input Voltage (continuous)
-0.3V
-
80V
Remote On/Off
-0.3V
-
18V
I/O Isolation Voltage
-
-
1500V
Ambient Temperature
-40
C
-
85
C
Storage Temperature
-55
C
-
125
C
Input Specifications
Parameter
Min
Typ
Max
Notes
Input Voltage
36V
48V
75V
Input Current (full load)
-
-
2A
Vo=3.3V, 5.0V, 12V
Input Current (no load)
-
40mA
200mA
Vo=3.3V, 5.0V, 12V
Remote Off Input Current
-
1mA
3mA
Input Reflected Ripple Current (pk-pk)
-
20mA
50mA
Input Reflected Ripple Current (RMS)
-
3mA
7mA
Tested with simulated source
impedance of 10uH, 5Hz to 20MHz;
use a 100uF/100V electrolytic
capacitor with ESR=1 ohm max at
200KHz at the input.
I
2
t Inrush Current Transient
-
0.01A
2
s 0.02A
2
s
Turn On Voltage Threshold
31V
32V
34V
Turn Off Voltage Threshold
30V
31V
33V
Note:
All specifications are typical at nominal input, full load at 25
C unless otherwise stated.
S7SB-50T
Series
PRELIMINARY
Bel Fuse Inc.
206 Van Vorst Street, Jersey City, NJ 07302
Tel 201-432-0463 Fax 201-432-9542 www.belfuse.com
ISOLATED DC/DC CONVERTERS
48V Input 3.3V/15A, 5V/12A, 12V/5A Outputs, 1/16 Brick Converter
Output Specifications
Parameter
Min
Typ
Max
Notes
Output Voltage Set Point
Vo=3.3V
Vo=5.0V
Vo=12V
3.250V
4.925V
11.820V
3.3V
5.0V
12V
3.350V
5.075V
12.180V
Test conditions:
Vin=48V; Io=50% load
Line Regulation
Vo=3.3V
Vo=5.0V
Vo=12V
-
-
-
4mV
5mV
12mV
9mV
10mV
24mV
Load Regulation
Vo=3.3V
Vo=5.0V
Vo=12V
-
-
-
7mV
10mV
30mV
15mV
20mV
60mV
Regulation Over Temperature
Vo=3.3V
Vo=5.0V
Vo=12V
-
-
-
30mV
45mV
60mV
50mV
75mV
100mV
-40
C to +85C
Output Current
Vo=3.3V
Vo=5.0V
Vo=12V
0A
0A
0A
-
-
-
15A
12A
5A
Current Limit Threshold
Vo=3.3V
Vo=5.0V
Vo=12V
19A
13A
6A
22A
15A
7A
26A
18A
8A
Short Circuit Surge Transient
-
0.5A
2
s 1A
2
s
Ripple and Noise (RMS)
Vo=3.3V
Vo=5.0V
Vo=12V
-
-
-
12mV
25mV
25mV
25mV
50mV
50mV
Ripple and Noise (pk-pk)
Vo=3.3V
Vo=5.0V
Vo=12V
-
-
-
55mV
110mV
100mV
100mV
150mV
130mV
Tested at 0-20MHz BW,
with a 1uF ceramic
capacitor and a 10uF
Tantalum capacitor at the
output.
Turn on Time
-
35mS
50mS
Overshoot at Turn on
-
0%
5%
Output Capacitance
Vo=3.3V
Vo=5.0V
Vo=12V
0uF
0uF
0uF
-
-
-
5600uF
3300uF
1000uF
Transient Response
Overshoot -
130mV
200mV
25% ~ 50%
Max Load
Settling Time
-
80uS
150uS
Overshoot -
130mV
200mV
50% ~ 25%
Max Load
Settling Time
Vo=3.3V
- 80uS
150uS
Overshoot -
200mV
300mV
25% ~ 50%
Max Load
Settling Time
-
120uS
250uS
Overshoot -
200mV
300mV
50% ~ 25%
Max Load
Settling Time
Vo=5.0V
- 120uS
250uS
Overshoot -
300mV
400mV
25% ~ 50%
Max Load
Settling Time
-
150uS
300uS
Overshoot -
300mV
400mV
50% ~ 25%
Max Load
Settling Time
Vo=12V
- 150uS
300uS
Test conditions: di/dt =
0.1A/uS, Vin=48V, with a
1uF ceramic capacitor and a
10uF Tantalum capacitor at
the output.
Note:
All specifications are typical at nominal input, full load 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
ISOLATED DC/DC CONVERTERS
48V Input 3.3V/15A, 5V/12A, 12V/5A Outputs, 1/16 Brick Converter
General Specifications
Parameter
Min
Typ
Max
Notes
Efficiency
Vo=3.3V
Vo=5.0V
Vo=12V
88%
88%
88%
91%
92%
92%
-
-
-
Vin=48V, full load
Switching Frequency
540KHz
600KHz
660KHz
Isolation Capacitance
-
1500pF
-
Output Voltage Trim Range
90%Vo
-
110%Vo
Over Temperature Protection
120
C
-
140
C
Over Voltage Protection
117%Vo
122%Vo
126%Vo
MTBF
TBD
Calculated Per Bell Core TR-332 (I
O
=
Nominal; T
a
= 25
C)
Dimensions
Inches (L W H)
Millimeters (L W H)
1.3 x 0.9 x 0.376
33.0 x 22.9 x 9.5
Weight -
15g
-
Note
: All specifications are typical at 25
C
unless otherwise stated.
Control Specifications
Parameter
Min
Typ
Max
Notes
Remote On/Off
Signal Low (Unit On)
-0.3V
-
0.8V
Signal High (Unit Off)
Active Low
2.4V - 18V
Signal Low (Unit Off)
-0.3V
-
0.8V
Signal High (Unit On)
Active High
2.4V - 18V
The remote on/off pin open, Unit
on.
Current Sink
0mA
-
1mA
Output Trim Equations
Equations for calculating the trim resistor are shown below (Unit: k). The Trim Down resistor should be
connected between the Trim pin and Ground pin. The Trim Up resistor should be connected between the Trim
pin and the Vout. Only one of the resistors should be used for any given application.
Notes:
Vo_req=Desired (trimmed) output voltage [V]
Vo=3.308V for 3.3V output; Vo=5.002 for 5V output; Vo=12.007 for 12V output.
22
.
10
511 -
=
delta
R
trimdown
(
)
[ ]
%
100
_
-
=
Vo
Vo
req
Vo
delta
22
.
10
225
.
1
626
511
)
100
(
-
-
+
=
delta
Vo
delta
R
trimup
Rtrimdown
Vo
Trim
GND
Module
Vo
Trim
GND
Module
Rtrimup
Bel Fuse Inc.
206 Van Vorst Street, Jersey City, NJ 07302
Tel 201-432-0463 Fax 201-432-9542 www.belfuse.com
ISOLATED DC/DC CONVERTERS
48V Input 3.3V/15A, 5V/12A, 12V/5A Outputs, 1/16 Brick Converter
Efficiency Data
70%
72%
74%
76%
78%
80%
82%
84%
86%
88%
90%
92%
94%
1.5A
3.75A
7.5A
11.25A
15A
OUTPUT CURRENT (A)
E
FFI
C
I
EN
CY
36V
48V
75V
S7SB-50T03x
Thermal Derating Curve
S7SB-50T03x
2005 Bel Fuse Inc. Specifications subject to change without notice. 021805
CORPORATE FAR
EAST
EUROPE
Bel Fuse Inc.
Bel Fuse Ltd.
Bel Fuse Europe Ltd.
206 Van Vorst Street
8F/ 8 Luk Hop Street
Preston Technology Management Centre
Jersey City, NJ 07302
San Po Kong
Marsh Lane, Suite G7, Preston
Tel 201-432-0463
Kowloon, Hong Kong
Lancashire, PR1 8UD, U.K.
Fax 201-432-9542
Tel 852-2328-5515
Tel 44-1772-556601
www.belfuse.com
Fax 852-2352-3706
Fax 44-1772-888366
www.belfuse.com
www.belfuse.com
ISOLATED DC/DC CONVERTERS
48V Input 3.3V/15A, 5V/12A, 12V/5A Outputs, 1/16 Brick Converter
Pin Connections
Pin
Function
1 Vin
(+)
2 Remote
On/Off
3 Vin
(-)
4 Vout-
5
Remote Sense (-)
6 Trim
7
Remote Sense (+)
8 Vout
(+)
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