Bel Fuse Inc.
206 Van Vorst Street, Jersey City, NJ 07302
Tel 201-432-0463 Fax 201-432-9542 www.belfuse.com
NON-ISOLATED DC/DC CONVERTERS
5.4 V - 13.2 V Input / 1.0 V - 5.0 V Output / 20 A
Non-Isolated
Wide
Input
OCP/SCP/OVP
Remote
Sense
Low
Profile
Package
Under-Voltage
Lockout
Remote On/Off (Active High)
(UVLO)
Description
The Bel SRDB-20ExxH is part of the non-isolated dc/dc converter Power Module series. The modules use a DIP
package for ease of layout and space savings. The output is closely regulated and the efficiency of 5 V output
module is typically 94% at full load.
Part Selection
Output
Voltage
Input
Voltage
Max. Output
Current
Max. Output
Power
Typical
Efficiency
Model Number
5.0 V
8.0 V - 13.2 V
20 A
100 W
94%
SRDB-20E50H
3.3 V
5.8 V - 13.2 V
20 A
66 W
92%
SRDB-20E33H
2.5 V
5.4 V - 13.2 V
20 A
50 W
91%
SRDB-20E25H
1.8 V
5.4 V - 13.2 V
20 A
36 W
88%
SRDB-20E18H
1.5 V
5.4 V - 13.2 V
20 A
30 W
87%
SRDB-20E15H
1.2 V
5.4 V - 13.2 V
20 A
24 W
85%
SRDB-20E12H
1.0 V
5.4 V - 13.2 V
20 A
20 W
84%
SRDB-20E10H
Note:
Add "R" suffix at the end of the model number to indicate "Reel Packaging", and "G" for "Tray Packaging".
Absolute Maximum Ratings
Parameter
Min
Typ
Max
Notes
Input Voltage (continuous)
-0.3 V
-
16 V
Output Enable Terminal Voltage
-0.3 V
-
16 V
Ambient Temperature
-40
C
-
85
C
Storage Temperature
-40
C
-
125
C
Input Specifications
Parameter
Min
Typ
Max
Notes
Input Voltage
Vo=5.0 V
Vo=3.3 V
Vo=1.0-2.5 V
8 V
5.8 V
5.4 V
-
-
-
13.2 V
13.2 V
13.2 V
Input Current (full load)
V
O
=5.0 V
V
O
=3.3 V
V
O
=2.5 V
V
O
=1.8 V
V
O
=1.5 V
V
O
=1.2 V
V
O
=1.0 V
-
-
-
-
-
-
-
-
-
-
-
-
-
-
15.1 A
14.1 A
13.3 A
10.4 A
8.4 A
6.9 A
5.9 A
SRDB-20ExxH Series RoHS Compliant
Bel Fuse Inc.
206 Van Vorst Street, Jersey City, NJ 07302
Tel 201-432-0463 Fax 201-432-9542 www.belfuse.com
NON-ISOLATED DC/DC CONVERTERS
5.4 V - 13.2 V Input / 1.0 V - 5.0 V Output / 20 A
Input Specifications (continued)
Parameter
Min
Typ
Max
Notes
Input Current (no load)
V
O
=5.0 V
V
O
=3.3 V
V
O
=2.5 V
V
O
=1.8 V
V
O
=1.5 V
V
O
=1.2 V
V
O
=1.0 V
-
-
-
-
-
-
-
200 mA
150 mA
135 mA
120 mA
100 mA
85 mA
80 mA
-
-
-
-
-
-
-
Input Reflected Ripple Current (pk-pk)
-
130 mA
200 mA
Input Reflected Ripple Current (rms)
-
40 mA
70 mA
With simulated impedance of
500 nH, 5 Hz to 20 MHz; use two
270 uF/16 V capacitors with
ESR=0.018ohm max, at 100 kHz
I
2
t Inrush Current Transient
-
0.1 A
2
s 0.2
A
2
s
Turn-on Voltage Threshold
4.35 V
4.48 V
4.60 V
Turn-off Voltage Threshold
3.65 V
3.98 V
4.30 V
Note:
All specifications are typical at Vin=8 V, full load at 25
C
unless otherwise stated.
Output Specifications
Parameter
Min
Typ
Max
Notes
Output Voltage Set Point
V
O
=5.0 V
V
O
=3.3 V
V
O
=2.5 V
V
O
=1.8 V
V
O
=1.5 V
V
O
=1.2 V
V
O
=1.0 V
4.900 V
3.234 V
2.450 V
1.764 V
1.470 V
1.176 V
0.980 V
5.0 V
3.3 V
2.5 V
1.8 V
1.5 V
1.2 V
1.0 V
5.100 V
3.366 V
2.550 V
1.836 V
1.530 V
1.224 V
1.020 V
Test conditions:
Vin=8 V; Iout=half load
Line Regulation
V
O
=5.0 V
V
O
=3.3 V
V
O
=2.5 V
V
O
=1.8 V
V
O
=1.5 V
V
O
=1.2 V
V
O
=1.0 V
-
-
-
-
-
-
-
2 mV
1 mV
1 mV
1 mV
1 mV
1 mV
1 mV
4 mV
3 mV
3 mV
3 mV
3 mV
3 mV
3 mV
Load Regulation
V
O
=5.0 V
V
O
=3.3 V
V
O
=2.5 V
V
O
=1.8 V
V
O
=1.5 V
V
O
=1.2 V
V
O
=1.0 V
-
-
-
-
-
-
-
3 mV
2 mV
2 mV
2 mV
1 mV
1 mV
1 mV
7 mV
4 mV
4 mV
4 mV
3 mV
3 mV
3 mV
Regulation Over Temperature
(-40
C to +85 C)
V
O
=5.0 V
V
O
=3.3 V
V
O
=2.5 V
V
O
=1.8 V
V
O
=1.5 V
V
O
=1.2 V
V
O
=1.0 V
-
-
-
-
-
-
-
15 mV
10 mV
9 mV
8 mV
7 mV
5 mV
5 mV
30 mV
20 mV
18 mV
16 mV
14 mV
10 mV
10 mV
Bel Fuse Inc.
206 Van Vorst Street, Jersey City, NJ 07302
Tel 201-432-0463 Fax 201-432-9542 www.belfuse.com
NON-ISOLATED DC/DC CONVERTERS
5.4 V - 13.2 V Input / 1.0 V - 5.0 V Output / 20 A
Output Specifications (continued)
Parameter
Min
Typ
Max
Notes
Output Current
0 A
-
20 A
Current Limit Threshold
24 A
-
40 A
Short Circuit Surge Transient
-
0.075 A
2
s
0.15 A
2
s
Ripple and Noise
1
(rms)
-
20 mV
40 mV
With 1 uF ceramic capacitor at the
output
Ripple and Noise
1
(rms)
-
10 mV
20 mV
With 680 uF tantalum capacitor at the
output
Ripple and Noise
1
(pk-pk)
60 mV
100 mV
With 1 uF ceramic capacitor at the
output
Ripple and Noise
1
(pk-pk)
30 mV
60 mV
With 680 uF tantalum capacitor at the
output
Turn on Time
-
20 mS
40 mS
Overshoot at Turn on
-
0%
3%
Output Capacitance
680 uF
-
8000 uF
Transient Response
50% ~ 100% Max Load
-
120 mV
200 mV
Settling Time
-
50 uS
100 uS
100% ~ 50% Max Load
-
120 mV
200 mV
Settling Time
V
O
=5 V
- 50
uS
100 uS
50% ~ 100% Max Load
-
100 mV
150 mV
Settling Time
-
50 uS
100 uS
100% ~ 50% Max Load
-
100 mV
150 mV
Settling Time
V
O
=1.8 V-
3.3 V
-
50 uS
100 uS
50% ~ 100% Max Load
-
100 mV
150 mV
Settling Time
-
40 uS
80 uS
100% ~ 50% Max Load
-
100 mV
150 mV
Settling Time
V
O
=1.5 V
-
40 uS
80 uS
50% ~ 100% Max Load
-
100 mV
150 mV
Settling Time
-
40 uS
80 uS
100% ~ 50% Max Load
-
100 mV
150 mV
Settling Time
V
O
=1.2 V
-
50 uS
100 uS
50% ~ 100% Max Load
-
90 mV
130 mV
Settling Time
-
40uS
80 uS
100% ~ 50% Max Load
-
90 mV
130 mV
Settling Time
V
O
=1.0 V
-
40 uS
80 uS
Test conditions:
di/dt = 0.5 A/uS; Vin=8 V; with
external 680 uF tantalum capacitor.
Notes:
All specifications are typical at full load at 25
C
u nless otherwise stated.
1. Test conditions of the output ripple and noise: two 270 uF/16 V capacitors with ESR=0.018 ohm max
at the input; Vin=8 V, Io=20 A; 0-20 MHz BW.
Bel Fuse Inc.
206 Van Vorst Street, Jersey City, NJ 07302
Tel 201-432-0463 Fax 201-432-9542 www.belfuse.com
NON-ISOLATED DC/DC CONVERTERS
5.4 V - 13.2 V Input / 1.0 V - 5.0 V Output / 20 A
General Specifications
Parameter
Min
Typ
Max
Notes
Efficiency
V
O
=5.0 V
V
O
=3.3 V
V
O
=2.5 V
V
O
=1.8 V
V
O
=1.5 V
V
O
=1.2 V
V
O
=1.0 V
91%
89%
88%
85%
84%
82%
81%
94%
92%
91%
88%
87%
85%
84%
-
-
-
-
-
-
-
Measured at Vin=8 V at full load.
Switching Frequency
480 kHz
600 kHz
720 kHz
Over Voltage Protection (Latch)
108.5%
115%
120%
Can be reset by cycling the input supply
voltage or remote on/off.
Output Trim Range
90%V
O
- 110%V
O
Remote Sense Compensation
-
10%
MTBF
3,154,461 hours
Calculated Per Bell Core SR-332 (I
O
=
16 A, Vin=8 V, Vo=3.3 V; T
a
= 25
C)
Dimensions
Inches (L W H)
Millimeters (L W H)
1.22 x 0.827 x 0.345
30.99 x 21.0 x 8.76
Weight -
11
g
-
Note
: All specifications are typical at 25
C
unless otherwise stated.
Control Specifications
Parameter
Min
Typ
Max
Notes
Remote On/Off
Signal Low (Unit Off)
0 V
-
1 V
Signal High (Unit On)
2.5 V
-
13.2 V
Remote on/off pin open, unit on.
Output Trim Equations
Equations for calculating the trim resistor (in k) given the desired adjusted voltage (Vadj) and the nominal
output voltage of the converter (Vnom) are shown below. The Trim Down resistor should be connected between
the Trim pin and Vout. The Trim Up resistor should be connected between the Trim pin and Ground. Only one of
the resistors should be used for any given application.
Vnom A B
C D
5.0V 30.955 15.805 5.884 8.450
3.3V 3.961 3.407 1.266 1.825
2.5V 1.834 3.397 0.861 2.320
1.8V 1.927 6.916 1.533 5.000
1.5V 1.353 5.851 1.533 3.935
1.2V 0.099 0.446 0.196 0.201
1.0V 0.102 0.684 0.401 0.183
K
B
Vadj
Vnom
A
down
Rtrim
)
(
_
-
-
=
D
Vnom
Vadj
C
up
Rtrim
)
(
_
-
-
=
Module
Vout
Trim
GND
Rtrimdown
Module
Vout
Trim
GND
Rtrimup
Bel Fuse Inc.
206 Van Vorst Street, Jersey City, NJ 07302
Tel 201-432-0463 Fax 201-432-9542 www.belfuse.com
NON-ISOLATED DC/DC CONVERTERS
5.4 V - 13.2 V Input / 1.0 V - 5.0 V Output / 20 A
Efficiency Data
Efficiency Curve
72.0%
76.0%
80.0%
84.0%
88.0%
92.0%
96.0%
100.0%
2
4
6
8
10
12
14
16
18
20
Output Current (A)
E
f
f
i
c
i
en
cy
8.0 V
10.8 V
13.2 V
Efficiency Curve
68.0%
72.0%
76.0%
80.0%
84.0%
88.0%
92.0%
96.0%
100.0%
2
4
6
8
10
12
14 16
18
20
Output Current (A)
E
f
f
i
ci
e
n
cy
5.8 V
8.0 V
13.2 V
Vo=5.5 V Vo=3.3 V
Efficiency Curve
70.0%
74.0%
78.0%
82.0%
86.0%
90.0%
94.0%
98.0%
2
4
6
8
10 12
14
16
18
20
Output Current (A)
E
f
f
i
ci
en
cy
5.4 V
8.0 V
13.2 V
Efficiency Curve
68.0%
72.0%
76.0%
80.0%
84.0%
88.0%
92.0%
2
4
6
8
10
12
14
16
18
20
Output Current (A)
Effi
c
i
e
n
c
y
5.4 V
8.0 V
13.2 V
Vo=2.5 V Vo=1.8 V
Efficiency Curve
66.0%
70.0%
74.0%
78.0%
82.0%
86.0%
90.0%
94.0%
2
4
6
8
10
12
14
16
18
20
Output Current (A)
E
f
f
i
ci
e
n
cy
5.4 V
8.0 V
13.2 V
Efficiency Curve
64.0%
68.0%
72.0%
76.0%
80.0%
84.0%
88.0%
92.0%
2
4
6
8
10
12
14
16
18
20
Output Current (A)
E
f
f
i
ci
en
cy
5.4 V
8.0 V
13.2 V
Vo=1.5V Vo=1.2 V
Efficiency Curve
60.0%
64.0%
68.0%
72.0%
76.0%
80.0%
84.0%
88.0%
92.0%
2
4
6
8
10
12
14
16
18
20
Output Current (A)
E
f
f
i
ci
en
cy
5.4 V
8.0 V
13.2 V
Vo=1.0 V
Bel Fuse Inc.
206 Van Vorst Street, Jersey City, NJ 07302
Tel 201-432-0463 Fax 201-432-9542 www.belfuse.com
NON-ISOLATED DC/DC CONVERTERS
5.4 V - 13.2 V Input / 1.0 V - 5.0 V Output / 20 A
Thermal Derating Curves
SRDB-20E10H (Vin=8 V) SRDB-20E12H (Vin=8 V)
SRDB-20E15H (Vin=8 V) SRDB-20E18H (Vin=8 V)
SRDB-20E25H (Vin=8 V) SRDB-20E33H (Vin=8 V)
SRDB-20E50H (Vin=8 V)
2005 Bel Fuse Inc. Specifications subject to change without notice. 111705
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
NON-ISOLATED DC/DC CONVERTERS
5.4 V - 13.2 V Input / 1.0 V - 5.0 V Output / 20 A
Mechanical Outline
Note:
Though there are 5 GND pins (3,4,5,8,9), it is highly recommended that all of them should be used in the system
application, because of the current and the thermal conduction.
RoHS Compliance
Complies with the European Directive 2002/95/EC, calling for the elimination of lead and
other hazardous substances from electronic products. These parts are not however
compatible with the higher temperatures associated with lead free solder processes and
must be soldered using a reflow profile with a peak temperature of no more than 240C.
Pin Connections
Pin
Function
1 +Vo
2 +Vo
3 Ground
4 Ground
5 Ground
6 +Vin
7 +Vin
8 Ground
9 Ground
10 Remote
On/Off
11 Trim
12
Remote Sense (+)
PDF 
ZIP