
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
12 Vdc Input
0.9 Vdc - 5.0 Vdc/20 A Output
General Specifications
Parameter
Min
Typ
Max
Notes
Efficiency (Current Source)
Vo=5.0 V
Vo=3.3 V
Vo=2.5 V
Vo=0.9 V
89%
86%
83%
65%
92%
89%
86%
69%
-
Efficiency (Current Sink)
Vo=2.5 V
Vo=0.9 V
79%
60%
82%
63%
-
Measured at Vin=12 V, full load.
Switching Frequency
240 kHz
275 kHz
310 kHz
Output Voltage Trim Range
0.9 V
-
5.0 V
Vo=0.9 V when the Trim pin is open.
MTBF
5,570,000 hours
Calculated Per Bell Core SR-332 (IO =
Nominal; Ta = 25
°C)
Dimensions
Inches (L × W × H)
Millimeters (L × W × H)
1.2 x 1.1 x 0.457
30.48 x 27.94 x 11.6
VRPF-20A1A0
Dimensions
Inches (L × W × H)
Millimeters (L × W × H)
1.2 x 1.1 x 0.508
30.48 x 27.94 x 12.91
0RPF-20A1A0
Weight
-
15 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)
-0.3 V
-
0.8 V
Signal High (Unit On)
2.4 V
-
13.8 V
Remote On/Off pin open, unit on.
Power Good
Power Good Delay
1
-
8 mS
Note
: All specifications are typical at 25 °C unless otherwise stated.
1. The power good signal is an open collector output. When the output of the module reaches 90% of the
nominal set point, the power good pin is set high.
Output Trim Equations
Equation for calculating the trim resistor (in k) given the desired adjusted voltage (Vadj) is shown below. The
Trim Up resistor should be connected between the Trim pin and Ground. Trim values should not be less than
280.
9
.
0
17
.
1
=
adj
trim
V
R
Equation for calculating the trim voltage (in V) given the desired adjusted voltage (Vadj) is shown below. The
Trim Up voltage should be connected between the Trim pin and Ground.
)
9
.
0
(
17
.
1
)
17
.
1
3
.
1
(
×
×
=
adj
V
Rs
Vt
Rs
Rt
Rtrim
Module
Vout
GND
Trim
Vt
Module
Vout
GND
Trim
Rt
Rs