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
3.0 Vdc - 5.5 Vdc Input
12 Vdc/0.8 A & 15 Vdc/0.6 A Output
Non-Isolated
Trim Function (option)
Fixed Frequency (550 kHz)
High
Efficiency
Low
Profile
Package
Allows Burst Mode Operation
at Low Load Currents
UL60950
Recognized
(UL/cUL)
Description
The Bel xRAH-01FXx0 is part of the low cost non-isolated dc/dc converter series. The modules use a surface
mount package or vertical package for ease of layout and space savings. The output is closely regulated and
the efficiency of 12 Vdc output module is typically 88% at full load. Typical features include burst mode
operation at light load and trim function (option).
Part Selection
Output
Voltage
Input Voltage
Max. Output
Current
Max. Output
Power
Typical
Efficiency
Part Number
Surface Mount
Part Number
Vertical Mount
12 Vdc
3.0 Vdc - 5.5 Vdc
0.8 A
9.6 W
88%
SRAH-01FX20
VRAH-01FX20
15 Vdc
3.0 Vdc - 5.5 Vdc
0.6 A
9.0 W
88%
SRAH-01FX50
VRAH-01FX50
Note:
Add "0" suffix at the end of the model number to indicate "Tube Packaging", and "R" for "Reel Packaging",
and "G" for "Tray Packaging".
Absolute Maximum Ratings
Parameter
Min
Typ
Max
Notes
Input Voltage (continuous)
2.8 V
-
6 V
Ambient Temperature
-40
C
-
85
C
Storage Temperature
-40
C
-
125
C
Input Specifications
Parameter
Min
Typ
Max
Notes
Input Voltage
3 V
-
5.5 V
Input Current (full load)
V
O
=12 V
V
O
=15 V
-
-
-
-
4.3 A
4.0 A
Input Reflected Ripple Current (pk-pk)
-
100 mA
150 mA
Input Reflected Ripple Current (rms)
-
30 mA
60 mA
With simulated source impedance
of 500 nH, 5 Hz to 20 MHz; Use
270 uF/16 V Oscon capacitor with
ESR = 0.018 ohm max. at 100 kHz
I
2
t Inrush Current Transient
-
0.02 A
2
s 0.05
A
2
s
Turn-on Voltage Threshold
-
2.8 V
2.9 V
Note
: All specifications are typical at 25
C
unless otherwise stated.
xRAH-01FXx0 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
3.0 Vdc - 5.5 Vdc Input
12 Vdc/0.8 A & 15 Vdc/0.6 A Output
Output Specifications
Parameter
Min
Typ
Max
Notes
Output Voltage Set Point
V
O
=12 V
V
O
=15 V
11.580 V
14.475 V
12 V
15 V
12.420 V
15.525 V
Test condition:
Vin=5 V, lout=full load
Line Regulation
V
O
=12 V
V
O
=15 V
-
-
20 mV
20 mV
40 mV
40 mV
Load Regulation
V
O
=12 V
V
O
=15 V
-
-
60 mV
75 mV
120 mV
150 mV
Regulation Over Temperature
(-40
C to +85 C)
V
O
=12 V
V
O
=15 V
-
-
45 mV
60 mV
80 mV
100 mV
Output Current
V
O
=12 V
V
O
=15 V
0 A
0 A
-
-
0.8 A
0.6 A
Ripple and Noise (rms)
V
O
=12 V; I
O
=0 A
V
O
=15 V; I
O
=0 A
V
O
=12 V; I
O
=0.8 A
V
O
=15 V; I
O
=0.6 A
-
-
-
-
5 mV
5 mV
20 mV
30 mV
10 mV
10 mV
40 mV
50 mV
Ripple and Noise (pk-pk)
V
O
=12 V; I
O
=0 A
V
O
=15 V; I
O
=0 A
V
O
=12 V; I
O
=0.8 A
V
O
=15 V; I
O
=0.6 A
-
-
-
-
20 mV
20 mV
60 mV
80 mV
40 mV
40 mV
100 mV
120 mV
Test conditions:
BW = 0-20 MHz; 1uF
ceramic cap and 33 uF
Tantalum capacitor at the
output.
Rise Time
-
5 mS
-
Overshoot at Turn on
-
0%
5%
Output Capacitance
33 uF
-
330 uF
The min output
capacitance is 33 uF
Tantalum capacitor at the
output
Transient Response
Overshoot
-
130 mV
200 mV
50% ~ 100%
Max Load
Settling Time
-
100 uS
200 uS
Overshoot
-
130 mV
200 mV
100% ~ 50%
Max Load
Settling Time
All
Outputs
- 100
uS
200 uS
di/dt = 0.1 A/uS; Vin = 5 V;
and with 33 uF 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
NON-ISOLATED DC/DC CONVERTERS
3.0 Vdc - 5.5 Vdc Input
12 Vdc/0.8 A & 15 Vdc/0.6 A Output
General Specifications
Parameter
Min
Typ
Max
Notes
Efficiency
V
O
=12 V
V
O
=15 V
84%
84%
88%
88%
-
-
Measured at Vin=5 V, full load
Switching Frequency
500 kHz
550 kHz
650 kHz
Output Trim Range
90% V
O
- 110%
V
O
MTBF
13,684,605 hours
Calculated Per Bell Core SR-332 (Vin=
5 V; Vo=12 V; I
O
= 0.64 A; T
a
= 25
C)
Dimensions (surface mount)
Inches (L W H)
Millimeters (L W H)
0.78 x 0.7 x 0.32
19.81 x 17.78 x 8.13
Dimensions (vertical)
Inches (L W H)
Millimeters (L W H)
0.7 x 0.308 x 0.65
17.78 x 7.82 x 16.51
Weight -
5.2
g
-
Note
: All specifications are typical at 25
C
unless otherwise stated.
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.
B
V
V
A
R
adj
nom
down
trim
-
-
=
-
D
V
V
C
R
nom
adj
up
trim
-
-
=
-
Vnom
A B C D
12 164.640
21.850
11.760 7.150
15.055 209.542 20.600 11.760 5.900
Vout
Trim
GND
Rtrim-down
Module
Vout
Trim
GND
Rtrim-up
Module
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
3.0 Vdc - 5.5 Vdc Input
12 Vdc/0.8 A & 15 Vdc/0.6 A Output
Efficiency Data
Efficiency Curve
78.0%
80.0%
82.0%
84.0%
86.0%
88.0%
90.0%
92.0%
0.08
0.20
0.40
0.60
0.80
Output Current (A)
E
f
f
i
ci
en
c
y
3.0 V
5.0 V
5.5 V
Efficiency Curve
70.0%
75.0%
80.0%
85.0%
90.0%
95.0%
0.06
0.15
0.30
0.45
0.60
Output Current (A)
E
f
f
i
ci
en
c
y
3.0 V
5.0 V
5.5 V
xRAH-01FX20 xRAH-01FX50
Thermal Derating Curves
xRAH-01FX20 xRAH-01FX50
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
3.0 Vdc - 5.5 Vdc Input
12 Vdc/0.8 A & 15 Vdc/0.6 A Output
Ripple and Noise Waveforms
Ripple and noise at full load, Vin=5 V, Vo=12 V Ripple and noise at no load, Vin=5 V, Vo=12 V
Ripple and noise at full load, Vin=5 V, Vo=15 V Ripple and noise at no load, Vin=5 V, Vo=15 V
Note
:
Ripple and noise tested with 1 uF ceramic capacitor and 33 uF tantalum capacitor at the output,
Ta=25 deg C.
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