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
3.3 Vdc Input 0.9 Vdc - 2.5 Vdc/3 A Output
• Non-Isolated • OCP/SCP
• High Efficiency • Wide Range Trim
• Low Cost • Remote On/Off
• Excellent Thermal Performance • Industrial Temperature Range
• Input Under Voltage Lockout • UL60950-1 Recognized (UL/cUL)
Description
The Bel xRAH-03C1A0 modules are a series of non-isolated, step down dc/dc converters that operate from a
nominal 3.3 Vdc source. These converters are available in a range of output voltages from 0.9 Vdc to 2.5 Vdc. It
is packaged in a compact, overmolded package rated at 3 A. Optional lead forming provides a vertical mount
product for minimal footprint or a surface mount option for a very low profile. The output is closely regulated and
the efficiency for 2.5 Vdc output is typically 93% at full load. Typical features include remote on/off, input under
voltage lockout, over current protection and short circuit protection.
Part Selection
Output Voltage Input
Voltage Max. Output
Current Max. Output
Power Typical
Efficiency Part Number
Surface Mount Part Number
Vertical Mount
0.9 Vdc - 2.5 Vdc 3.3 Vdc 3 A 7.5 W 93% SRAH-03C1A0 VRAH-03C1A0
2.5 Vdc 3.3 Vdc 3 A 7.5 W 93% SRAH-03C250 VRAH-03C250
1.8 Vdc 3.3 Vdc 3 A 5.4 W 89% SRAH-03C180 VRAH-03C180
1.5 Vdc 3.3 Vdc 3 A 4.5 W 87% SRAH-03C150 VRAH-03C150
1.2 Vdc 3.3 Vdc 3 A 3.6 W 84% SRAH-03C120 VRAH-03C120
0.9 Vdc 3.3 Vdc 3 A 2.7 W 81% SRAH-03C090 VRAH-03C090
Notes: 1. Add “0” suffix at the end of the model number to indicate “Tube Packaging”, and “R” for “Reel
Packaging”, and “G” for “Tray Packaging”.
2. All part numbers above indicate RoHS 6. Change the second letter "R" to "7" for RoHS 5 part numbers.
Absolute Maximum Ratings
Parameter Min Typ Max Notes
Input Voltage (continuous) -0.3 V - 6 V
Output Enable Terminal Voltage -0.3 V - 6 V
Ambient Temperature -40 °C - 85 °C
Storage Temperature -55 °C - 125 °C
Input Specifications
Parameter Min Typ Max Notes
Input Voltage 3 V - 3.6 V
Input Current (no load) - - 110mA
Input Current (full load)
VO=2.5 V
VO=1.8 V
VO=1.5 V
VO=1.2 V
VO=0.9 V
-
-
-
-
-
-
-
-
-
-
3.1 A
2.3 A
1.9 A
1.6 A
1.2 A
Remote Off Input Current - 7 mA 14 mA
xRAH-03C Series RoHS Com
p
liant Rev.A
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
3.3 Vdc Input 0.9 Vdc - 2.5 Vdc/3 A Output
Input Specifications (continued)
Parameter Min Typ Max Notes
Input Reflected Ripple Current (pk-pk) - 50 mA 100 mA
Input Reflected Ripple Current (rms) - 15 mA 25 mA
With simulated source impedance
of 500 nH, 5 Hz to 20 MHz; use a
270 uF/6.3 V capacitor with
ESR=0.03 ohm max, at 100 kHz.
I2t Inrush Current Transient - 0.01 A2s 0.02 A2s
Turn on Voltage Threshold - 2.7 V -
Turn off Voltage Threshold - 2.4 V -
Note: All specifications are typical at 25 °C unless otherwise stated.
Output Specifications
Parameter Min Typ Max Notes
Output Voltage Set Point
VO=2.5 V
VO=1.8 V
VO=1.5 V
VO=1.2 V
VO=0.9 V
2.450 V
1.764 V
1.470 V
1.176 V
0.882 V
2.5 V
1.8 V
1.5 V
1.2 V
0.9 V
2.550 V
1.836 V
1.530 V
1.224 V
0.918 V
Test conditions:
Vin=3.3 V, Io= full load
Line Regulation
VO=2.5 V
VO=1.8 V
VO=1.5 V
VO=1.2 V
VO=0.9 V
-
-
-
-
-
1 mV
1 mV
1 mV
1 mV
1 mV
5 mV
5 mV
5 mV
5 mV
5 mV
Load Regulation
VO=2.5 V
VO=1.8 V
VO=1.5 V
VO=1.2 V
VO=0.9 V
-
-
-
-
-
1 mV
1 mV
1 mV
1 mV
1 mV
5 mV
5 mV
5 mV
5 mV
5 mV
Regulation Over Temperature
(-40 °C to +85 °C)
VO=2.5 V
VO=1.8 V
VO=1.5 V
VO=1.2 V
VO=0.9 V
-
-
-
-
-
10 mV
10 mV
10 mV
10 mV
10 mV
20 mV
20 mV
20 mV
20 mV
20 mV
Output Current 0 A - 3 A
Current Limit Threshold 5 A - 9 A
Short Circuit Surge Transient
VO=2.5 V
VO=1.8 V
VO=1.5 V
VO=1.2 V
VO=0.9 V
-
-
-
-
-
0.04 A2s
0.04 A2s
0.04 A2s
0.04 A2s
0.04 A2s
0.08 A2s
0.08 A2s
0.08 A2s
0.08 A2s
0.08 A2s
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
3.3 Vdc Input 0.9 Vdc - 2.5 Vdc/3 A Output
Output Specifications (continued)
Parameter Min Typ Max Notes
Ripple and Noise (rms)
VO=2.5 V
VO=1.8 V
VO=1.5 V
VO=1.2 V
VO=0.9 V
-
-
-
-
-
10 mV
10 mV
10 mV
10 mV
10 mV
20 mV
20 mV
20 mV
20 mV
20 mV
Ripple and Noise (pk-pk)
VO=2.5 V
VO=1.8 V
VO=1.5 V
VO=1.2 V
VO=0.9 V
-
-
-
-
-
45 mV
45 mV
45 mV
45 mV
45 mV
70 mV
70 mV
70 mV
70 mV
70 mV
Test conditions:
0-20 MHz BW; 0.1 uF ceramic
capacitor and
10 uF tantalum capacitor at the
output.
Turn on Time - 7 mS 15 mS
Overshoot at Turn on - 0% 1%
Output Capacitance 0 uF - 1200 uF
Transient Response
Overshoot - 100 mV 130 mV
50% ~ 100%
Max Load Settling Time - 30 uS 60 uS
Overshoot - 100 mV 130 mV
100% ~ 50%
Max Load Settling Time
VO=2.5 V
- 30 uS 60 uS
Overshoot - 100 mV 130 mV
50% ~ 100%
Max Load Settling Time - 30 uS 60 uS
Overshoot - 100 mV 130 mV
100% ~ 50%
Max Load Settling Time
VO=1.8 V
- 30 uS 60 uS
Overshoot - 90 mV 120 mV
50% ~ 100%
Max Load Settling Time - 30 uS 60 uS
Overshoot - 90 mV 120 mV
100% ~ 50%
Max Load Settling Time
VO=1.5 V
- 30 uS 60 uS
Overshoot - 90 mV 120 mV
50% ~ 100%
Max Load Settling Time - 30 uS 60 uS
Overshoot - 90 mV 120 mV
100% ~ 50%
Max Load Settling Time
VO=1.2 V
- 30 uS 60 uS
Overshoot - 90 mV 120 mV
50% ~ 100%
Max Load Settling Time - 30 uS 60 uS
Overshoot - 90 mV 120 mV
100% ~ 50%
Max Load Settling Time
VO=0.9 V
- 30 uS 60 uS
Test conditions:
di/dt=0.5 A/us, Vin=3.3 V,
without any external
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
3.3 Vdc Input 0.9 Vdc - 2.5 Vdc/3 A Output
General Specifications
Parameter Min Typ Max Notes
Efficiency
VO=2.5 V
VO=1.8 V
VO=1.5 V
VO=1.2 V
VO=0.9 V
90%
86%
84%
81%
78%
93%
89%
87%
84%
81%
-
-
-
-
-
Measured at Vin=3.3 V, full load and
Ta=25 °C
Switching Frequency 250 kHz 300 kHz 340 kHz
Output Trim Range (wide trim) 0 - 292%VO Vo=0.9 V
Output Trim Range (narrow trim)
Vo=1.2 V - 2.5 V
Vo=0.9 V
90%Vo
-
-
-
110%Vo
110%Vo
MTBF 3,131,719 hours Calculated Per Bell Core SR-332 (IO =
Nominal; Ta = 25 °C)
Dimensions (surface mount)
Inches (L × W × H)
Millimeters
(
L × W × H
)
0.78 x 0.70 x 0.32
19.81 x 17.78 x 8.13
Dimensions (vertical)
Inches (L × W × H)
Millimeters
(
L × W × H
)
0.70 x 0.308 x 0.65
17.78 x 7.82 x 16.51
Weight - 5 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 - 0.3 V
Signal High (Unit On) 1.8 V - 3.6 V
Remote on/off pin open, unit on.
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
3.3 Vdc Input 0.9 Vdc - 2.5 Vdc/3 A Output
Output Trim Equations
Equations for calculating the trim resistor (in kΩ) 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
VV A
R
adjnom
trimdown −
−
=
D
VV C
R
nomadj
trimup −
−
=
Vnom A B C D Notes
0.9 - 2.5 N/A N/A 3.712 1.54 Vo=0.9 V when Rtrim is open
2.5 7.9117 16.14 3.712 11.5 Vo=2.505 V when Rtrim is open
1.8 4.6538 20.84 3.712 16.2 Vo=1.803 V when Rtrim is open
1.5 3.2633 16.14 3.712 11.5 Vo=1.503 V when Rtrim is open
1.2 1.8699 11.45 3.712 6.81 Vo=1.203 V when Rtrim is open
0.9 N/A N/A 3.712 33.2 Vo=0.903 V when Rtrim is open
Module
Vout
Trim
GND
Rtrimdown
Module
Vout
Trim
GND Rtri m u p
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
3.3 Vdc Input 0.9 Vdc - 2.5 Vdc/3 A Output
Efficiency Data
MODULE 2.5V
60%
70%
80%
90%
100%
0.30.751.52.25 3
OUTPUT CURRENT
EFFICIENC
Y
3.0V
3.3V
3.6V
MODULE 1.8V
60%
70%
80%
90%
100%
0.3 0.75 1.5 2.25 3
OUTPUT C U R R EN T
EFFICIENCY
3.0V
3.3V
3.6V
MOD ULE 1.5V
50%
60%
70%
80%
90%
100%
0.3 0.75 1.5 2.25 3
OUTPUT CURRETN
EFFICIENC
Y
3.0V
3.3V
3.6V
MODULE 1.2V
50%
60%
70%
80%
90%
100%
0.3 0.75 1.5 2.25 3
OUTPUT CURRENT
EFFICIENC
Y
3.0V
3.3V
3.6V
MODULE 0.9V
40%
60%
80%
100%
0.3 0.75 1.5 2.25 3
OUTPUT CURRENT
EFFICIENC
Y
3.0V
3.3V
3.6V
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
3.3 Vdc Input 0.9 Vdc - 2.5 Vdc/3 A Output
Thermal Derating Curve
Ripple and Noise Waveform
Ripple and noise at full load, 3.3 V input, 2.5 V output
Note: Ripple and Noise with 0.1 uF/16 V X7R ceramic capacitor and 10 uF tantalum capacitor at the 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
NON-ISOLATED DC/DC CONVERTERS
3.3 Vdc Input 0.9 Vdc - 2.5 Vdc/3 A Output
Transient Response Waveforms
50% to 100% load Transient at 3.3 V input, 2.5 V output
100% to 50% load Transient at 3.3 V input, 2.5 V output
Note: Transient Response at di/dt=0.5A/uS, Ta=25 deg C.
©
2007 Bel Fuse Inc. Specifications subject to change without notice. 010807
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
3.3 Vdc Input 0.9 Vdc - 2.5 Vdc/3 A Output
Mechanical Outline
SRAH-03C1A0
VRAH-03C1A0
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 240 ºC.
Pin Connections
Pin Function
1 Remote On/Off (option)
2 Vin
3 Ground
4 Vout
5 Trim (option)
6 N/A
7 N/A
Pin Connections
Pin Function
1 Remote On/Off (option)
2 Vin
3 Ground
4 Vout
5 Trim (option)
