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 CONVERTER
5 V Input
Vref/2 / 5 A Output
Non-Isolated
Remote
On/Off
Fixed frequency (300 kHz)
OCP/SCP
Under-voltage lockout (UVLO)
Low Profile Package (7.82 mm)
Current
Sink
Capability
Description
The Bel xRAH-05BT50 is part of the low cost non-isolated dc/dc converter series. The converter is designed
specifically to provide bus termination voltage in application such as DDR (double data rate) memory where the
bus termination voltage must closely track the I/O bus voltage. The converter accepts a reference input and
programs its output voltage to 50% of the reference. The modules use a SMD or vertical mount package for
ease of layout and space savings.
Part Selection
Output
Voltage
Input
Voltage
Max. Output
Current
Max. Output
Power
Typical
Efficiency
Part Number
Surface Mount
Part Number
Vertical Mount
Vref/2
5 V
5 A
6.25 W
82%
SRAH-05BT50
VRAH-05BT50
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)
-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
4.5 V
5.0 V
5.5 V
Input Current
(Source) -
-
2
A
Input Current (Sink)
-1.5 A
Input Current (No load)
-
-
60 mA
Remote Off Input Current
-
9 mA
15 mA
Input Reflected Ripple Current
(rms)
-
30 mA
50 mA
Input Reflected Ripple Current
(pk-pk)
-
110 mA
140 mA
Measured with simulated source
impedance of 500 nH, 5 Hz to 20 MHz;
& one 270 uF/16 V 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
Vref Voltage
0 V
2.5 V
4 V
Turn-on Voltage Threshold
4.19 V
4.3 V
4.5 V
Turn Off Voltage threshold
-
3.8 V
4.49 V
Notes: 1. All tests are measured at Vref = 2.5 V.
2. All specifications are typical at 25
C unless otherwise stated.
xRAH-05BT50 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 CONVERTER
5 V Input
Vref/2 / 5 A Output
Output Specifications
Parameter
Min
Typ
Max
Notes
Output Voltage Set Point
0.99* (Vref/2) V
Vref/2
1.01* (Vref/2) V
Vin=5 V, Iout=full load.
Load Regulation
-
3 mV
6 mV
Line Regulation
-
1 mV
3 mV
Regulation Over Temperature
(-40
C to +85
C)
-
15 mV
20 mV
Output Current
0 A
-
5 A
Output Current Threshold
6.5 A
-
12.5 A
Short Circuit Surge Transient
-
0.04 A
2
s 0.08
A
2
s
Ripple and Noise (rms)
-
12 mV
20 mV
Ripple and Noise (pk-pk)
-
45 mV
90 mV
Tested at:
0-20 MHz BW;
with 1 uF ceramic
capacitor at the output
Turn On Time
-
12 mS
20 mS
Overshoot at Turn on
-
0%
3%
Output Capacitance
-
-
2200 uF
Notes: 1. All specifications are typical at nominal input, full load at 25
C unless otherwise stated.
2. The modules track the transient response of the reference input. See the figure in TR data on Page 3.
3. The turn-off undershoot of the module is below 100mV if a 220 uF aluminum cap is added at the output.
4. All tests are measured at Vref=2.5 V.
General Specifications
Parameter
Min
Typ
Max
Notes
Efficiency (source)
79%
82%
-
Measured at Vin=5V, lo=lo-max full load
Efficiency (sink)
78%
81%
-
Measured at Vin=5V, lo=lo-max full load
Switching Frequency
250 kHz
300 kHz
340 kHz
MTBF
8,841,119 hours
Calculated Per Bell Core SR-332 (I
O
=
4 A, Vin=5 V, Vref=2.5 V; T
a
= 25
C)
Dimensions (surface mount)
Inches (L
W
H)
Millimeters (L
W
H)
0.78 x 0.7 x 0.32
19.812 x 17.78 x 8.128
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 -
4.7
g
-
Note: All specifications are typical at nominal input, full load at 25
C unless otherwise stated. All tests are
measured at Vref=2.5 V.
Control Specifications
Parameter
Min
Typ
Max
Notes
Remote On/Off
-0.3 V
-
1.35V (Vin=4.5V)
Signal Low (Unit Off)
-0.3 V
-
1.65V (Vin=5.5V)
3.15 V(Vin=4.5V)
-
5.5 V
Signal High (Unit On)
3.85 V(Vin=5.5V)
-
5.5 V
Remote on/off pin open, unit on
Note: All tests are measured at Vref=2.5 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 CONVERTER
5 V Input
Vref/2 / 5 A Output
Transient Response
Track the transient response of the reference input. No External Load Capacitance.
Channel 1: Transient response
tracking.
Channel 2: Transient response
of the reference input.
Ta = 25
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 CONVERTER
5 V Input
Vref/2 / 5 A Output
Efficiency Data
Efficiency Curve
79.0%
80.0%
81.0%
82.0%
83.0%
84.0%
85.0%
86.0%
87.0%
1.0
2.0
3.0
4.0
5.0
Output Current (A)
E
f
f
i
ci
en
cy
4.5 V
5.0 V
5.5 V
Efficiency is tested at Vref=2.5 V
Thermal Derating Curves
VRAH-05BT50 SRAH-05BT50
Test Condition: Derating curves are tested at nominal input voltage and Vref=2.5V.
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 CONVERTER
5 V Input
Vref/2 / 5 A Output
Mechanical Outline
SRAH-05BT50
bel
Pin Connections
Pin
Function
1
Remote On/Off (option)
2 Vin
3 Ground
4 Vout
5 Vref
(option)
6 N/A
7 N/A
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