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 V-5.5 V Input
0.9 V-3.3 V/3 A Output
Non-Isolated
Remote
On/Off
High
Efficiency
Input Under Voltage Lockout
Fixed Frequency (300 kHz)
OCP/SCP
Low
Cost
Wide
Range
Trim
Description
The Bel x7AH-03F1A0 module is a non-isolated, step down dc/dc converter that operates from 3.0 V to 5.5 V
source. This converter is available in a range of output voltages from 0.9 V to 3.3 V. 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 efficiency of 3.3 V module is typically 92% at 5 V input 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 V - 3.3 V 3.0 V - 5.5 V
3 A
10 W
92%
S7AH-03F1A0
V7AH-03F1A0
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
-40
C
-
125
C
Input Specifications
Parameter
Min
Typ
Max
Notes
Input Voltage
V
O
=3.3 V
V
O
=2.5 V
V
O
=0.9 V-1.8 V
4.5 V
3.6 V
3.0 V
-
-
-
5.5 V
5.5 V
5.5 V
Input Current (no load)
-
-
70 mA
Input Current (full load)
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
Vo=0.9 V
-
-
-
-
-
-
-
-
-
-
-
-
2.5 A
2.4 A
2.2 A
1.9 A
1.6 A
1.3 A
Remote Off Input Current
-
5 mA
10 mA
Input Reflected Ripple Current (pk-pk)
-
75 mA
-
Input Reflected Ripple Current (rms)
-
25 mA
-
Tested with simulated source
impedance of 500 nH, 5 Hz to 20 MHz
and two 270 uF/16 V Oscon caps with
ESR=0.018 ohm max at 100 kHz
x7AH-03F1A0
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 V-5.5 V Input
0.9 V-3.3 V/3 A Output
Input Specifications (continued)
Parameter
Min
Typ
Max
Notes
I
2
t Inrush Current Transient
-
0.004 A
2
s
0.008 A
2
s
Turn on Voltage Threshold
-
-
2.9 V
Turn off Voltage Threshold
2.2 V
2.4 V
-
Only for 0.9 V-1.8 V output modules.
Note:
All specifications are typical at nominal input (5 V), full load at 25
C
unless otherwise stated.
Output Specifications
Parameter
Min
Typ
Max
Notes
Output Voltage Set Point
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
=0.9 V
3.217 V
2.437 V
1.755 V
1.462 V
1.170 V
0.877 V
3.3 V
2.5 V
1.8 V
1.5 V
1.2 V
0.9 V
3.383 V
2.563 V
1.845 V
1.538 V
1.230 V
0.923 V
Test conditions:
Vin=5 V, Io=50% full
load
Line Regulation
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
=0.9 V
-
-
-
-
-
-
10 mV
8 mV
6 mV
5 mV
4 mV
3 mV
20 mV
16 mV
12 mV
10 mV
8 mV
6 mV
Load Regulation
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
=0.9 V
-
-
-
-
-
-
17 mV
13 mV
9 mV
8mV
6 mV
5 mV
33 mV
25 mV
18 mV
15 mV
12 mV
9 mV
Regulation Over Temperature(-40
C to +85 C)
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
=0.9 V
-
-
-
-
-
-
72 mV
54 mV
39 mV
32 mV
26 mV
19 mV
97 mV
72 mV
52 mV
43 mV
40 mV
40 mV
Output Current
0 A
-
3 A
Current Limit Threshold
5 A
-
12 A
Short Circuit Surge Transient
-
0.022 A
2
s 0.044
A
2
s
Ripple and Noise (rms)
V
O
=1.2 V-3.3 V
V
O
=0.9 V
-
-
15 mV
10 mV
25 mV
20 mV
Ripple and Noise (pk-pk)
V
O
=1.2 V-3.3 V
V
O
=0.9 V
-
-
50 mV
40 mV
70 mV
60 mV
Test condition: 0-20 MHz
BW
Turn on Time
-
7 mS
12 mS
Overshoot at Turn on
-
0%
3%
Output Capacitance
0 uF
-
1200 uF
Transient Response
Overshoot
-
150 mV
200 mV
50% ~ 100%
Max Load
Settling Time
-
20 uS
40 uS
Overshoot
-
150 mV
200 mV
100% ~ 50%
Max Load
Settling Time
All
-
20 uS
40 uS
Test conditions:
di/dt = 0.5 A/uS; Vin =
5 V
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 V-5.5 V Input
0.9 V-3.3 V/3 A Output
General Specifications
Parameter
Min
Typ
Max
Notes
Efficiency
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
Vo=0.9 V
88%
86%
83%
80%
77%
75%
92%
90%
87%
84%
81%
79%
-
-
-
-
-
-
Measured at Vin=5 V, full load and
Ta=25
C
Switching Frequency
250 kHz
300 kHz
360 kHz
Output Trim Range (wide trim)
-
-
403% Vo
Vo=0.9 V
Output Trim Range (narrow trim)
V
O
=1.2 V-3.3 V
V
O
=0.9 V
90% Vo
-
-
-
110% Vo
110% Vo
MTBF
7,800,000 hours
Calculated Per Bell Core TR-332 (Vin=
5 V; Vo=3.3 V; I
O
= 2.4 A; T
a
= 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
-
Control Specifications
Parameter
Min
Typ
Max
Notes
Remote On/Off
Signal Low (Unit Off)
-0.3 V
-
0.8 V
Signal High (Unit On)
2.8 V
-
6 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 (Vo) are shown below. 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.
1
712
.
3
-
-
=
-
o
adj
up
trim
V
V
R
Note:
Output voltage Vo=0.902V when Ttrim-up is not connected.
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 V-5.5 V Input
0.9 V-3.3 V/3 A Output
Efficiency Data
MODULE 3.3V
75.0%
80.0%
85.0%
90.0%
95.0%
100.0%
0.30
0.75
1.50
2.25
3.00
OUTPUT CURRENT (A)
E
F
F
I
CI
E
N
CY
4.5V
5.0V
5.5V
MODULE 1.8V
65.0%
70.0%
75.0%
80.0%
85.0%
90.0%
95.0%
0.30
0.75
1.50
2.25
3.00
OUTPUT CURRENT (A)
EFF
I
C
I
EN
C
Y
3.0V
3.3V
5.0V
5.5V
MODULE 0.9V
60.0%
65.0%
70.0%
75.0%
80.0%
85.0%
90.0%
0.30
0.75
1.50
2.25
3.00
OUTPUT CURRENT (A)
E
F
F
I
CI
E
N
CY
3.0V
3.3V
5.0V
5.5V
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 CONVERTERS
3.0 V-5.5 V Input
0.9 V-3.3 V/3 A Output
Thermal Derating Curve
x7AH-03F1A0
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