isolated dc/dc converters

ISOLATED DC/DC CONVERTERS
24 Vdc/48 Vdc Input
SRQB-20U080
8 Vdc/2.5 A Output
RoHS Compliant
Rev.C
•
High Efficiency
•
Remote On/Off
•
Isolated
•
Output Voltage Trim
•
Low Cost
•
Input Under Voltage Lockout
•
Fixed Frequency (340 kHz)
•
SCP/OCP
•
Output Over Voltage Shut Down
•
Over Temperature Protection
•
Excellent Thermal Performance
•
Positive/Negative Remote Sense
•
Basic Insulation
Description
The SRQB-20U080 is an isolated dc/dc converter that operates from a nominal 24 Vdc and 48 Vdc source. This
unit provides up to 20 W of output power from a nominal 24 Vdc and 48 Vdc input. This unit is designed to be
highly efficient and low cost. Features include remote on/off, over current protection and under voltage lockout.
The converter is provided in an industry standard quarter brick package.
Part Selection
Output
Voltage
8.0 Vdc
Input Voltage
14 Vdc - 65 Vdc
Max. Output
Current
2.5 A
Max. Output
Power
20 W
Typical
Efficiency
81%
Model Number
SRQB-20U080
Notes: 1. Add “G” suffix at the end of the model number to indicate 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
Input Voltage (continuous)
Min
-0.3 V
Typ
-
Remote On/Off (Active High)
-0.3 V
-
12 V
-
-
2000 V
Ambient Temperature
-40 °C
-
85 °C
Storage Temperature
-55 °C
-
125 °C
I/O Isolation Voltage
Max
70 V
Notes
Input Specifications
Parameter
Input Voltage
Input Current
Input Current (no load)
Remote Off Input Current
Input Reflected Ripple Current
(rms)
Input Reflected Ripple Current
(pk-pk)
2
I t Inrush Current Transient
Turn-on Input Voltage
Turn-off Input Voltage
Min
14 V
-
Typ
40 mA
3 mA
Max
65 V
2.5 A
150 mA
10 mA
Notes
-
5 mA
10 mA
-
15 mA
30 mA
With simulated source impedance of
10 uH, 5 Hz to20 MHz. And use a 100
uF/ 100 V electrolytic capacitor with
ESR=1 ohm max, at 200 kHz.
-
0.012 A s
0.024 A s
12.8 V
12.5 V
13.3 V
13.0 V
13.8 V
13.5 V
2
2
Note: All specifications are typical 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
ISOLATED DC/DC CONVERTERS
24 Vdc/48 Vdc Input
8 Vdc/2.5 A Output
Output Specifications
Parameter
Min
Typ
Max
7.84 V
8.0 V
8.16 V
Line Regulation
-
±3 mV
±10 mV
Load Regulation
-
±5 mV
±15 mV
Temperature Regulation
(-40 °C to +85 °C)
-
±30 mV
±60 mV
Ripple and Noise (rms)
-
15 mV
30 mV
Ripple and Noise (pk-pk)
-
60 mV
100 mV
0A
-
2.5 A
2.7 A
4.0 A
Output Voltage Set Point
Output Current
Current Limit Threshold
Vin=48 V, IO=50% full load
0-20 MHz BW, with a 1 µF
ceramic capacitor and a
10 uF tantalum capacitor at the
output.
5.5 A
2
2
Short Circuit Surge Transient
-
0.7 A s
1.4 A s
Turn on Time
-
10 mS
25 mS
Overshoot at Turn On
-
0%
5%
0 uF
-
330 uF
Output Capacitance
Notes
Transient Response
50% ~ 75%
Max Load
Overshoot
-
100 mV
300 mV
Settling Time
-
200 uS
400 uS
50% ~ 25%
Max Load
Overshoot
-
100 mV
300 mV
Settling Time
-
200 uS
400 uS
di/dt=0.1 A/us, Vin=48 Vdc, with
a 1 uF ceramic capacitor and a
10 uF tantalum at the output.
Note: All specifications are typical at nominal input, full load at 25°C unless noted.
General Specifications
Parameter
Min
Typ
Max
77%
81%
-
Switching Frequency
300 kHz
340 kHz
380 kHz
Isolation Capacitance
-
1500 pF
-
Remote Sense Compesation
-
-
10%
7V
-
9V
Over Temperature Protection
-
125 °C
-
Over Voltage Protection
-
9.5 V
-
Efficiency
Output Voltage Trim Range
MTBF
Notes
Measured at Vin=48 V, full load
Vin=48 V, Io=full load
Calculated Per Bell Core SR-332 (IO = 80%
IO max; Vin=48 V; Vo=8 V; Ta = 25 °C)
TBD
Dimensions
Inches (L × W × H)
Millimeters (L × W × H)
Weight
2.3 x 1.45 x 0.391
58.42 x 36.83 x 9.93
-
26 g
-
Note: All specifications are typical 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
ISOLATED DC/DC CONVERTERS
24 Vdc/48 Vdc Input
8 Vdc/2.5 A Output
Control Specifications
Parameter
Min
Typ
Max
Signal Low (Unit Off)
-0.3 V
-
0.8 V
Signal High (Unit On)
3.5 V
-
12 V
Current Sink
0 mA
-
12 mA
Notes
Remote On/Off (Active High)
The remote On/Off pin open,
Unit On.
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.
Vout
Rtrim _ down
59.2
=
− 26
Vnom − Vadj
27.5
Rtrim _ up =
− 15
Vadj − Vnom
Rtrim_down
Module
Trim
GND
Vout
Module Trim
Rtrim_up
GND
Bel Fuse Inc. 206 Van Vorst Street, Jersey City, NJ 07302 • Tel 201-432-0463 • Fax 201-432-9542 • www.belfuse.com
ISOLATED DC/DC CONVERTERS
24 Vdc/48 Vdc Input
8 Vdc/2.5 A Output
Efficiency Data
Efficiency Curve
85.0%
Efficiency
80.0%
75.0%
18V
24V
48V
65V
70.0%
65.0%
60.0%
55.0%
50.0%
0.2A
0.75A 1.25A 1.75A
Output Current(A)
2.5A
Thermal Derating Curves
Vin=24 V
Vin=48 V
Bel Fuse Inc. 206 Van Vorst Street, Jersey City, NJ 07302 • Tel 201-432-0463 • Fax 201-432-9542 • www.belfuse.com
ISOLATED DC/DC CONVERTERS
24 Vdc/48 Vdc Input
8 Vdc/2.5 A Output
Ripple and Noise Waveforms
Ripple and noise at full load, 24 Vdc input, 8 Vdc/2.5 A output
Ripple and noise at full load, 48 Vdc input, 8 Vdc/2.5 A output
Note: Ripple and noise at full load, with a 1uF ceramic capacitor and a 10 uF tantalum capacitor at output,
and 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
ISOLATED DC/DC CONVERTERS
24 Vdc/48 Vdc Input
8 Vdc/2.5 A Output
Transient Response Waveforms
Vout= 8 V 50%-75% Load Transients at Vin=24 V
Vout= 8 V 50%-75% Load Transients at Vin=48 V
Vout= 8 V 75%-50% Load Transients at Vin=24 V
Vout= 8 V 75%-50% Load Transients at Vin=48 V
Note: Load Transients at di/dt=0.1 A/us, Vin=48 Vdc, with a 1 uF ceramic capacitor and a 10 uF tantalum 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
ISOLATED DC/DC CONVERTERS
24 Vdc/48 Vdc Input
8 Vdc/2.5 A Output
Mechanical Outline
Pin Connections
Pin
Function
Pin Size
1
Vin+
0.079’’
2
On/Off
0.079’’
3
Vin-
0.079’’
4
Vo-
0.10’’
5
Sense-
0.079’’
6
Trim
0.079’’
7
Sense+
0.079’’
8
Vo+
0.10’’
RoHS Compliance
Complies with the European Directive 2002/95/EC, calling for the elimination of lead and
other hazardous substances from electronic products.
©2007 Bel Fuse Inc. Specifications subject to change without notice. 010907
CORPORATE
FAR EAST
EUROPE
Bel Fuse Inc.
206 Van Vorst Street
Jersey City, NJ 07302
Tel 201-432-0463
Fax 201-432-9542
www.belfuse.com
Bel Fuse Ltd.
8F/ 8 Luk Hop Street
San Po Kong
Kowloon, Hong Kong
Tel 852-2328-5515
Fax 852-2352-3706
www.belfuse.com
Bel Fuse Europe Ltd.
Preston Technology Management Centre
Marsh Lane, Suite G7, Preston
Lancashire, PR1 8UD, U.K.
Tel 44-1772-556601
Fax 44-1772-888366
www.belfuse.com