GS300T48-5
300W DC-DC CONVERTER
June 1994
1/6
Type
V
i
V
o
I
o
GS300T48-5
38 to 60 V
5,075 V
60 A
FEATURES
Very high output power (300W)
High efficiency (80% min.)
Parallel operation with current sharing
Synchronization pin
Remote ON/OFF
Remote load voltage sense compensation
Output short-circuit protection
Output overvoltage protection
Thermal protection
Undervoltage lock-out
Minimal overshoot during load transients
500 V
DC
input to output isolation
Internal input and output filtering
Softstart
PCB or chassis mountable
SELECTION GUIDE
Type
Ordering Number
Input
Voltage (V)
Output
Voltage
(V)
Output
Current
(A)
Dimensions
L
·
W
·
H mm (inches)
GS300T48-5
GS300T48-5E
38 to 60
5.075
60
125
·
66.5
·
20
( 4.92
·
2.62
·
0.79)
The suffix E identifies the metric threading
on the planar heatsink (see fig. 1).
DESCRIPTION
The GS300T48-5 is a 300W DC-DC converters
used to generate a 5.075V isolated output with a
current of 60A from a wide range input voltage (38
to 60V).
ELECTRICAL CHARACTERISTICS (T
amb
= 25
°
C unless otherwise specified)
Symbol
Parameter
Test Conditions
Min
Typ
Max
Unit
Vi
Input Voltage
Vo = 5.075V
Io = 0 to 30A
(Operating Conditions)
38
48
60
VDC
Viuv
Input Undervoltage Lockout
Io = 0 to 60A
29
36
V
li
Average Input Current
Vi = 48V
Io = 60A
7.8
A
lipk
Inrush Transient Peak Current
Vi = 60V
Io = 60A
0.3
A
2
s
lir
Reflected Input Current
Vi = 48V
Io = 60A
BW = 5Hz to 20MHz (see fig. 2)
30
mApp
Vien
Enable Input Voltage
Vi = 38 to 60V Io = 0 to 60A
0
1.2
V
lien
Enable Input Current
Vi = 38 to 60V Io = 0 to 60A
Vien = 0V
1
mA
Viinh
Max Inhibit Voltage
Vi = 38 to 60V Io = 0 to 60A
Vien = open
8
18
V
Pi
Input Power
Vi = 38 to 60V Io = 0A (No Load)
1.5
2
W
Vo
Total Output Voltage Regulation
Vi = 38 to 60V Io = 0 to 60A
4.490
5.075
5.210
V
Vost
Short-term Output
Voltage Regulation
Vi = 38 to 60V Io = 0 to 60A
5.002
5.075
5.148
V
Vots
Total Static Output
Voltage Regulation
Vi = 38 to 60V Io = 0 to 60A
4.970
5.075
5.180
V
Vol
Output Overvoltage Limit Initiation
Vi = 38 to 60V Io = 0 to 60A
6.3
V
Vor
Output Ripple Voltage
Vi = 38 to 60V Io = 60A
BW = 0 to 20 Mhz
50
mVpp
Von
Output Noise Voltage
Vi = 38 to 60V Io = 60A
BW = 0 to 20 Mhz
100
mVpp
Vo
Total Remote Sense
Compensation
Vi = 38 to 60V
0.6
V
Vo
Peak Load Transient Response
Vi = 48V
Io = 10A
slope = 0.1A/
µ
s
100
mVp
Io
Output Current
Vi = 38 to 60V Vo = 5V
0
60
A
Iol
Overcurrent Limit Initiation
Vi = 48V
63
A
Iosc
Shortcircuit Output Current
Vi = 48V
69
A
ts
Load Transient Setting Time
Vi = 48V
Io = 10A
slope = 0.1A/
µ
s
250
µ
s
ton
Turn-on Time
Vi = 38 to 60V Io = 0 to 60A
Vien = from high to low
10
ms
Vi = 0 to 60V
Io = 0 to 60A
Vien = low
10
Vis
Isolation Voltage
500
V
fs
Switching Frequency
Vi = 38 to 60V Io = 0 to 60A
160
180
200
kHz
Efficiency
Vi = 38 to 60V Io = 60A
80
81
%
Rth
Thermal Resistance
Case to Ambient
5.2
°
C/W
Tcop
Operating Case
Temperature Range
*
0
+70
°
C
Tstg
Storage Temperature Range
40
+105
°
C
*
Thermal intervention @ T
cop
= 85
°
C
2/6
GS300T48-5
3/6
Package U. Dimensions in mm (inches)
CONNECTION DIAGRAM AND MECHANICAL DATA
Figure 1.
PIN DESCRIPTION
Pin
Function
Description
1,2
- Vin
Negative input voltage.
3,4
+ Vin
Positive input voltage. Unregulated input voltage (typically 48V) must be applied between
pin 1,2-3,4.
5
SYNC
Synchronization pin. See figures 3, 4, 5, 6. Open when not used.
6
PARALLEL
Parallel output. See figures 3, 4, 5, 6. Open when not used.
7
ON/OFF
The converter is ON (Enable) when the voltage applied to this pin with reference to pin 1,2
is lower than 1,2 V (see Vien). The converter is OFF (Inhibit) for a control voltage in the
range of 8 to 18V.
When the pin is unconnected the converter is OFF (Inhibit).
8
CASE
Case connection pin
9
+ SENSE
Senses the remote load high side. To be connected to pin 15,16,17 when remote sense is
not used.
10
- SENSE
Senses the remote load return. To be connected to pin 11,12,13,14 when remote sense is
not used. In parallel configuration, take care to connect all -SENSE pins together (see
figures 3,4,5,6).
11,12,
13,14
- OUT
-5V voltage return.
15,16,
17
+ OUT
+5V output voltage.
GS300T48-5
4/6
USER NOTES
Reflected Input Current
The reflected input current measurement (lir, see Electrical Characteristics) is performed according to the
test set-up of fig. 2.
Figure 2.
Softstart
To avoid heavy inrush current the output voltage
rise time is 10ms maximum in any condition of load.
Remote Sensing
The remote voltage sense compensation range is
for a total drop of 0.6V equally shared between the
load connecting wires.
It is a good practice to shield the sensing wires to
avoid oscillations.
See the connection diagram on figures 3, 4, 5, 6.
Remote ON/OFF
The module is controlled by the voltage applied
between the ON/OFF pin and -IN pin.
The converter is ON (Enable) when the voltage
applied is lower than 1.2 V (see Vien on Electrical
Characteristics).
The converter is OFF (Inhibit) for a control voltage
in the range of 8 to 18V (see Viinh).
When the pin is unconnected the converter is OFF.
Maximum sinking current is 1mA.
Module Protection
The module is protected against occasional and
permanent shortcircuits of the outp ut pins to
ground, as well as against output current overload.
It uses a current limiting protection circuitry, avoid-
ing latch-up problems with certain type of loads.
A latching crowbar output overvoltage protection is
activated when the output voltage exceeds the
typical value of 6.3V (see Electrical Charac-
teristics). A thermal non-latchingprotection disables
the module whenever the heatsink temperature
reaches about 85
°
C.
Parallel Operation
To increase available output regulated power, the
module features the parallel connection possibility
with equal current sharing and maximum deviation
of 10% (two modules in parallel).
See the connection diagram on figures 3, 4, 5, 6.
GS300T48-5
Figure 3.
Figure 4.
Figure 5.
Figure 6.
5/6
Thermal Characteristics
The case-to-ambient thermal resistance of the
GS300T48-5 module is 5.2
°
C/W typical. It may be
decreased, improving the convection cooling, by
mounting an external heatsink to the top of the unit
heatsink (fig. 9).
Six threaded holes, # 4-40 UNC on the standard or
# M3 on the E version, 5 mm (0,2") maximum deep,
are provided for this purpose (see fig. 1).
GS300T48-5
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