GS-R400 FAMILY
ELECTRICAL CHARACTERISTICS
(T
A
= 25°C unless otherwise specified)
Symbol
∆V
o/∆T
Io
IoL
Iisc
fs
SVR
Vr
tss
Vinhl
Vinhh
Iinhh
tcb
Vrh*
Vrl*
trd*
Vcth
∆V
o
Rth
Parameter
Temperature Stability
Output Current
Current Limit
Average Input Current
Switching Frequency
Supply Voltage Rejection
Ripple Voltage
Soft Start Time
Low Inhibit Voltage
High Inhibit Voltage
High Inhibit Input Current
Crow-bar Delay Time
Reset High Level
Reset Low Level
Reset Delay Time
Crowbar Intervention Threshold
Total Remote
Sense Compensation
Thermal Resistance
Case to ambient
5
Irl = 5mA
Irl = 10mA
100
Vo
•1.25
500
Vinh = 5V
5
5
0.2
0.4
2
Test Conditions
Vi = Vo+8V Io = 1A
Vi = Vo+8V
Vi = Vo+8V
Vi = 46V Output Shorted
Io = 1A
fo = 100Hz Io =1A
Io = 2A
Vi = Vo+8V
0.2
5
0.1
100
4/12
25/150
10/35
0.8
5.5
500
Min
Typ
0.2/1.6
4
8
0.2
Max
Unit
mv/°C
A
A
A
KHz
mV/V
mVpp
ms
V
V
µA
µs
V
V
ms
V
mV
°C/W
* GS-R405S only
USER NOTES
Input Voltage
The recommended operating maximum DC input
voltage is 46V inclusive of the ripple voltage.
Remote Sensing
The remote voltage sense compensation range is
for a total drop of 500mV equally shared between
the load connecting wires. It is a good practice to
shield the sensing wires to avoid oscillation.
Each sense input must be connected to its compan-
ion output power pin when the remote sense capa-
bility is not used (see fig. 1).
Case Grounding
The module case is isolated from the electrical
circuit of the switching regulator. It can be grounded
using the 4 corner pins.
The PCB area below the module can be used as an
effective sixth side shield against EMI.
Thermal Characteristics
The case-to-ambient thermal resistance of all the
GS-R400 modules is about 5°C/W. This produces
a 50°C temperature increase of the module surface
for 10W of internal power dissipation.
Depending on the ambient temperature and/or on
the power dissipation, an additional heatsink or
forced ventilation may be required.
Input Impedance
The module has an internal capacitor connected
between the input pins in order to assure PWM
stability. This capacitor cannot handle large values
of high frequency ripple current and it can be per-
manently damaged if the primary energy source
impedance is not adequate. The use of an external
low ESR, high ripple current capacitor located as
close the module as possible is recommended.
Suitable capacitors should have a RMS current
capability of 2.5A
RMS
with a working voltage of 50
V
DC
and an ESR of 0,1Ω at 100 kHz. When space
3/5
SST [ SILICON STORAGE TECHNOLOGY, INC ]
