APPLICATION NOTES
Output Over Voltage Protection:
Safety:
The output voltage is constantly monitored by the
microprocessor. If the output voltage exceeds the
over-voltage specification, the microprocessor will
latch the converter off. To turn the converter on
requires either cycling on the ON/OFF pin or power to
the converter. This advanced feature prevents the
converter from damaging the load if there is a con-
verter failure or application error. If non-latching is
required, consult factory.
An external input fuse must always be used to meet
these safety requirements.
Trim:
To trim the output voltage higher, connect the
required trim resistor from the Trim pin to the
+Sense pin. To trim the output voltage lower, con-
nect the required trim resistor from the Trim pin to
the –Sense pin. See diagram below.
Thermal Shutdown:
The baseplate temperature is monitored with a PTC
thermal sensor. If the maximum rated temperature is
exceeded, the converter behaves as described in the
specifications (latch or auto-restart). If the converter
is the latching type, it is re-enabled by either cycling
the power or enable ON/OFF. If the converter is the
non-latching type, it will restart when the temperature
decreases below the trip point and no less than 2
seconds, whichever occurs later.
Trim-down
1000
100
10
0
0
2
3
4
5
6
7
8
9
10
1
Control Options:
Decrease in Output Voltage (%)
As the behavior of the circuit is determined by
firmware in the microcontroller, specific customer
requirements such as:
• latching thermal protection
• custom valid input voltage range
100
RTRIM-DOWN
=
– 2 kΩ
{∆% }
• controlled delay from initiating an ON/OFF signal
for power sequencing can be accomplished with no
change to hardware.
52V Trim-up
10000
The standard behavior was chosen based on system
design experience but we understand that customers
often have their own requirements.
1000
Please consult Galaxy Power for your special needs.
Remote Sense:
The output voltage is regulated at the point where
the sense pins connect to the power output pins. Total
sense compensation should not exceed 1V.
100
0
2
3
4
5
6
7
8
9
10
1
Increase in Output Voltage (%)
Vo (100+∆%) (100+2∆%)
External Output Trimming
RTRIM-UP
=
–
kΩ
{
}
1.225∆%
∆%
6
7
8
6
7
8
GHBW53V08A – 4
WWW.GALAXYPWR.COM
Part No. 02-GHB-03 Rev. 0.94– 031605
Galaxy Power Inc. 155 Flanders Road Westborough, MA 01581 Telephone: 508-870-9775 Fax: 508-870-9796 e-mail: info@galaxypwr.com
GALAXY [ GALAXY POWER, INC. ]
