PQ60150EKXXX Datasheet, PDF (12/15 Pages) SynQor Worldwide Headquarters – Thermal shutdown protects converter from abnormal environmental conditions

Technical Specification
Input: 35-75V
Output: 15V
Current: 3.3A
Part No.: PQ60150EKx03
OUTPUT VOLTAGE TRIM (Pin 6): The TRIM input permits the
user to adjust the output voltage across the sense leads up or
down according to the trim range specifications.
To decrease the output voltage, the user should connect a
resistor between Pin 6 and Pin 5 (SENSE(-) input). For a desired
decrease of the nominal output voltage, the value of the resistor
should be
( ) ^Rtrim-down ⁼
511
∆%
- 10.22 (kW)
where
∆% =
Vnominal – Vdesired
Vnominal
x 100%
To increase the output voltage, the user should connect a
resistor between Pin 6 and Pin 7 (SENSE(+) input). For a desired
increase of the nominal output voltage, the value of the resistor
should be
( ) ^{Rtrim-up = 5.11VOUT(100+∆%) _ 511 _ 10.22 (kW)}
1.225∆%
∆%
where
V_OUT = Nominal Output Voltage
Figure C graphs the relationship between the trim resistor value
and Rtrim-up and Rtrim-down, showing the total range the
output voltage can be trimmed up or down.
Note: the TRIM feature does not affect the voltage at which the
output over-voltage protection circuit is triggered. Trimming the
output voltage too high may cause the over-voltage protection
circuit to engage, particularly during transients.
It is not necessary for the user to add capacitance at the Trim
pin. The node is internally bypassed to eliminate noise.
100,000
10,000
1,000
100
10
Total DC Variation of Vout: For the converter to meet its
full specifications, the maximum variation of the DC value of
Vout, due to both trimming and remote load voltage drops,
should not be greater than that specified for the output
voltage trim range.
PROTECTION FEATURES
Input Under-Voltage Lockout: The converter is designed
to turn off when the input voltage is too low, helping avoid an
input system instability problem, described in more detail in the
application note titled “Input System Instability”. The lockout
circuitry is a comparator with DC hysteresis. When the input
voltage is rising, it must exceed the typical Turn-On Voltage
Threshold value (listed on the specification page) before the
converter will turn on. Once the converter is on, the input
voltage must fall below the typical Turn-Off Voltage Threshold
value before the converter will turn off.
Output Current Limit: Once the output current reaches the
current-limit point, the converter is in the cycle-by-cycle current
limit mode for a short time that the typical value is 210µs. If the
over current no longer exists during this short time, the converter
resumes the normal condition. If the over current still persists
after this short time, the converter enters a “hiccup mode” where
it repeatedly turns on and off at a 5 Hz (nominal) frequency until
the over current condition is removed. The dual advantages of
this design are that a short term overload will not cause a hiccup
mode restart and it prevents excessive heating of the converter
or the load board in extended over current condition.
Output Over-Voltage Limit: If the voltage across the output
pins exceeds the Output Over-Voltage Protection threshold, the
converter will immediately stop switching. This prevents damage
to the load circuit due to 1) excessive series resistance in output
current path from converter output pins to sense point, 2) a
release of a short-circuit condition, or 3) a release of a current
limit condition. Load capacitance determines exactly how high
the output voltage will rise in response to these conditions. After
200 ms the converter will automatically restart.
Over-Temperature Shutdown: A temperature sensor on
the converter senses the average temperature of the module.
The thermal shutdown circuit is designed to turn the converter
off when the temperature at the sensed location reaches the
Over-Temperature Shutdown value. It will allow the converter
to turn on again when the temperature of the sensed location
falls by the amount of the Over-Temperature Shutdown Restart
Hysteresis value.
1
0
2
4
6
8
10
% increase Vout % decrease Vout
Figure C: Trim^FG^igr^uap^rh^e f^Cor^:1^T5V^ro^imut m^Go^rd^au^ple^{h for 1.8Vout module}
Product # PQ60150EKx03
Phone [phone]
www.synqor.com
Doc.# 005-0005265 Rev. A
08/20/09
Page 12