35-75 V
5.0 V
Input:
Output:
Current:
Package:
30 A
Quarter-brick
Technical Specification
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.
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.
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
PROTECTION FEATURES
511
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 applica-
tion 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.
R
=
- 10.22 (kW)
trim-down
( D%)
where
Vnominal – Vdesired
Vnominal
=
x 100%
D%
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
Output Current Limit: The maximum current limit remains
constant as the output voltage drops. However, once the imped-
ance of the short across the output is small enough to make the
output voltage drop below the specified Output DC Current-Limit
Shutdown Voltage, the converter turns off.
5.11VOUT(100+D%)
1.225D%
511
_
_
R
=
trim-up
where
(kW)
10.22
)
(
D%
V
= Nominal Output Voltage
OUT
The converter then enters a “hiccup mode” where it repeatedly
turns on and off at a 5 Hz (nominal) frequency with a 5% duty
cycle until the short circuit condition is removed. This prevents
excessive heating of the converter or the load board.
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.
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 condi-
tion. Load capacitance determines exactly how high the output
voltage will rise in response to these conditions. After 200 ms the
converter will automatically restart.
100,000
10,000
1,000
100
Over-Temperature Shutdown: A temperature sensor on the
converter senses the average temperature of the module. The ther-
mal 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.
10
0
2
4
6
8
10
12
14
16
18
20
% increase Vout
% decrease Vout
Figure C: Trim Graph for 5.0Vout module
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.
Product # PQ60050QTA30
Phone 1-888-567-9596
www.synqor.com
Doc.# 005-2QT650C Rev. E
05/20/09
Page 10
SYNQOR [ SYNQOR WORLDWIDE HEADQUARTERS ]
