MQFL-28VE-06S
6V
Output:
Current:
17A
Technical Specification
NOTE: Converters operating from separate input filters with
reverse polarity protection (such as the MQME-28-T filter) with
their outputs connected in parallel may exhibit hiccup operation
at light loads. Consult factory for details.
100,000
10,000
1,000
100
OUTPUT VOLTAGE TRIM: If desired, it is possible to increase
the MQFL converter’s output voltage above its nominal value. To
do this, use the +SENSE pin (pin 10) for this trim function instead
of for its normal remote sense function, as shown in Figure D.
In this case, a resistor connects the +SENSE pin to the –SENSE
pin (which should still be connected to the output return, either
remotely or locally). The value of the trim resistor should be chosen
according to the following equation or from Figure E:
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
Incꢂease in Vout (V)
Vnom
Rtrim = 100 x
[
Vout – Vnom – 0.025
]
where:
Figure E: Output Voltage Trim Graph
Vnom = the converter’s nominal output voltage,
Vout = the desired output voltage (greater than Vnom), and
Rtrim is in Ohms.
INPUT UNDER-VOLTAGE LOCKOUT: The MQFL converter
has an under-voltage lockout feature that ensures the converter will
be off if the input voltage is too low. This lockout only appears
when the boost-converter is not operating. The threshold of input
voltage at which the converter will turn on is higher that the thresh-
old at which it will turn off. In addition, the MQFL converter will
not respond to a state of the input voltage unless it has remained
in that state for more than about 200µs. This hysteresis and the
delay ensure proper operation when the source impedance is high
or in a noisy environment.
As the output voltage is trimmed up, it produces a greater voltage
stress on the converter’s internal components and may cause the
converter to fail to deliver the desired output voltage at the low
end of the input voltage range at the higher end of the load cur-
rent and temperature range. Please consult the factory for details.
Factory trimmed converters are available by request.
INPUT OVER-VOLTAGE SHUTDOWN: The MQFL converter
also has an over-voltage feature that ensures the converter will be
off if the input voltage is too high. It also has a hysteresis and time
delay to ensure proper operation.
1
12
+VIN
ENA 2
2
3
4
5
6
11
External bulk capacitor
RSTABILITY
IN RTN
SHARE
10
STABILITY
ENA 1
+SNS
+
28 Vdc
RTRIM
MQFL
9
-SNS
8
open
means
on
SYNC OUT
SYNC IN
OUT RTN
Load
7
+VOUT
CSTABILITY
+
Figure D: Typical connection for output voltage trimming.
Product # MQFL-28VE-06S
Phone 1-888-567-9596
www.synqor.com
Doc.# 005-0005209 Rev. 1
04/22/09
Page 13
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