Datasheet

UHE Series
Isolated, High Efficiency, 1.6" × 2"
2-10 Amp, 12-30 Watt DC/DC Converters
MDC_UHE_12-30W Series.D03 Page 14 of 16
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Features and Options
On/Off Control
The input-side, remote On/Off Control function (pin 4) can be ordered to operate
with either logic type:
Standard models are equipped with Positive-logic (no part-number suffix) and
these devices are enabled when pin 4 is left open (or is pulled high, applying to
+15V with respect to –Input, pin 2) as per Figure 4. Positive-logic devices are
disabled when pin 4 is pulled low (0 to 0.8V with respect to –Input).
Optional Negative-logic devices ("N" suffix) are off when pin 4 is left open
(or pulled high, applying +3.5V to +15V), and on when pin 4 is pulled low (0 to
0.8V) with respect to –VIN as shown in Figure 5.
Dynamic control of the remote on/off function is best accomplished with a
mechanical relay or an open-collector/open-drain drive circuit (optically iso-
lated if appropriate). The drive circuit should be able to sink appropriate current
(see Performance Specs) when activated and withstand appropriate voltage
when deactivated. Applying an external voltage to pin 4 when no input power is
applied to the converter can cause permanent damage to the converter.
Trimming Output Voltage
UHE converters have a trim capability (pin 9) that allows users to adjust the
output voltages ±5% of VOUT (±10% for T models). Adjustments to the output
voltages can be accomplished via a trim pot (Figure 6) or a single fixed resistor
as shown in Figures 7 and 8. A single fixed resistor can increase or decrease
the output voltage depending on its connection. The resistor should be located
close to the converter and have a TCR less than 100ppm/°C to minimize
sensitivity to changes in temperature. If the trim function is not used, leave the
trim pin floating.
A single resistor connected from the Trim (pin 9) to the +Output (pin 6), or
+Sense where applicable, will decrease the output voltage for all models with
the exception of the 1.2V models, which will increase the output voltage in this
configuration. A resistor connected from the Trim (pin 9) to the –Output (pin 7),
or –Sense where applicable, will increase the output voltage for all models with
the exception of the 1.2V models, which will decrease the output voltage in this
configuration.
Soldering Guidelines
Murata Power Solutions recommends the specifications below when installing these
converters. These specifications vary depending on the solder type. Exceeding these
specifications may cause damage to the product. Be cautious when there is high atmo-
spheric humidity. Your production environment may differ; therefore please thoroughly
review these guidelines with your process engineers.
Wave Solder Operations for through-hole mounted products (THMT)
For Sn/Ag/Cu based solders:
Maximum Preheat Temperature 115° C.
Maximum Pot Temperature 270° C.
Maximum Solder Dwell Time 7 seconds
For Sn/Pb based solders:
Maximum Preheat Temperature 105° C.
Maximum Pot Temperature 250° C.
Maximum Solder Dwell Time 6 seconds
4
2
1
+INPUT
13V CIRCUIT
5V CIRCUIT
–INPUT
ON/OFF
CONTROL
Figure 4. Driving the Positive Logic On/Off Control Pin
4
2
1
+INPUT
+V
CC
–INPUT
ON/OFF
CONTROL
Figure 5. Driving the Negative Logic On/Off Control Pin
LOAD
+OUTPUT
–INPUT
+INPUT
ON/OFF
CONTROL
TRIM
+SENSE
–OUTPUT
–SENSE
7
8
2
1
9
6
5
4
20kΩ
5-22
TURNS
Figure 6. Trim Connections Using A Trimpot
LOAD
R1
+OUTPUT
–INPUT
+INPUT
ON/OFF
CONTROL
TRIM
+SENSE
–OUTPUT
–SENSE
7
8
2
1
9
6
5
4
Figure 7. Trim Connections To Decrease Output Voltages Using a Fixed Resistor
(for all models except 1.2V models which will increase VOUT)
LOAD
R2
+OUTPUT
–INPUT
+INPUT
ON/OFF
CONTROL
TRIM
+SENSE
–OUTPUT
–SENSE
7
8
2
1
9
6
5
4
Figure 8. Trim Connections To Increase Output Voltages
(for all models except 1.2V models which will decrease VOUT)