OKI-T/36W-W40N-C Murata Power Solutions Inc, OKI-T/36W-W40N-C Datasheet - Page 7

• Manufacturer Part Number: OKI-T/36W-W40N-C
• Description: DC-DC CONVERTER, 15.5V, 36W
• Manufacturer: Murata Power Solutions Inc

Specifications of OKI-T/36W-W40N-C

• Dc / Dc Converter O/p Type: Selectable Voltage
• No. Of Outputs: 1
• Input Voltage: 19VDC To 40VDC
• Power Rating: 36W
• Output Voltage: 15.5V
• Output Current: 3A
• Approval Bodies: EN, IEC, UL
• Supply Voltage: 24V
• Product: Non-Isolated / POL
• Output Power: 36 W
• Input Voltage (nominal): 24 V
• Output Voltage (channel 1): 5.021 V to 15.5 V
• Output Current (channel 1): 3 A
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Minimum Output Loading Requirements
All models regulate within specifi cation and are stable under no load to full
load conditions. Operation under no load might however slightly increase
output ripple and noise.
Thermal Shutdown
To prevent many over temperature problems and damage, these converters
include thermal shutdown circuitry. If environmental conditions cause the
temperature of the DC/DC’s to rise above the Operating Temperature Range
up to the shutdown temperature, an on-board electronic temperature sensor
will power down the unit. When the temperature decreases below the turn-on
threshold, the converter will automatically restart. There is a small amount of
hysteresis to prevent rapid on/off cycling.
shut down suddenly without warning. Be sure to thoroughly test your applica-
tion to avoid unplanned thermal shutdown.
Temperature Derating Curves
The graphs in the next section illustrate typical operation under a variety of
conditions. The Derating curves show the maximum continuous ambient air
temperature and decreasing maximum output current which is acceptable
under increasing forced airfl ow measured in Linear Feet per Minute (“LFM”).
Note that these are AVERAGE measurements. The converter will accept brief
increases in current or reduced airfl ow as long as the average is not exceeded.
itself which is obviously running at higher temperature than the outside air.
Also note that “natural convection” is defi ned as very fl ow rates which are not
using fan-forced airfl ow. Depending on the application, “natural convection” is
usually about 30-65 LFM but is not equal to still air (0 LFM).
cycle wind tunnel with calibrated airfl ow. We use both thermocouples and an
infrared camera system to observe thermal performance. As a practical matter,
it is quite diffi cult to insert an anemometer to precisely measure airfl ow in
most applications. Sometimes it is possible to estimate the effective airfl ow if
you thoroughly understand the enclosure geometry, entry/exit orifi ce areas and
the fan fl owrate specifi cations.
CAUTION: If you operate too close to the thermal limits, the converter may
Note that the temperatures are of the ambient airfl ow, not the converter
Murata Power Solutions makes Characterization measurements in a closed
+OUTPUT
-OUTPUT
Figure 3. Measuring Output Ripple and Noise (PARD)
C1 = 0.1μF CERAMIC
C2 = 10μF TANTALUM
LOAD 2-3 INCHES (51-76mm) FROM MODULE
C1
COPPER STRIP
COPPER STRIP
C2
SCOPE
www.murata-ps.com
R
LOAD
Selectable Output 36-Watt DOSA-SMT DC/DC Converters
an unplanned Over Temperature shut down. Also, these graphs are all collected
near Sea Level altitude. Be sure to reduce the derating for higher altitude.
Output Fusing
The converter is extensively protected against current, voltage and temperature
extremes. However your output application circuit may need additional protec-
tion. In the extremely unlikely event of output circuit failure, excessive voltage
could be applied to your circuit. Consider using an appropriate fuse in series
with the output.
Output Current Limiting
Current limiting inception is defi ned as the point at which full power falls below
the rated tolerance. See the Performance/Functional Specifi cations. Note par-
ticularly that the output current may briefl y rise above its rated value in normal
operation as long as the average output power is not exceeded. This enhances
reliability and continued operation of your application. If the output current is
too high, the converter will enter the short circuit condition.
Output Short Circuit Condition
When a converter is in current-limit mode, the output voltage will drop as the
output current demand increases. If the output voltage drops too low (approxi-
mately 98% of nominal output voltage for most models), the PWM bias voltage
will also drop, thereby shutting down the PWM controller. Following a time-out
period, the PWM will restart, causing the output voltage to begin ramping up to
its appropriate value. If the short-circuit condition persists, another shutdown
cycle will initiate. This rapid on/off cycling is called “hiccup mode”. The hiccup
cycling reduces the average output current, thereby preventing excessive inter-
nal temperatures and/or component damage. A short circuit can be tolerated
indefi nitely.
because you do not have to power down the converter to make it restart. The
system will automatically restore operation as soon as the short circuit condi-
tion is removed.
Remote On/Off Control
On the input side, a remote On/Off Control can be ordered with either polarity.
Please refer to the Connection Diagram on page 1 for On/Off connections.
pulled high to +Vin with respect to –Vin. Positive-polarity devices are disabled
when the On/Off is grounded or brought to within a low voltage (see Specifi ca-
tions) with respect to –Vin.
brought to within a low voltage (see Specifi cations) with respect to –Vin. The
device is off (disabled) when the On/Off is pulled high (see Specifi cations) with
respect to –Vin.
fi ed signal current when brought low and withstand the specifi ed voltage
when brought high. Be aware too that there is a fi nite time in milliseconds
(see Specifi cations) between the time of On/Off Control activation and stable,
regulated output. This time will vary slightly with output load type and current
and input conditions.
CAUTION: If you exceed these Derating guidelines, the converter may have
The “hiccup” system differs from older latching short circuit systems
Positive-polarity models are enabled when the On/Off pin is left open or is
Negative-polarity devices are on (enabled) when the On/Off is left open or
Dynamic control of the On/Off function should be able to sink the speci-
OKI-T/36W-W40 Series
09 Feb 2011 MDC_OKI-T/36W-W40.A01 Page 7 of 12
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