Datasheet

Specifi cation Notes, Cont.:
(5) The On/Off Control Input should use either a switch or an open collector/open drain transistor referenced
to -Input Common. A logic gate may also be used by applying appropriate external voltages which do not
exceed +Vin.
(6) Short circuit shutdown begins when the output voltage degrades approximately 2% from the selected
setting.
(7) Deleted.
(8) Output noise may be further reduced by adding an external fi lter. At zero output current, the output may
contain low frequency components which exceed the ripple specifi cation. The output may be operated
indefi nitely with no load.
(9) All models are fully operational and meet published specifi cations, including “cold start” at –40˚ C.
(10) Regulation specifi cations describe the deviation as the line input voltage or output load current is varied
from a nominal midpoint value to either extreme.
(11) Other input or output voltage ranges will be reviewed under scheduled quantity special order.
(12) Maximum PC board temperature is measured with the sensor in the center of the converter.
(13) Do not exceed maximum power specifi cations when adjusting the output trim.
(14) The maximum output capacitive loads depend on the the Equivalent Series Resistance (ESR) of the external
output capacitor and, to a lesser extent, the distance and series impedance to the load. Larger caps will
reduce output noise but may change the transient response. Newer ceramic caps with very low ESR may
require lower capacitor values to avoid instability. Thoroughly test your capacitors in the application. Please
refer to the Output Capacitive Load Application Note.
(15) Do not allow the input voltage to degrade lower than the input undervoltage shutdown voltage at all times.
Otherwise, you risk having the converter turn off. The undervoltage shutdown is not latching and will
attempt to recover when the input is brought back into normal operating range.
(16) The outputs are not intended to sink appreciable reverse current.
(17) “Hiccup” overcurrent operation repeatedly attempts to restart the converter with a brief, full-current output.
If the overcurrent condition still exists, the restart current will be removed and then tried again. This short
current pulse prevents overheating and damaging the converter. Once the fault is removed, the converter
immediately recovers normal operation.
Output Voltage Adustment
The output voltage may be adjusted over a limited range by connecting an
external trim resistor (Rtrim) between the Trim pin and Ground. The Rtrim
resistor must be a 1/10 Watt precision metal fi lm type, ±1% accuracy or
better with low temperature coeffi cient, ±100 ppm/oC. or better. Mount the
resistor close to the converter with very short leads or use a surface mount
trim resistor.
In the tables below, the calculated resistance is given. Do not exceed the
specifi ed limits of the output voltage or the converter’s maximum power
rating when applying these resistors. Also, avoid high noise at the Trim
input. However, to prevent instability, you should never connect any capaci-
tors to Trim.
Soldering Guidelines
Murata Power Solutions recommends the specifi cations below when installing these
converters. These specifi cations vary depending on the solder type. Exceeding these
specifi cations may cause damage to the product. Your production environment
may differ therefore please thoroughly review these guidelines with your process
engineers.
Recommended Lead-free Solder Refl ow Profi le
High trace = normal upper limit
Low trace - normal lower limit
0
50
100
150
200
250
0 30 60 90 120 150 180 210 240 270 300
Time (sec)
Temperature (°C)
Preheating Zone
240 sec max
Soaking Zone
120 sec max
Reflow Zone
time above
217° C
45-75 sec
Peak Temp.
235-260° C
<1.5° C/sec
Reflow Solder Operations for surface-mount products (SMT)
For Sn/Ag/Cu based solders:
Preheat Temperature Less than 1 ºC. per second
Time over Liquidus 45 to 75 seconds
Maximum Peak Temperature 260 ºC.
Cooling Rate Less than 3 ºC. per second
For Sn/Pb based solders:
Preheat Temperature Less than 1 ºC. per second
Time over Liquidus 60 to 75 seconds
Maximum Peak Temperature 235 ºC.
Cooling Rate Less than 3 ºC. per second
RTRIM () =
_____________
– 1000
V
OUT – 5.021V
10500
Output Voltage Calculated Rtrim (Ω)
15 V. 52.21
12 V. 504.5
10 V. 1108.9
9 V. 1638.9
8 V. 2524.7
7 V. 4305.7
6 V. 9725.2
5.02 V. ∞ (open)
Resistor Trim Equation:
MDC_OKI-T/36W-W40.B01 Page 5 of 11
OKI-T/36W-W40 Series
Selectable Output 36-Watt DOSA-SMT DC-DC Converters
www.murata-ps.com/support