OKR-T6 Datasheet, PDF (5/11 Pages) Murata Power Solutions Inc. – Adjustable Output 6-Amp SIP-mount DC/DC Converters

OKR-T/6 Series
Adjustable Output 6-Amp SIP-mount DC/DC Converters
Notes
(1) All specifications are typical unless noted. General conditions for Specifications are +25
deg.C, Vin=nominal, Vout=nominal (no trim installed), full rated load. Adequate airflow
must be supplied for extended testing under power.
All models are tested and specified with external 1μF and 10 μF paralleled ceramic/
tantalum output capacitors and a 22 μF external input capacitor. All capacitors are low
ESR types. Caps are layout dependent These capacitors are necessary to accommodate
our test equipment and may not be required in your applications. All models are stable
and regulate within spec under no-load conditions.
(2) Input Back Ripple Current is tested and specified over a 5 Hz to 20 MHz bandwidth. Input
filtering is Cin=2 x 100 μF, 100V tantalum, Cbus=1000 μF, 100V electrolytic, Lbus=1 μH.
All caps are low ESR types.
(3) Note that Maximum Power Derating curves indicate an average current at nominal input
voltage. At higher temperatures and/or lower airflow, the DC/DC converter will tolerate
brief full current outputs if the total RMS current over time does not exceed the Derating
curve. All Derating curves are presented at sea level altitude. Be aware of reduced power
dissipation with increasing altitude.
(4a) Mean Time Before Failure is calculated using the Telcordia (Belcore) SR-332 Method 1,
Case 3, ground fixed conditions, Tpcboard=+25 ˚C, full output load, natural air convec-
tion.
(4b) Mean Time Before Failure is calculated using the MIL-HDBK-217N2 method, ground
benign, +25ºC., full output load, natural convection.
(5) The On/Off Control is normally controlled by a switch or open collector or open drain tran-
sistor. But it may also be driven with external logic or by applying appropriate external
voltages which are referenced to Input Common.
(6) Short circuit shutdown begins when the output voltage degrades approximately 2% from
the selected setting.
(7) The outputs are not intended to sink appreciable reverse current.
(8) “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 damag-
ing the converter. Once the fault is removed, the converter immediately recovers normal
operation.
(9) Input Fusing: If reverse polarity is accidentally applied to the input, to ensure reverse
input protection with full output load, always connect an external input fast-blow fuse
in series with the +Vin input. Use approximately twice the full input current rating with
nominal input voltage.
(10) Regulation specifications describe the deviation as the line input voltage or output load
current is varied from a nominal midpoint value to either extreme.
(11) CAUTION: Since the converter is mounted on the end by its pins, do not subject it to high
vibration, shock or acceleration.
(12) Output current limit and short circuit protection is non-latching. When the overcurrent
fault is removed, the converter will immediately recover.
(13) Do not exceed maximum power specifications when adjusting the output trim. All pub-
lished specifications are listed at rated nominal output current using published Derating
curves. The maximum power specifications indicate brief operation before overcurrent
shutdown occurs. Note particularly that current must be limited at higher output voltage
in order to comply with maximum power requirements.
(14) At zero output current, the output may contain low frequency components which exceed
the ripple specification. The output may be operated indefinitely with no load.
(15) The input and output are not isolated. They share a single COMMON power and signal
return.
(16) Vin must be 2V or higher than Vout for 3.3 to 6V outputs: Vin >= (2V + Vout)
Trim Connections
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 film type, ±0.5% accuracy or
better with low temperature coefficient, ±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
specified 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.
OKR-T/6-W12
Output Voltage
6 V.
5 V.
3.3 V.
2.5 V.
1.8 V.
1.5 V.
1.2 V.
1.0 V.
0.591 V.
Calculated Rtrim (Ω)
218.5
268
436
619
978
1300
1940
2890
∞ (open)
+VOUT
Trim
RTRIM
Ground
RTRIM (kΩ) = ^1.182
VOUT − 0.591
RLOAD
Resistor Trim Equation, OKR-T/6-W12 models:
RTRIM (k:) = ^{____1_.1_8_2______}
(VOUT – 0.591)
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25 Feb 2010 MDC_OKR-T/6-W12 Series.A03 Page 5 of 11