OKL2-T/3-W12P-C 查看數據表（PDF） - Murata Power Solutions
零件编号
产品描述 (功能)
生产厂家
OKL2-T/3-W12P-C Datasheet PDF : 17 Pages
| |||
TECHNICAL NOTES
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 is recommended to have a ±0.5% accuracy (or better) with low
temperature coefficient, ±100 ppm/°C 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 capacitors to Trim.
OKL-T/3-W12
Output Voltage
5.0 V.
3.3 V.
2.5 V.
2.0 V.
1.8 V.
1.5 V.
1.2 V.
1.0 V.
0.591 V.
Calculated Rtrim (KΩ)
1.34
2.18
3.1
4.19
4.88
6.50
9.70
14.45
∞ (open)
Resistor Trim Equation, OKL-T/3-W12 models:
RTRIM (k) = ____5_.9_1_______
VOUT – 0.591
Do not connect any additional components between the Vtrim pin and Vout
or between the Trim and Sense pins. Use only the specified connections as
recommended per this data sheet.
Input Fusing
Certain applications and/or safety agencies may require fuses at the inputs
of power conversion components. Fuses should also be used when there
is the possibility of sustained input voltage reversal which is not current-
limited. For greatest safety, we recommend a fast blow fuse installed in the
ungrounded input supply line.
The installer must observe all relevant safety standards and regulations.
For safety agency approvals, install the converter in compliance with the
end-user safety standard.
Input Under-Voltage Shutdown and Start-Up Threshold
Under normal start-up conditions, converters will not begin to regulate
properly until the ramping-up input voltage exceeds and remains at the
Start-Up Threshold Voltage (see Specifications). Once operating, convert-
ers will not turn off until the input voltage drops below the Under-Voltage
Shutdown Limit. Subsequent restart will not occur until the input voltage
rises again above the Start-Up Threshold. This built-in hysteresis prevents
any unstable on/off operation at a single input voltage.
Users should be aware however of input sources near the Under-Voltage
Shutdown whose voltage decays as input current is consumed (such as
capacitor inputs), the converter shuts off and then restarts as the external
capacitor recharges. Such situations could oscillate. To prevent this, make
www.murata-ps.com/support
OKL-T/3-W12 Series
Programmable Output 3-Amp iLGA SMT PoLs
sure the operating input voltage is well above the UV Shutdown voltage AT
ALL TIMES.
Start-Up Time
Assuming that the output current is set at the rated maximum, the Vin to
Vout Start-Up Time (see Specifications) is the time interval between the
point when the ramping input voltage crosses the Start-Up Threshold and
the fully loaded regulated output voltage enters and remains within its
specified accuracy band. Actual measured times will vary with input source
impedance, external input capacitance, input voltage slew rate and final
value of the input voltage as it appears at the converter.
These converters include a soft start circuit to moderate the duty cycle
of its PWM controller at power up, thereby limiting the input inrush current.
The On/Off Remote Control interval from On command to Vout regulated
assumes that the converter already has its input voltage stabilized above
the Start-Up Threshold before the On command. The interval is measured
from the On command until the output enters and remains within its
specified accuracy band. The specification assumes that the output is fully
loaded at maximum rated current. Similar conditions apply to the On to
Vout regulated specification such as external load capacitance and soft
start circuitry.
Recommended Input Filtering
The user must assure that the input source has low AC impedance to
provide dynamic stability and that the input supply has little or no inductive
content, including long distributed wiring to a remote power supply. The
converter will operate with no additional external capacitance if these
conditions are met.
For best performance, we recommend installing a low-ESR capacitor
immediately adjacent to the converter’s input terminals. The capacitor should
be a ceramic type such as the Murata GRM32 series or a polymer type. Initial
suggested capacitor values are 10 to 22 μF, rated at twice the expected maxi-
mum input voltage. Make sure that the input terminals do not go below the
undervoltage shutdown voltage at all times. More input bulk capacitance may
be added in parallel (either electrolytic or tantalum) if needed.
Recommended Output Filtering
The converter will achieve its rated output ripple and noise with no
additional external capacitor. However, the user may install more external
output capacitance to reduce the ripple even further or for improved
dynamic response. Again, use low-ESR ceramic (Murata GRM32 series)
or polymer capacitors. Initial values of 10 to 47 μF may be tried, either
single or multiple capacitors in parallel. Mount these close to the converter.
Measure the output ripple under your load conditions.
Use only as much capacitance as required to achieve your ripple and
noise objectives. Excessive capacitance can make step load recovery slug-
gish or possibly introduce instability. Do not exceed the maximum rated
output capacitance listed in the specifications.
Input Ripple Current and Output Noise
All models in this converter series are tested and specified for input
reflected ripple current and output noise using designated external input/
output components, circuits and layout as shown in the figures below. The
Cbus and Lbus components simulate a typical DC voltage bus. Please note
that the values of Cin, Lbus and Cbus will vary according to the specific
converter model.
MDC_OKL-T/3-W12 Series.C02 Page 13 of 17
Share Link: 