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Teilenummer | OKY-T-5-D12N-C |
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Beschreibung | Adjustable Output 3 and 5-Amp DOSA-SMT DC/DC Converters | |
Hersteller | Murata | |
Logo | ||
Gesamt 21 Seiten www.murata-ps.com
OKY-T/3,T/5-D12 Series
Adjustable Output 3 and 5-Amp DOSA-SMT DC/DC Converters
Typical unit
PRODUCT OVERVIEW
The OKY-T/3 and -T/5 series are miniature
non-isolated Point-of-Load (POL) DC/DC power
converters for embedded applications. The module
is fully compatible with Distributed-power Open
Standards Alliance (DOSA) industry-standard
specifications (www.dosapower.com). Applications
include powering CPU’s, datacom/telecom systems,
programmable logic and mixed voltage systems.
The wide input range is 8.3 to 14 Volts DC. Two
maximum output currents are offered, 3 Amps (T/3
models) or 5 Amps (T/5 models). Based on fixed-
frequency synchronous buck converter switching
topology, the high power conversion efficient Point
of Load (POL) module features programmable
output voltage and On/Off control. These converters
also include under voltage lock out (UVLO), output
short circuit protection, over-current and over
temperature protections.
These units are designed to meet all standard
UL/EN/IEC 60950-1 safety and FCC EMI/RFI
emissions certifications and RoHS-6 hazardous
substance compliance.
FEATURES
■ Non-isolated SMT POL DC/DC power module
■ 8.3-14Vdc input voltage range
■ Programmable output voltage from 0.7525-5.5Vdc
■ 3 Amp (T/3) or 5 Amp (T/5) output current models
■ Drives 1000 μF ceramic capacitive loads
■ High power conversion efficiency 93% at 3.3 Vout
■ Outstanding thermal derating performance
■ Over temperature and over current protection
■ On/Off control
■ UL/EN/IEC 60950-1 safety
■ Industry-standard (DOSA) surface-mount package
■ RoHS-6 hazardous substance compliance
Contents
Description, Connection Diagram, Photograph
Ordering Guide, Model Numbering
Mechanical Specifications, Input/Output Pinout
Detailed Electrical Specifications
Output Voltage Adjustment, Soldering Guidelines
Technical Notes
Product Label
OKY-T/3-D12 Performance Data and Oscillograms
OKY-T/5-D12 Performance Data and Oscillograms
Tape and Reel Information
Page
1
2
3
4
5
6
8
9
15
21
Connection Diagram
+Vin
F1
On/Off
Control
External
DC
Power
Source
Open = On
Closed = Off
(Positive
On/Off)
Controller
t4XJUDIJOH
t'JMUFST
t$VSSFOU4FOTF
Reference and
Error Amplifier
Common
Figure 1. OKY-T/3, -T/5
Note: Murata Power Solutions strongly recommends an external input fuse, F1.
See specifications.
+Vout
Trim
Common
For full details go to
www.murata-ps.com/rohs
www.murata-ps.com/support
MDC_OKY-T/3,T/5-D12 Series.B15 Page 1 of 21
OKY-T/3,T/5-D12 Series
Adjustable Output 3 and 5-Amp DOSA-SMT DC/DC Converters
TECHNICAL NOTES
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. We
recommend a time delay fuse installed in the ungrounded input supply line
with a value which is approximately twice the maximum line current, calcu-
lated at the lowest input voltage.
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, i.e. IEC/EN/UL 60950-1.
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, converters 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 opera-
tion 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
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 capaci-
tance 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 sluggish or
possibly introduce instability. Do not exceed the maximum rated output capaci-
tance 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 compo-
nents, 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.
TO
OSCILLOSCOPE
+
VIN –
+
–
LBUS
CBUS
CURRENT
PROBE
CIN
+INPUT
-INPUT
CIN = 2 x 100μF, ESR < 700mΩ @ 100kHz
CBUS = 1000μF, ESR < 100mΩ @ 100kHz
LBUS = 1μH
Figure 2. Measuring Input Ripple Current
In figure 3, the two copper strips simulate real-world printed circuit imped-
ances between the power supply and its load. In order to minimize circuit
errors and standardize tests between units, scope measurements should be
made using BNC connectors or the probe ground should not exceed one half-
inch and soldered directly to the test circuit.
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MDC_OKY-T/3,T/5-D12 Series.B15 Page 6 of 21
6 Page OKY-T/3,T/5-D12 Series
Adjustable Output 3 and 5-Amp DOSA-SMT DC/DC Converters
OKY-T/3-D12 PERFORMANCE DATA: Vout = 2.5V
OKY-T/3-D12 Efficiency vs. Line Voltage and Load Current @ 25°C (VOUT = 2.5V)
OKY-T/3-D12 Maximum Current Temperature Derating @ Sea Level
(VIN = 12V, VOUT = 2.5V, airflow is transverse)
100
90
80
70
60
50
40
30
20
10
0
0
VIN = 8.3V
VIN = 12V
VIN = 13.8V
0.5 1
1.5 2
2.5 3
Load Current (Amps)
3.5
3.5
3.3
3.0
2.8 Natural convection
2.5
2.3
2.0
1.8
1.5
1.3
1.0
20 25 30 35 40 45 50 55 60 65 70 75 80 85 90
Ambient Temperature (ºC)
OKY-T/3-D12 OSCILLOGRAMS: Vout = 2.5V
Output Ripple and Noise
(Vin=12V, Vout=2.5V, Iout=3A, Cload=0, ScopeBW=100MHz)
On/Off Enable Startup Delay (Vin=12V, Vout=2.5V, Iout=3A, Cload=0)
Trace 4=Enable In, Trace2=Vout
Step Load Transient Response (Vin=12V, Vout=2.5V, Cload=0, Iout=1.5A to 3A)
Trace 1=Vout, 50 mV/div. Trace 3=Iout, 1A/div.
Step Load Transient Response (Vin=12V, Vout=2.5V, Cload=0, Iout=3A to 1.5A)
Trace 1=Vout, 50 mV/div. Trace 3=Iout, 1A/div.
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MDC_OKY-T/3,T/5-D12 Series.B15 Page 12 of 21
12 Page | ||
Seiten | Gesamt 21 Seiten | |
PDF Download | [ OKY-T-5-D12N-C Schematic.PDF ] |
Teilenummer | Beschreibung | Hersteller |
OKY-T-5-D12N-C | Adjustable Output 3 and 5-Amp DOSA-SMT DC/DC Converters | Murata |
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