RESIDUAL RISK (PER ISO 14971 & IEC60601-1) FOR USER CONSIDERATION
PROTECTION CHARACTERISTICS
Parameter
Over Voltage Protection
4
Over Current Protection
4
Over Temperature Protection
Remote Sense Short Circuit Protection
Remote Sense Reverse Connection Protection
Units
%
V
%Amax
Complies
Complies
Complies
ISOLATION CHARACTERISTICS
Parameter
Isolation
Conditions
Primary to Chassis
Primary to Secondary (2xMOPP)
Secondary to Chassis
Output to Output
MVAC250-xxAFD
MVAC250-xxAF; -xxAFT
MVAC250-xxF
MVAC250-xxAFD
MVAC250-xxAF; -xxAFT
MVAC250-xxF
Min.
1500
4000
500
500
Typ.
Max.
Units
Vac
300
300
350
150
150
250
Earth Leakage Current (under single fault condition):
264Vac, 60Hz, 25°C
Earth Leakage Current (under normal conditions):
264Vac, 60Hz, 25°C
µA
CURRENT SHARING OPTION – MVAC250-xxAFD ONLY
Model Number
Description
Main Output: Current share is achieved using the droop method. Nominal output voltage is achieved at 50% load and output voltage increases/
drops at a rate of:
• 48mv per amp for 12V output
• 192mV per amp for 24V output
• 800mV per amp for 50V output.
Startup of parallel power supplies is not internally synchronized. If more than 250W combined power is needed, start-up synchronization must be
provided by using a common PS_ON signal. To account for ±10% full load current sharing accuracy and the reduction in full load output voltage
due to droop, available output power must be derated by 15% when units are operated in parallel. Current sharing can be achieved with or without
remote sense connected to the common load. If ORing protection is desired, please contact Murata sales for external ORing FET board or external
ORing FET reference circuit design.
Aux (V3) output can be tied together for redundancy but total combined output power must not exceed 10W, external ORing devices must be used.
Fan (V2) can be tied together for redundancy but total combined output power must not exceed 12W, external ORing diodes can be used.
MVAC250-12AFD
MVAC250-24AFD
MVAC250-48AFD
www.murata-ps.com/support
MVAC250.C03
Page 2 of 9
MVAC250 Series
250W 3" x 5" High Density AC-DC Power Supply Converter
EMISSIONS AND IMMUNITY
Characteristic
Input Current Harmonics
Voltage Fluctuation and Flicker
Conducted Emissions
ESD Immunity
Radiated Field Immunity
Electrical Fast Transient Immunity
Surge Immunity
Radiated Field Conducted Immunity
Magnetic Field Immunity
Voltage dips, interruptions
Standard
IEC/EN 61000-3-2
IEC/EN 61000-3-3
EN 55022
FCC Part 15
IEC/EN 61000-4-2
IEC/EN 61000-4-3
IEC/EN 61000-4-4
IEC/EN 61000-4-5
IEC/EN 61000-4-6
IEC/EN 61000-4-8
IEC/EN 61000-4-11
Compliance
Class A
Complies
Class B
Class B
Level 4, Criterion 2
Level 3, Criterion A
Level 4, Criterion A
Level 3, Criterion A
Level 3, 10V/m, Criterion A
Level 3, Criterion A
Level 3, Criterion B
EMI CONSIDERATIONS
For optimum EMI performance, the power supply should be mounted to a metal plate grounded to all 4 mounting holes of the power supply. To comply with safety standards, this
plate must be properly grounded to protective earth (see mechanical dimension notes). Pre-compliance testing has shown the stand-alone power supply to comply with EN55022
Class A radiated emissions. Class B radiated emissions are achievable with a metal enclosure. Radiated emission results vary with system enclosure and cable routing paths.
SAFETY CONSIDERATIONS
1. This power supply is a component level power supply intended for use in Class I or Class II applications. Secondary ground traces need to be suitably isolated
from primary ground traces when used in Class II applications.
2. When the power supply is used in Class II equipment, all ground traces and components connected to the primary side are considered primary for spacing and
insulation considerations.
STATUS AND CONTROL SIGNALS – MVAC250-xxAFD ONLY
Parameter
PS_ON
Models
Conditions
All models except This signal must be pulled low (sink current >2mA) to +5V_AUX_RTN to turn on the main and Fan (V2) output. The +5V_AUX output is independent
as noted below. of the PS_ON signal and comes up automatically when the input AC or input DC voltage is applied within their specified operating ranges.
This pin is pulled high internally and so all three outputs (main, Fan output and +5V_AUX) come up automatically when the input AC or input DC voltage
MVAC250-xxAFT
is applied within their specified operating ranges. Pulling this pin low (sink current >2mA) to +5V_AUX_RTN will disable the main and fan outputs.
Open collector logic goes high 50-200 msec after main output is in regulation; it goes low at least 6 msec before loss of regulation. Internal 10K pull
All models
up to +5V_AUX is provided. Applications using PWR_OK signal should maintain a minimum load of 5W on the main or fan output.
PWR_OK
1. Noise and ripple is measured at an oscilloscope jack on the output, 20MHz bandwidth, and with
0.1µF ceramic and 10µF aluminum electrolytic capacitors across the output pins.
2. Unless otherwise specified all measurements are taken at 120Vac input and 25°C ambient
temperature.
3. Fan (V2) regulation band applies from 0.1A to 1A load with a minimum of 10W load on the main
(V1) output.
4. Fan (V2) has overvoltage protection (tracking V1) and short circuit protection. Overloading the Fan
(V2) output can result in permanent damage to the unit.
5. 24V and 50V models may exhibit up to 5% turn on overshoot for loads less than 4% of full load.
6. See current sharing option section for droop characteristics.
7. No load Input power varies by model and by input line. Measurement is difficult to make due to burst
mode operation. Please contact Murata sales if additional information is required.
8. All three output returns are isolated from each other (see isolation characteristics section); the returns
may be tied together externally.
9. Load steps beginning from combined loads on the main and fan outputs of less than 5W may
result in transient undershoots outside of the spec limits.
PART NUMBER STRUCTURE
MV A x yyy
-
zz hhh
Murata Manufacturing Corp.
Modification Code Options
A = Aux 5V Standby Voltage
F = Aux 12V Fan Output
D = Droop Current Share
T = Terminal Output Connector
R = Terminal Output Connector with Internal Or-ing Solution and Droop Current Share
Main Output Voltage (V)
(12, 24, 28, or 50)
Output Power (W)
(40, 65, 120, 160, 250, 400, or 750)
Form Factor Outline
A = 2x4", 3x5", or 4x7"
Outline Detail
B & D = 2x4"
C = 3x5"
F = 4x7"
www.murata-ps.com/support
MVAC250.C03
Page 3 of 9
MVAC250 Series
250W 3" x 5" High Density AC-DC Power Supply Converter
PERFORMANCE DATA
MVAC250-12F Efficiency
95
93
91
MVAC250-24F Efficiency
95
93
Efficiency %
89
87
85
83
81
0
10
20
30
40
50
60
70
80
90
100
115 Vin
230 Vin
Efficiency %
90 Vin
91
89
87
85
83
81
0
10
20
30
40
50
60
70
80
90
100
90 Vin
115 Vin
230 Vin
Load %
MVAC250-48F Efficiency
95
93
91
Load %
Inrush Current
Efficiency %
90 Vin
115 Vin
230 Vin
89
87
85
83
81
0
10
20
30
40
50
60
70
80
90
100
Load %
Time: 100 msec/div, Ch1: 500 V/div, Ch4: 20 A/div, Vin: 264 VAC, Ipk = 15.1 A AC
applied at peak of sine wave
www.murata-ps.com/support
MVAC250.C03
Page 4 of 9
MVAC250 Series
250W 3" x 5" High Density AC-DC Power Supply Converter
THERMAL CONSIDERATIONS
System thermal management is critical to the performance and reliability of the MVAC series power supplies. Performance derating curves are provided
which can be used as a guideline for what can be achieved in a system configuration with controlled airflow at various input voltage conditions.
The air flow curves are generated using an AMCA 210-99 and ASHRAE 51-1999 compliant wind tunnel with heated inlet air and a controlled CFM
providing a duct test section having a calculated average LFM. A correlation between the test setup and the actual system environment is paramount to
understanding what can be achieved in an actual system. In a power supply of this density, cooling air moving both through the unit as well as around the
unit strongly influences local temperatures. The wind tunnel test setup was constructed to produce a flow with a slight back pressure to induce both flow
conditions by providing a small gap between the power supply and duct walls of 0.5" (13mm). The optimal and characterized airflow direction is from the
input connector to the output connector (see diagram below). The P-Q flow curve for this test setup is also shown below.
13mm [0.5in] all sides
P-Q CURVE, DUCTED FLOW
Power Supply
Air Flow
Static Pressure (in. w.g.)
0.0100
0.0075
*
Ambient Temperature
Measurement
Output Connector
Input Connector
64mm [2.5in]
0.0050
0.0025
0.0000
0
2.5
5
7.5
10
12.5
15
17.5
20
22.5
AIRFLOW-(CFM @ 0.075 lbs/cu ft air density)
The natural convection data is obtained from a horizontally mounted power supply with un-obstructed flow at room temperature. At elevated temperature
the power supply data is taken while it is surrounded by a large vented enclosure to minimize forced cross flows inherent in the elevated temperature test
京公网安备 11010802033920号
Copyright © 2005-2026 EEWORLD.com.cn, Inc. All rights reserved
电子工程世界
