Enhance CFX12V Version V1.0 Power Supply Design Guide

CFX12V Power Supply Design Guide Rev 1.0

Compact Form Factor with 12-Volt Connector

CFX12V

Compact Form Factor with 12-Volt Connector

Power Supply Design Guide

Version 1.0

Revision History

Version Release Date Notes

0.7 July, 2003

0.9 August, 2003

1.0 November 2003

• First Release

• Updated Table 6

• Updated Figure 7 mechanical drawing.

• Modified main power connector in section 3.7.1 and Figure 9

• Name change to CFX12V Compact Form Factor with 12V

Connector.

• Modified definition of Monotonically in Section 1.2

• Changed Section 2.1 to AC Input

Changed 270 Watt power configuration to 275 Watt

•

configuration and added second 12 V rail in Section 2.2.3,
Section 2.2.5, Section 3.2.2 and Table 5, Table 7 and
Table

• Updated information in Table 9, Table 10 and Table 11.

• Updated fan size information in Section 3.2.1.and Section

3.3.

• Updated main power connector in Section 3.7, Section 3.7.1

and Figure 9

•

Updated peripheral power connector in Section 3.7.2

•

Updated floppy power connector in Section 3.7.3

•

Updated 12 V power connector in Section 3.7.4

•

Update OVP information in Section 2.4.1 and in Table 14

18.

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CFX12V Power Supply Design Guide Rev 1.0

Compact Form Factor with 12-Volt Connector

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other countries.

*Other names and brands may be claimed as the property of others.

Copyright  Intel Corporation 2003.

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Contents

1 Introduction .................................................................................................... 6

1.1 Scope…. ........................................................................................................................6

1.2 Terminology ...................................................................................................................6

2 Electrical ......................................................................................................... 8

2.1 AC Input. ........................................................................................................................8

2.1.1 Input Over Current Protection.......................................................................... 8

2.1.2 Inrush Current Limiting .................................................................................... 8

2.1.3 Input Under Voltage......................................................................................... 9

2.1.4 Regulatory ....................................................................................................... 9

2.1.5 Catastrophic Failure Protection ..................................................................... 10

2.2 DC Output .................................................................................................................... 10

2.2.1 DC Voltage Regulation ..................................................................................10

2.2.2 Remote Sensing ............................................................................................11

2.2.3 Typical Power Distribution .............................................................................11

2.2.4 Power Limit / Hazardous Energy Levels........................................................ 14

2.2.5 Efficiency General .........................................................................................15

2.2.6 Output Ripple/Noise ......................................................................................16

2.2.7 Output Transient Response........................................................................... 17

2.2.8 Capacitive Load............................................................................................. 18

2.2.9 Closed-loop Stability...................................................................................... 18

2.2.10 +5 VDC / +3.3 VDC Power Sequencing ........................................................ 18

2.2.11 Voltage Hold-up Time ....................................................................................18

2.3 Timing / Housekeeping / Control.................................................................................. 19

2.3.1 PWR_OK .......................................................................................................19

2.3.2 PS_ON# ........................................................................................................20

2.3.3 +5 VSB .......................................................................................................... 21

2.3.4 Power-on Time .............................................................................................. 21

2.3.5 Rise Time ......................................................................................................21

2.3.6 Overshoot at Turn-on / Turn-off..................................................................... 21

2.3.7 Reset after Shutdown ....................................................................................21

2.3.8 +5 VSB at AC Power-down ...........................................................................22

2.4 Output Protection ......................................................................................................... 22

2.4.1 Over Voltage Protection ................................................................................22

2.4.2 Short-circuit Protection .................................................................................. 22

2.4.3 No-load Operation ......................................................................................... 22

2.4.4 Over Current Protection................................................................................. 22

2.4.5 Over-temperature Protection .........................................................................23

2.4.6 Output Bypass ...............................................................................................23

3 Mechanical .................................................................................................... 24

3.1 Labeling /Marking......................................................................................................... 24

3.2 Physical Dimensions ....................................................................................................24

3.2 Thermal Requirements................................................................................................. 25

3.2.1 Fan and Venting ............................................................................................ 25

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3.2.2 Airflow and Acoustics ....................................................................................25

3.3 Airflow / Fan ................................................................................................................. 27

3.6 AC Connector............................................................................................................... 27

3.7 DC Connectors............................................................................................................. 27

3.7.1 Main Power Connector ..................................................................................29

3.7.2 Peripheral Connector(s) ................................................................................29

3.7.3 Floppy Drive Connector................................................................................. 29

3.7.4 12 V Power Connector ..................................................................................30

3.7.5 Serial ATA Power Connector......................................................................... 30

4 Environmental .............................................................................................. 31

4.1 Temperature................................................................................................................. 31

4.2 Thermal Shock (Shipping)............................................................................................ 31

4.3 Relative Humidity ......................................................................................................... 31

4.4 Altitude Requirement.................................................................................................... 31

4.5 Mechanical Shock ........................................................................................................ 31

4.6 Random Vibration ........................................................................................................31

4.7 Acoustics......................................................................................................................32

4.8 Ecological Requirements .............................................................................................32

5 Safety............................................................................................................. 33

5.1 North America .............................................................................................................. 33

5.2 International .................................................................................................................33

6 System Cooling Considerations................................................................. 34

7 Reliability ...................................................................................................... 34

8 Applicable Documents ................................................................................ 35

4

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Figures

Figure 1: Cross Loading Graph for 220W configuration ............................................................12

Figure 2. Cross Loading Graph for 240W Configuration............................................................ 13

Figure 3. Cross Loading Graph for 275W Configuration............................................................ 14

Figure 4. Differential Noise Test Setup ......................................................................................17

Figure 5. Power Supply Timing..................................................................................................19

Figure 6. PS_ON# Signal Characteristics.................................................................................. 20

Figure 7. Mechanical Outline .....................................................................................................24

Figure 8. AMCA* Standard 210 .................................................................................................26

Figure 9. Connectors (Pin-side view, not to scale) ....................................................................28

Figure 10. Serial ATA connector.................................................................................................30

Tables

Table 1 .AC Input Line Requirements.......................................................................................... 8

Table 2. DC Output Voltage Regulation..................................................................................... 10

Table 3. Typical Power Distribution for 220 W Configurations................................................... 12

Table 4. Typical Power Distribution for 240 W Configurations................................................... 13

Table 5. Typical Power Distribution for 275 W Configurations................................................... 14

Table 6. Efficiency Vs Load .......................................................................................................15

Table 7. Loading Tables for Efficiency Measurements ..............................................................15

Table 8. Energy Star Input Power Consumption........................................................................ 16

Table 9. DC Output Noise/Ripple............................................................................................... 16

Table 10. DC Output Transient Step Sizes................................................................................. 17

Table 11. Output Capacitive Loads............................................................................................. 18

Table 12. PWR_OK Signal Characteristics................................................................................. 19

Table 13. PS_ON# Signal Characteristics ..................................................................................20

Table 14. Over Voltage Protection.............................................................................................. 22

Table 15. Airflow and Acoustic Recommendations..................................................................... 25

Table 16 Loading for Acoustic Test for 220 Watts .....................................................................26

Table 17. Loading for Acoustic Test for 240 Watts .....................................................................26

Table 18. Loading for Acoustic Test for 275 Watts .....................................................................26

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1 Introduction

1.1 Scope

This document provides design suggestions for power supply(s) that support Balanced
Technology Extended (BTX) based systems. The power supply(s) are primarily intended
for use with small form factor system designs (10 –15 liters in total system volume). It
should not be inferred that all power supplies built to support Balanced Technology
Extended (BTX) based systems must conform exactly to the content of this document,
though there are key parameters that define mechanical fit across a common set of
platforms. Since power supply needs vary depending on system configuration, the design
specifics described are not intended to support all possible systems.

1.2 Terminology

The following terms are used in this document:

Term Description

Required

Recommended

Optional

B

A

CFM

Monotonically

The status given to items within this design guide, which are required
to meet design guide and a large majority of system applications.

The status given to items within this design guide, which are not
required to meet design guide, however, are required by many system
applications.

The status given to items within this design guide, which are not
required to meet design guide, however, some system applications
may optionally use these features.

Declared sound power, LwAd. The declared sound power level shall
be measured according to ISO* 7779 for the power supply and
reported according to ISO 9296.

Cubic Feet per Minute (airflow).

A waveform changes from one level to another in a steady fashion,
without oscillation.

Noise

6

The periodic or random signals over frequency band of 0 Hz to 20
MHz.

CFX12V Power Supply Design Guide Rev 1.0

Compact Form Factor with 12-Volt Connector

Term Description

Overcurrent

PFC

Ripple

Rise Time

Surge

VSB or Standby
Voltage

MTBF

PWR_OK

A condition in which a supply attempts to provide more output current
than the amount for which it is rated. This commonly occurs if there is
a "short circuit" condition in the load attached to the supply.

Power Factor Corrected.

The periodic or random signals over a frequency band of 0 Hz to 20
MHz.

Rise time is defined as the time it takes any output voltage to rise from
10% to 95% of its nominal voltage.

The condition where the AC line voltage rises above nominal voltage.

An output voltage that is present whenever AC power is applied to the
AC inputs of the supply.

Mean time between failure.

PWR_OK is a “power good” signal used by the system power supply
to indicate that the +5VDC, +3.3 VDC and +12VDC outputs are above
the undervoltage thresholds of the power supply.

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Compact Form Factor with 12-Volt Connector

2 Electrical

The following electrical requirements are required and must be met over the environmental
ranges as defined in Section 5 (unless otherwise noted).

2.1 AC Input

Table 1, lists AC input voltage and frequency requirements for continuous operation. The
power supply shall be capable of supplying full-rated output power over two input voltage
ranges rated 100-127 VAC and 200-240 VAC rms nominal. The correct input range for
use in a given environment may be either switch-selectable or auto-ranging. The power
supply shall automatically recover from AC power loss. The power supply must be able to
start up under peak loading at 90 VAC.

Table 1. AC Input Line Requirements

Parameter Minimum Nominal

Vin (115 VAC) 90 115 135 VAC

Vin (230 VAC) 180 230 265 VAC

Vin Frequency 47 -- 63 Hz

Iin (115 VAC) 6 A rms

Iin (230 VAC) 3 A rms

(1)

Note:

Nominal voltages for test purposes are considered to be within ±1.0 V of nominal.

(1)

Maximum Unit

2.1.1 Input Over Current Protection

The power supply is required to incorporate primary fusing for input over current
protection to prevent damage to the power supply and meet product safety requirements.

1

Fuses should be slow-blow–type or equivalent to prevent nuisance trips.

2.1.2 Inrush Current Limiting

Maximum inrush current from power-on (with power-on at any point on the AC sine) and
including, but not limited to, three line cycles, shall be limited to a level below the surge
rating of the input line cord, AC switch if present, bridge rectifier, fuse, and EMI filter
components. Repetitive ON/OFF cycling of the AC input voltage should not damage the
power supply or cause the input fuse to blow.

rms

rms

1

For Denmark and Switzerland international safety requirements, if the internal over current protective devices exceed 8A for Denmark

and 10A for Switzerland, then the power supply must pass international safety testing to EN 60950 using a maximum 16A over­current protected branch circuit, and this 16A (time delay fuse) branch circuit protector must not open during power supply abnormal
operation (output short circuit and component fault) testing.

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2.1.3 Input Under Voltage

The power supply is required to contain protection circuitry such that the application of an
input voltage below the minimum specified in Section 2.1, Table 1, shall not cause damage
to the power supply.

2.1.4 Regulatory

The power supply is required to be tested and comply with the most current version
of the following regulatory specification requirements and/or standards

2.1.4.1 PRODUCT SAFETY

UL* 60950, 3rd Edition –CAN/CSA-C22.2-60950-00,

EN*60 950, 3rd Edition

IEC*60 950, 3rd Edition (CB Report to include all national deviations)

EU* Low Voltage Directive (73/23/EEC) (CE Compliance)

GB4943-90 CCIB* (China)

2.1.4.2 ELECTROMAGNETIC CAMPATIBILITY

FCC*, Class B, Part 15 (Radiated & Conducted Emissions)

CISPR* 22 / EN55022, 3rd Edition (Radiated & Conducted Emissions)

EN55024 (ITE Specific Immunity)

EN 61000-4-2 – Electrostatic Discharge

EN 61000-4-3– Radiated RFI Immunity

EN 61000-4-4– Electrical Fast Transients.

EN 61000-4-5 – Electrical Surge

EN 61000-4-6 – RF Conducted

EN 61000-4-8 – Power Frequency Magnetic Fields

EN 61000-4-11 – Voltage Dips, Short Interrupts and Fluctuations

EN61000-3-2 (Harmonics)

EN61000-3-3 (Voltage Flicker)

EU EMC Directive ((8/9/336/EEC) (CE Compliance)

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2.1.4.3 Other Certifications and/or Declarations

GB925 (China/CCC*)

CNS13438 (Taiwan/BSMI*)

AS/NZ3548 (Australia/C-tick* based on CISPR22)

2.1.5 Catastrophic Failure Protection

It is required that should a component failure occur, the power supply should not exhibit
any of the following:

• Flame

• Excessive smoke

• Charred PCB

• Fused PCB conductor

• Startling noise

• Emission of molten material

• Earth ground fault (short circuit to ground or chassis enclosure)

2.2 DC Output

2.2.1 DC Voltage Regulation

The DC output voltages are required to remain within the regulation ranges shown in
Table 2, when measured at the load end of the output connectors under all line, load, and
environmental conditions specified in Section 4.

Table 2. DC Output Voltage Regulation

Output Range Min. Nom. Max. Unit

(1)

±5% +11.40 +12.00 +12.60 Volts

(1)

±5% +11.40 +12.00 +12.60 Volts

(2)

±5% +3.14 +3.30 +3.47 Volts

Note:.

(2)

+12V1DC

+12V2DC

+5VDC ±5% +4.75 +5.00 +5.25 Volts

+3.3VDC

-12VDC ±10% -10.80 -12.00 -13.20 Volts

+5VSB ±5% +4.75 +5.00 +5.25 Volts

(1)

At +12 VDC peak loading, regulation at the +12 VDC output can go to ± 10%.

Voltage tolerance is required at main connector and S-ATA connector (if used).

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Compact Form Factor with 12-Volt Connector

2.2.2 Remote Sensing

The +3.3 VDC output should have provisions for remote sensing to compensate for
excessive cable drops. The default sense should be connected to pin 11 of the main power
connector. The power supply should draw no more than 10 mA through the remote sense
line to keep DC offset voltages to a minimum.

2.2.3 Typical Power Distribution

DC output power requirements and distributions will vary based on specific system options
and implementation.

Significant dependencies include the quantity and types of processors, memory, add-in
card slots, and peripheral bays, as well as support for advanced graphics or other features.
through and Figure 1 through Figure 3 shows the power distribution and cross loading
tables for power supplies in the range of 220 W to 275W. These are recommended but it is

ultimately the responsibility of the designer to define a power budget for a given target
product and market.

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Compact Form Factor with 12-Volt Connector

Table 3. Typical Power Distribution for 220 W Configurations

Output

+12 VDC 1.0 15.0 16.0

+5 VDC 0.3 13.5

+3.3 VDC 0.5 12.0

-12 VDC 0 0.3

+5 VSB 0 2.0 2.5

Note: Total combined output of 3.3 V and 5 V is ≤ 100 W

Minimum Current

(amps)

Rated Current

(amps)

Peak Current

(amps)

Figure 1: Cross Loading Graph for 220W configuration

220W Cross Regulation

(5V rail + 3.3V rail vs. 12V)

120

100

80

60

40

Combined Power
(5V rail + 3.3V rail)

20

5V + 3.3V power (watts)

0

0 50 100 150 200

12V power (watts)

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Compact Form Factor with 12-Volt Connector

Table 4.Typical Power Distribution for 240 W Configurations

Output

+12 VDC 1.0 16.0 17.0

+5 VDC 0.3 14.5

+3.3 VDC 0.5 13.0

-12 VDC 0 0.3

+5 VSB 0 2.0 2.5

Note: Total combined output of 3.3 V and 5 V is ≤ 110 W

Minimum Current

(amps)

Rated Current

(amps)

Peak Current

(amps)

Figure 2. Cross Loading Graph for 240W Configuration

240W Cross Regulation

(5V rail + 3.3V rail vs. 12V)

120

100

80

60

40

Combined Power
(5V rail + 3.3V rail)

20

5V + 3.3V power (watts)

0

0 100 200 300

12V power (watts)

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Compact Form Factor with 12-Volt Connector

Table 5. Typical Power Distribution for 275 W Configurations

Output

+12 V1DC 1.0 5.0 7.0

+12V2DC Ŧ

+5 VDC 0.3 14.5

+3.3 VDC 0.5 13.0

-12 VDC 0 0.3

+5 VSB 0 2.0 2.5

Note: Total combined output of 3.3 V and 5 V is ≤ 110 W

Ŧ12V2 support processor power requirements and must be an isolated voltage

Minimum

Current (amps)

Rated Current

(amps)

1.0 13.5

Peak Current

(amps)

Figure 3. Cross Loading Graph for 275W Configuration

275W Cross Regulation

(5V rail + 3.3V rail vs. 12V)

120

100

80

60

Combined Power
(5V rail + 3.3V rail)

40

20

5V + 3.3V power (watts)

0

0 100 200 300

12V power (watts)

2.2.4 Power Limit / Hazardous Energy Levels

Under normal or overload conditions, it is required that no output shall continuously provide 240 VA under any
conditions of load including output short circuit, per the requirement of
specification.

14

UL 1950/CSA 950 / EN 60950/IEC 950

CFX12V Power Supply Design Guide Rev 1.0

Compact Form Factor with 12-Volt Connector

2.2.5 Efficiency General

The power supply should have a required minimum efficiency as stated in Table 6 and when cost effective
provide the recommended efficiency in Table 6. The efficiency of the power supply should be tested at
nominal input voltage of 115VAC input and 230VAC input, under the load conditions defined in Table 6, and
under the temperature and operating conditions defined in Section 3. The loading condition for testing
efficiency shown in Table 6 represents a fully loaded system, a 50% loaded system (typical load), and a 20%
loaded (light load) system.

Table 6. Efficiency Vs Load

Loading

Required: Minimum Efficiency

Recommended: Minimum Efficiency

Full load Typical load Light load

70% 70% 60%

75% 80% 67%

Table 7. Loading Tables for Efficiency Measurements

220W (loading shown in Amps)

Loading +12V +5V +3.3V -12V +5Vsb

Full 13.0 7.8 6.0 0.2 1.0

Typical 8.0 3.0 5.0 0.1 1.0

Light 3.0 0.3 0.5 0 1.0

240W (loading shown in Amps)

Loading +12V +5V +3.3V -12V +5Vsb

Full 14.5 8.0 6.4 0.2 1.0

Typical 7.0 4.0 3.0 0.1 1.0

Light 3.4 0.4 0.7 0 1.0

275W (loading shown in Amps)

Loading +12V1 12V2 +5V +3.3V -12V +5Vsb

Full 4.0 12.0 9.5 7.5 0.2 1.0

Typical 2.0 6.0 4.5 4.0 0.1 1.0

Light 1.0 2.3 0.4 0.7 0 1.0

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2.2.5.1 Energy Star*

The “Energy Star” efficiency requirements of the power supply depend on the intended system configuration.
In the low power / sleep state (S1 or S3) the system should consume power in accordance with the values
listed in Table 8.

Table 8. Energy Star Input Power Consumption

Maximum Continuous Power Rating of

Power Supply

< 200 W < 15 W

> 200 W < 300 W < 20 W

> 300 W < 350 W < 25 W

> 350 W < 400 W < 30 W

> 400 W 10% of the maximum continuous output rating

Note: To help meet the “Energy Star” system requirements, it is recommended that the power supply have ≥ 50% efficiency
at light load and in standby mode.

RMS Watts from the AC Line in Sleep/low-Power

Mode

2.2.5.2 Other Low Power System Requirements

To help meet the Blue Angel* system requirements, RAL-UZ 78, US Presidential executive order 13221, future
EPA requirements, and other low Power system demands, therefore is it recommended that the +5 VSB standby
supply efficiency should be as high as possible. Standby efficiency is measured with the main outputs off
(PS_ON# high state). Standby efficiency should be greater than 50% with a load of 100mA.

2.2.6 Output Ripple/Noise

The output ripple/noise requirements listed in Table 9 should be met throughout the load ranges specified in
Section 2.2.3 and under all input voltage conditions as specified in Section 3.1.

Ripple and noise are defined as periodic or random signals over a frequency band of 10 Hz to 20 MHz.
Measurements shall be made with an oscilloscope with 20 MHz of bandwidth. Outputs should be bypassed at
the connector with a 0.1µF ceramic disk capacitor and a 10µF electrolytic capacitor to simulate system loading.
See Figure 4.

Table 9. DC Output Noise/Ripple

Output Maximum Ripple and Noise

(mVpp)

+12 V1DC 120

+12 V2DC 120

+5 VDC 50

+3.3 VDC 50

-12 VDC 120

+5 VSB 50

16

CFX12V Power Supply Design Guide Rev 1.0

A

A

A

Compact Form Factor with 12-Volt Connector

Power Supply

C Hot

C Neutral

C Ground

General Notes:

1. Lo ad the o utpu t with its m inim um load
curre nt.

2. Connect the probes as shown.

3. Repeat the measurement with maximum
load on the o utpu t.

Filter Note:

0.1uf – Kemet*, C1206C104K5RAC or equivalent
10uf - United Chemi-con*, 293D106X0025D2T or
equivale nt

V out

V return

10uf

0.1uf

Scope Note:

Use Te ktron ix* TD S4 60 Osc illos cop e or
equivalent and a P6046 probe or equivalent.

Figure 4. Differential Noise Test Setup

Load

Load must be
isola ted fro m the
ground of the
power supply.

Scope

2.2.7 Output Transient Response

Table 10 summarizes the expected output transient step sizes for each output. The transient load slew rate is
= 1.0 A/µs.

Table 10. DC Output Transient Step Sizes

Output

+12 V1DC 50%

+12 V2DC 80%

+5 VDC 30%

+3.3 VDC 30%

-12 VDC 0.1 A

+5 VSB 0.5 A

Note: For example, for a rated +5 VDC output of 14 A, the transient step would be 30% × 14 A = 4.2 A

Output voltages should remain within the regulation limits of Table 2, Section 2.2.1, for instantaneous
changes in load as specified in Table 10 and for the following conditions:

• Simultaneous load steps on the +12 VDC, +5 VDC, and +3.3 VDC outputs (all steps occurring in the same

direction)

• Load-changing repetition rate of 50 Hz to 10 kHz

• AC input range per Section 3.1 and Capacitive loading per Table 11

Maximum Step Size

(% of rated output amps)

Maximum Step Size

(amps)

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2.2.8 Capacitive Load

The power supply should be able to power up and operate with the regulation limits defined in Table 2, Section

2.2.1, with the following capacitances simultaneously present on the DC outputs.

Table 11. Output Capacitive Loads

Output Capacitive Load

µF)

(

+12 V1DC 5,000

+12 V2DC 5,000

+5 VDC 10,000

+3.3 VDC 6,000

-12 VDC 350

+5 VSB 350

2.2.9 Closed-loop Stability

The power supply is required to be unconditionally stable under all line/load/transient load conditions including
capacitive loads specified in Section 2.2.8. A minimum of 45 degrees phase margin and 10 dB gain margin is
recommended at both the maximum and minimum loads.

2.2.10 +5 VDC / +3.3 VDC Power Sequencing

The +12 VDC and +5 VDC output levels must be equal to or greater than the +3.3 VDC output at all times
during power-up and normal operation. The time between the +12 V1DC/12 V2DC or +5 VDC output reaching
its minimum in-regulation level and +3.3 VDC reaching its minimum in-regulation level must be

≤ 20 ms.

2.2.11 Voltage Hold-up Time

The power supply should maintain output regulations per Section 2.2.1 despite a loss of input power at the low­end nominal range—115 VAC / 57 Hz or 230 VAC / 47 Hz - at maximum continuous output load as applicable
for a minimum of 17 ms.

18

2.3 Timing / Housekeeping / Control

VAC

PS_ON#

+12VDC

+5VDC

+3.3VDC

O/P's

}

PWR_OK

95%

10%

T2

T3

T4

CFX12V Power Supply Design Guide Rev 1.0

Compact Form Factor with 12-Volt Connector

T5T1

~

~

~

~

T6

PWR_OK Sense Level = 95% of nominal

Figure 5. Power Supply Timing

Notes: T1 is defined in Section 2.3.4. , T2 in Section 2.3.5. ,T3, T4, T5, and T6 are defined in Table 12.

2.3.1 PWR_OK

PWR_OK is a “power good” signal. This signal should be asserted high by the power supply to indicate that
the +12 VDC, +5 VDC, and +3.3 VDC outputs are above the under voltage thresholds listed in Table 2
in Section 2.2.1 and that sufficient mains energy is stored by the converter to guarantee continuous power
operation within specification for at least the duration specified in Section 2.2.11, “Voltage Hold-up Time.”
Conversely, PWR_OK should be de-asserted to a low state when any of the +12 VDC, +5 VDC, or +3.3 VDC
output voltages falls below its under voltage threshold, or when mains power has been removed for a time
sufficiently long such that power supply operation cannot be guaranteed beyond the power-down warning time.
The electrical and timing characteristics of the PWR_OK signal are given in Table 12 and in Figure 5.

Table 12. PWR_OK Signal Characteristics

Signal Type +5 V TTL compatible

Logic level low < 0.4 V while sinking 4 mA

Logic level high Between 2.4 V and 5 V output while sourcing 200 µA

High-state output impedance

PWR_OK delay 100 ms < T3 < 500 ms

PWR_OK rise time

AC loss to PWR_OK hold-up time

Power-down warning

Ω from output to common

1 k

≤ 10 ms

T

4

≥ 16 ms

T

5

≥ 1 ms

T

6

timing_3_5_12b

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2.3.2 PS_ON#

PS_ON# is an active-low, TTL-compatible signal that allows a motherboard to remotely control the power

*

supply in conjunction with features such as soft on/off, Wake on LAN
pulled to TTL low, the power supply should turn on the four main DC output rails: +12 VDC, +5 VDC, +3.3
VDC, and -12 VDC. When PS_ON# is pulled to TTL high or open-circuited, the DC output rails should not
deliver current and should be held at zero potential with respect to ground. PS_ON# has no effect on the +5
VSB output, which is always enabled whenever the AC power is present. Table 13 lists PS_ON# signal
characteristics.

The power supply shall provide an internal pull-up to TTL high. The power supply shall also provide de-bounce
circuitry on PS_ON# to prevent it from oscillating on/off at startup when activated by a mechanical switch. The
DC output enable circuitry must be SELV-compliant.

The power supply shall not latch into a shutdown state when PS_ON# is driven active by pulses between 10ms
to 100ms during the decay of the power rails.

Table 13. PS_ON# Signal Characteristics

Parameter Minimum Maximum

VIL, Input Low Voltage 0.0 V 0.8 V

IIL, Input Low Current (Vin = 0.4 V) -1.6 mA

VIH, Input High Voltage (Iin = -200 µA) 2.0 V

VIH open circuit, Iin = 0 5.25 V

, or wake-on-modem. When PS_ON# is

≤

0.8 V
PS is

enabled

Hysteresis ≥ 0.3 V

0.8 2.0

PS_ON# Voltage

≥

2.0 V
PS is

disabled

Disable

Enable

Figure 6. PS_ON# Signal Characteristics

5.25 = Maximum Open­Circuit Voltage

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2.3.3 +5 VSB

+5 VSB is a standby supply output that is active whenever the AC power is present. This output provides a
power source for circuits that must remain operational when the five main DC output rails are in a disabled
state. Example uses include soft power control, Wake on LAN, wake-on-modem, intrusion detection, or
suspend state activities.

The +5 VSB output should be capable of delivering a minimum of 2.0 A. at +5 V ± 5% to external circuits. The
power supply is required to provide the required power during a "wake up" event. If an external USB device
generates the event, there may be peak currents as high as 2.5 A., lasting no more than 500 ms.

Over current protection is required on the +5 VSB output regardless of the output current rating. This ensures
the power supply will not be damaged if external circuits draw more current than the supply can provide.

2.3.4 Power-on Time

The power-on time is defined as the time from when PS_ON# is pulled low to when the +12 VDC, +5 VDC, and
+3.3 VDC outputs are within the regulation ranges specified in Section 2.2.1. The power-on time shall be less
than 500 ms (T

< 500 ms).

1

+5 VSB shall have a power-on time of two seconds

maximum after application of valid AC voltages.

2.3.5 Rise Time

The output voltages shall rise from ≤10% of nominal to within the regulation ranges specified in Section 2.2.1
within 0.2 ms to 20 ms (0.2 ms

There must be a smooth and continuous ramp of each DC output voltage from 10% to 90% of its final set point
within the regulation band, while loaded as specified in Section 2.2.1.

The smooth turn-on requires that, during the 10% to 90% portion of the rise time, the slope of the turn-on
waveform must be positive and have a value of between 0 V/ms and [V
ms segment of the 10% to 90% rise time waveform, a straight line drawn between the end points of the
waveform segment must have a slope

≤ T

2

≤ 20 ms).

≥ [V

out

, nominal / 20] V/ms.

, nominal / 0.1] V/ms. Also, for any 5

out

2.3.6 Overshoot at Turn-on / Turn-off

The output voltage overshoot upon the application or removal of the input voltage, or the assertion/de­assertion of PS_ON#, under the conditions specified in Section 3.1, shall be less than 10% above the nominal
voltage. No voltage of opposite polarity shall be present on any output during turn-on or turn-off.

2.3.7 Reset after Shutdown

If the power supply latches into a shutdown state because of a fault condition on its outputs, the power supply
shall return to normal operation only after the fault has been removed and the PS_ON# has been cycled
OFF/ON with a minimum OFF time of one second.

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2.3.8 +5 VSB at AC Power-down

After AC power is removed, the +5 VSB standby voltage output should remain at its steady state value for the
minimum hold-up time specified in Section 2.2.11 until the output begins to decrease in voltage. The decrease
shall be monotonic in nature, dropping to 0.0 V. There shall be no other disturbances of this voltage at or
following removal of AC power.

2.4 Output Protection

2.4.1 Over Voltage Protection

The over voltage sense circuitry and reference shall reside in packages that are separate and distinct from the
regulator control circuitry and reference. No single point fault shall be able to cause a sustained over voltage
condition on any or all outputs. The supply shall provide latch-mode over voltage protection as defined in
Table 14.

Table 14. Over Voltage Protection

Output Minimum Nominal Maximum Unit

+12 V1DC and 12V2DC 13.4 15.0 15.6 Volts

+5 VDC 5.74 6.3 7.0 Volts

+3.3 VDC 3.76 4.2 4.3 Volts

2.4.2 Short-circuit Protection

An output short circuit is defined as any output impedance of less than 0.1 ohms. The power supply shall shut
down and latch off for shorting the +3.3 VDC, +5 VDC, or +12 V1 DC/12V2 DC rails to return or any other rail.
Shorts between main output rails and +5 VSB shall not cause any damage to the power supply. The power
supply shall either shut down and latch off or fold back for shorting the negative rails. +5 VSB must be capable
of being shorted indefinitely, but when the short is removed, the power supply shall recover automatically or by
cycling PS_ON#. The power supply shall be capable of withstanding a continuous short circuit to the output
without damage or overstress to the unit (for example, to components, PCB traces, and connectors) under the
input conditions specified in Section 3.1.

2.4.3 No-load Operation

No damage or hazardous condition should occur with all the DC output connectors disconnected from the load.
The power supply may latch into the shutdown state.

2.4.4 Over Current Protection

Overload currents applied to each tested output rail cause the output to trip before reaching or exceeding 240
VA. For testing purposes, the overloaded currents should be ramped at a minimum rate of 10 A/s starting from
full load.

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2.4.5 Over-temperature Protection

As an option, it is recommended that the power supply may include an over-temperature protection sensor,
which can trip and shut down the power supply at a preset temperature point. Such an overheated condition is
typically the result of internal current overloading or a cooling fan failure. If the protection circuit is non­latching, then it should have hysteresis built in to avoid intermittent tripping.

2.4.6 Output Bypass

The output return may be connected to the power supply chassis, and will be connected to the system chassis
by the system components.

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3 Mechanical

3.1 Labeling /Marking

The following is a non-inclusive list of suggested markings for each power supply unit. Product regulation
stipulations for sale into various geographies may impose additional labeling requirements.

• Manufacturer information: manufacturer's name, part number and lot date code, etc., in human-readable

text and/or bar code formats

• Nominal AC input operating voltages (100-127 VAC and 200-240 VAC) and current rating certified by all

applicable safety agencies

• DC output voltages and current ratings

• Access warning text (“Do not remove this cover. Trained service personnel only. No user serviceable

components inside.”) must be in English, German, Spanish, French, Chinese, and Japanese with
universal warning markings

3.2 Physical Dimensions

The power supply shall be enclosed and meet the physical outline shown in Figure 7, as applicable

24

Figure 7. Mechanical Outline

CFX12V Power Supply Design Guide Rev 1.0

Compact Form Factor with 12-Volt Connector

3.2 Thermal Requirements

3.2.1 Fan and Venting

The fan will draw air from the system enclosure and exhaust the air through a grill located on the back panel.
The CFX12V Power Supply can accommodate up to an 80-mm fan.

The intake and exhaust grills of the power supply shall remain suitably free of obstruction so as not to hinder
airflow. The opening must be sufficiently protected to meet the safety requirements of Section 5. It is
recommended that a flush-mount wire fan grill be used to maximize airflow and minimize acoustic noise.

3.2.2 Airflow and Acoustics

It is recommended but not required that the power supply be designed with an appropriate fan, internal
impedance, and fan speed control circuitry capable of meeting the airflow and acoustic recommendations listed
in Table 15.

Pure Tones: The power supply assembly shall not produce any prominent discrete tone determined according
to ISO 7779, Annex D.

Table 15. Airflow and Acoustic Recommendations

T

PSU_INLET

46°C, sea level Test Condition 1 See Table 16,

50°C, sea level Test Condition 2 See Table 16,

Notes:

(1) Airflow in cubic feet per minute (CFM) through the power supply to be measured per AMCA* Standard 210 (see

8).

(2) The declared sound power level shall be measured according to ISO 7779 for the power supply unit alone (i.e. not in a

system chassis) and reported according to ISO 9296.

DC output load Airflow

≥ 12 CFM ≤ 3.6 BA

Table 17 and Table 18 for
loadings

≥ 18 CFM ≤ 5.2 BA

Table 17 and Table 18 for
loadings

(1)

Declared sound

power, LwAd

(2)

Figure

25

CFX12V Power Supply Design Guide Rev 1.0

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A

A

Compact Form Factor with 12-Volt Connector

Table 16. Loading for Acoustic Test for 220 Watts

Loading condition +12V (A) +5V (A) +3.3V (A) -12V (A) +5Vsb (A) Total Power

Test Condition 1 6.5 3.0 2.0 0.1 1.0 104.6

Test Condition 2 13.0 7.8 6.0 0.2 1.0 219.8

Table 17. Loading for Acoustic Test for 240 Watts

Loading condition +12V (A) +5V (A) +3.3V (A) -12V (A) +5Vsb (A) Total Power

Test Condition 1 7.0 4.0 3.0 0.1 1.0 118.9

Test Condition 2 14.5 8.0 6.4 0.2 1.0 240.1

Table 18. Loading for Acoustic Test for 275 Watts

Loading
condition

Test Condition 1 3.0 5.0 4.5 4.0 0.1 1.0 150.8

Test Condition 2 5.5 10.0 11.0 9.0 0.2 1.0 275.7

+12V1 (A) +12V1 (A) +5V (A) +3.3V (A) -12V (A) +5Vsb (A) Total

(W)

(W)

Power (W)

uxiliary Blower

Rectifying Grid

Nozzle Pressure

uxiliary Blower is controlled to generate a zero Air Pressure

differential. Air Flow is determined from Nozzle pressure.

Nozzle

Power Supply
under Test

ir Pressure

differential.

Figure 8. AMCA* Standard 210

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3.3 Airflow / Fan

The designer’s choice of a power supply cooling solution depends in part on the targeted end-use system
application(s). At a minimum, the power supply design must ensure its own reliable and safe operation.

Fan location/direction: In general, exhausting air from the system chassis enclosure via a power supply fan
is the preferred, most common, and most widely applicable system-level airflow solution.

Fan size/speed: The power supply can accommodate up to an 80 mm axial fan as shown in Figure 7. It is
recommended that a thermally sensitive fan speed control circuit be used to balance system-level thermal and
acoustic performance. The circuit typically senses the temperature of the secondary heat sink and/or incoming
ambient air and adjusts the fan speed as necessary to keep power supply and system component
temperatures within specifications. Both the power supply and system designers should be aware of the
dependencies of the power supply and system temperatures on the control circuit response curve and fan size
and should specify them carefully.

The power supply fan should be turned off when PS_ON# is de-asserted (high). In this state, any remaining
active power supply circuitry must rely only on passive convection for cooling.

Venting: In general, more venting in a power supply case yields reduced airflow impedance and improved
cooling performance. Intake and exhaust vents should be as large, open, and unobstructed as possible so as
not to impede airflow or generate excessive acoustic noise and should meet the safety requirements in section

5. In particular, avoid placing objects within 0.5 inches of the intake or exhaust of the fan itself. A raised wire
fan grill is recommended instead of a stamped metal vent for improved airflow and reduced acoustic noise for
the intake vent.

NOTE:

Venting in inappropriate locations can detrimentally allow airflow to bypass those areas where it is needed.

3.6 AC Connector

The AC input receptacle should be an IEC 320 type or equivalent. In lieu of a dedicated switch, the IEC 320
receptacle may be considered the mains disconnect.

3.7 DC Connectors

Figure 9 shows pin outs and profiles for typical power supply DC harness connectors. The power supply

requires an additional two-pin, power connector.

UL Listed or recognized component appliance wiring material rated min 85 °C, 300 VDC shall be used for all
output wiring.

There are no specific requirements for output wire harness lengths, as these are largely a function of the
intended end-use chassis, motherboard, and peripherals. Ideally, wires should be short to minimize
electrical/airflow impedance and simplify manufacturing, yet they should be long enough to make all necessary
connections without any wire tension (which can cause disconnections during shipping and handling).
Recommended minimum harness lengths for general-use power supplies is 150 mm for all wire harnesses.

27

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Measurements are made from the exit port of the power supply case to the wire side of the first connector on
the harness.

1

+3.3 VDC

+3.3 VDC

+3.3 VDC

+3.3 VDC

COM

COM

+5VDC

+5VDC

COM

COM

+5VDC

+5VDC

COM

COM

PWR_OK

PWR_OK

+5VSB

+5VSB

+12VDC

+12V1DC

+12VDC

+12V1DC

+3.3VDC

+3.3VDC

1

Main Power Connector

Main Power Connector

13

13

+3.3 VDC

+3.3 VDC

- 12VDC

- 12VDC

COM

COM

PS_ON#

PS_ON#

COM

COM

COM

COM

COM

COM

NC

NC

+5VDC

+5VDC

+5VDC

+5VDC

+5VDC

+5VDC

COM

COM

Figure 9. Connectors (Pin-side view, not to scale)

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3.7.1 Main Power Connector

Connector: MOLEX* Housing: 24 Pin Molex Mini-Fit Jr. PN# 39-01-2240 or equivalent

(Mating motherboard connector is Molex 44206-0007 or equivalent)

18 AWG is suggested for all wires except for the +3.3 V supply and sense return wires combined into pin 11
(22 AWG).

Pin Signal Color Pin Signal Color

1 +3.3 VDC

2 +3.3 VDC Orange 14 -12 VDC Blue

3 COM Black 15 COM Black

4 +5 VDC Red 16 PS_ON# Green

5 COM Black 17 COM Black

6 +5 VDC Red 18 COM Black

7 COM Black 19 COM Black

8 PWR_OK Gray 20 Reserved NC

9 +5 VSB Purple 21 +5 VDC Red

10 +12 V1DC Yellow 22 +5 VDC Red

Orange

13

[13]

+3.3 VDC

[+3.3 V default
sense]

Orange

[Brown]

11 +12 V1DC Yellow 23 +5 VDC Red

12 +3.3 VDC Orange 24 COM Black

3.7.2 Peripheral Connector(s)

Connector: AMP* 1-480424-0 or MOLEX 8981-04P or equivalent.

Contacts: AMP 61314-1 or equivalent.

Pin Signal 18 AWG Wire

1 +12 V1DC Yellow

2 COM Black

3 COM Black

4 +5 VDC Red

3.7.3 Floppy Drive Connector

Connector: AMP 171822-4 or equivalent

Pin Signal 20 AWG Wire

1 +5 VDC Red

2 COM Black

3 COM Black

4 +12 V1DC Yellow

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3.7.4 12 V Power Connector

Connector: MOLEX 39-01-2040 or equivalent (Mating motherboard connector is Molex
39-29-9042 or equivalent)

Pin Signal 18 AWG Wire Pin Signal 18 AWG Wire

1 COM Black 3 +12 V2DC Yellow

2 COM Black 4 +12 V2DC Yellow

3.7.5 Serial ATA Power Connector

This is a required connector for systems with Serial ATA* devices.

The detailed requirements for the Serial ATA Power Connector can be found in the “Serial ATA: High Speed
Serialized AT Attachment” specification, Section 6.3 “Cables and connector specification”.

http://www.serialata.org/

Note: connector pin numbers and wire numbers are not 1:1. Carefully check to confirm the correct
arrangement.

Assembly: MOLEX 88751 or equivalent.

Wire Signal 18 AWG Wire

5 +3.3 VDC Orange

4 COM Black

3 +5 VDC Red

2 COM Black

1 +12 VDC Yellow

Figure 10. Serial ATA connector

Wire #s

5
4
3
2

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4 Environmental

The following subsections define recommended environmental specifications and test parameters, based on
the typical conditions the power supply unit may be subjected to during operation or shipment.

4.1 Temperature

Operating ambient: +10 °C to +50 °C (At full load, with a maximum temperature rate of change of 5 °C/10

minutes, but no more than 10 °C/hr.)

Non-operating ambient: -40 °C to +70 °C (Maximum temperature rate of change of 20 °C/hr

4.2 Thermal Shock (Shipping)

Non-operating: -40 °C to +70 °C

15 °C/min
half cycle shall be 30 minutes.

≤ dT/dt ≤ 30 °C/min. Tested for 50 cycles; Duration of exposure to temperature extremes for each

4.3 Relative Humidity

Operating: To 85% relative humidity (non-condensing)

Non-operating: To 95% relative humidity (non-condensing)

Note: 95% RH is achieved with a dry bulb temperature of 55 °C and a wet bulb temperature of 54 °C.

4.4 Altitude Requirement

Operating: To 10,000 ft

Non-operating: To 50,000 ft

.)

4.5 Mechanical Shock

Non-operating: 50 g, trapezoidal input; velocity change ≥ 170 in/s

Three drops on each of six faces are applied to each sample.

4.6 Random Vibration

Non-operating: 0.01 g²/Hz at 5 Hz, sloping to 0.02 g²/Hz at 20 Hz, and maintaining 0.02 g²/Hz from 20 Hz to

500 Hz. The area under the PSD curve is 3.13 gRMS. The duration shall be 10 minutes per axis for all three
axes on all samples.

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4.7 Acoustics

Sound Power: See 3.2.2.

4.8 Ecological Requirements

The following materials must not be used during design and/or manufacturing of this product:

• Cadmium shall not be used in painting or plating.

• Quaternary salt and PCB electrolytic capacitors shall not be used.

• CFC’s or HFC’s shall not be used in the design or manufacturing process.

• Mercury shall not be used.

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5 Safety

The following subsections outline sample product regulations requirements for a typical power supply. Actual
requirements will depend on the design, product end use, target geography, and other variables. Consult your
company’s Product Safety and Regulations department for more details.

5.1 North America

The power supply must be certified by an NRTL (Nationally Recognized Testing Laboratory) for use in the USA
and Canada under the following conditions:

• The supply must be Recognized for use in Information Technology Equipment including Electrical

Business Equipment per
D3 deviations. The certification must include external enclosure testing for the AC receptacle side of the
power supply (see Appendices A, B, C, and D).

• The supply must have a full complement of tests conducted as part of the certification, such as input

current, leakage current, hi-pot, temperature, energy discharge test, transformer output characterization
test (open-circuit voltage, short-circuit current, and maximum VA output), and abnormal testing (to include
stalled-fan tests and voltage-select–switch mismatch).

• The enclosure must meet fire enclosure mechanical test requirements per clauses 2.9.1 and 4.2 of the

above-mentioned standard.

UL 1950 / CAN/CSA C22.2 No. 950-95, renamed UL 60950, 3rd edition, without

100% production HiPot testing must be included and marked as such on the power supply enclosure.

There must not be unusual or difficult conditions of acceptability such as mandatory additional cooling or power
de-rating. The insulation system shall not have temperatures exceeding their rating when tested in the end
product.

The certification mark shall be marked on each power supply.

The power supply must be evaluated for operator-accessible secondary outputs (reinforced insulation) that
meet the requirements for SELV and do not exceed 240 VA under any condition of loading.

The proper polarity between the AC input receptacle and any printed wiring boards connections must be
maintained (that is, brown=line, blue=neutral, and green=earth/chassis).

Failure of any single component in the fan-speed control circuit shall not cause the internal component
temperatures to exceed the abnormal fault condition temperatures per the

IEC 60950 Specification.

5.2 International

The vendor must provide a complete CB* certificate and test report to IEC 60950:1991, 2nd edition + A1, A2,

A3, and A4

include an evaluation summary to

SEC) 207/94.

secondary circuits.

. The CB report must include ALL CB member country national deviations. The CB report must

EN 60950:1992, + A1, A2, A3, A4 and Nordic deviations EMKO-TSE* (74-

All evaluations and certifications must be for reinforced insulation between primary and

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6 System Cooling Considerations

The power supply fan location allows the system designer to utilize the airflow to help cool critical components
such as the processor and chipset. Please note that the fan pulls air from the system, instead of blowing hot
air in, so components must be placed such that airflow is directed across critical components. Cables, etc
must not impede airflow.

For more information on system thermal design, please refer to http://www.formfactors.org/

.

7 Reliability

The de-rating process promotes quality and high reliability. All electronic components should be designed with
conservative device deratings for use in commercial and industrial environments.

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8 Applicable Documents

The following documents support this design guide as additional reference material.

Document Title Description

AB13-94-146

ANSI* C62.41-1991

ANSI C62.45-1992

CSA C22.2 No.234, Level 3

CAN/CSA C22.2 No.950-95,
3rd edition

UL 1950, 3rd edition, without
D3 Deviation

IEC 60950, 2nd ed. 1991: plus
A1, A2, A3, A4

EN 60950, 2nd ed. 1992: plus
A1, A2, A3, A4

EMKO-TSE (74-SEC) 207/94

CISPR 22:1997 3rd edition
EN 55022:1998

ANSI C63.4 – 1992

European Association of Consumer Electronics Manufacturers (EACEM*)
Hazardous Substance List / Certification

IEEE* Recommended Practice on Surge Voltages in Low-Voltage AC Circuits

IEEE Guide on Surge Testing for Equipment Connected to Low-Voltage AC
Power Circuits

Safety of Component Power Supplies (Intended for use with Electronic Data
Processing Equipment and Office Machines)

Safety of Information Technology Equipment Including Electrical Business
Equipment

Safety of Information Technology Equipment Including Electrical Business
Equipment

Safety of Information Technology Equipment Including Business Equipment

Safety of Information Technology Equipment Including Business Equipment

Nordic national requirement in addition to EN 60950

Limits and Methods of Measurements of Radio Interference Characteristics of
Information Technology Equipment, Class B

American National Standard for Methods of Measurement of Radio-Noise
Emissions from Low-Voltage Electrical and Electronic Equipment in the
Range of 9 kHz to 40 GHz for EMI testing

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Document Title Description

AS/NZS 3548 (Class B) Australian Communications Authority, Standard for Electromagnetic

Compatibility* (AU & NZ)

CNS* 13438

Limits and methods of measurement of radio disturbance characteristics of
Information Technology Equipment (Taiwan & China)

EN 55024:1998

Information technology equipment—Immunity characteristics—Limits and
methods of measurement

CISPR 24: 1997

Information technology equipment—Immunity characteristics—Limits and
methods of measurement

EN 61000-3-2

Electromagnetic compatibility (EMC)—Part 3: Limits—Section 2: Limits for
harmonic current emissions, Class D

IEC 61000-4-

Electromagnetic compatibility (EMC) for industrial-process measurement and
control equipment—Part 4: Testing and measurement techniques

Section -2: Electrostatic discharge
Section -3: Radiated, radio-frequency, electromagnetic field
Section -4: Electrical fast transient / burst
Section -5: Surge
Section -6: Conducted disturbances, induced by radio-frequency fields
Section -8: Power frequency magnetic fields
Section -11: Voltage dips, short interruptions, and voltage variations

Japan Electric Association*

Guidelines for the Suppression of Harmonics in Appliances and General Use
Equipment

IEC Publication 417

ISO Standard 7000

CFR 47, Part 15, Subpart B

ICES*-003 (Class B)

VCCI* V-3/99.05 (Class B)

International Graphic Symbol Standard

Graphic Symbols for Use on Equipment

FCC Regulations pertaining to unintentional radiators (USA)

Interference-Causing Equipment Standard, Digital Apparatus (Canada)

Implementation Regulations for Voluntary Control of Radio Interference by
Data processing Equipment and Electronic Office Machines (Japan)

36