EXA40-24S1V8-V - Artesyn Technologies, Inc.

1. Introduction

The EXA40 Series is a new generation of DC/DC converters which

were designed in response to the growing need for low operating

voltage and higher efficiencies. They offer unprecedented efficiency

figures and the greatest range of low output voltages on the market.

In addition the automated manufacture methods and use of planar

magnetics together with an extensive qualification program have

produced one of the most reliable range of converters.

2. Models and Features

The EXA40 comprises eight separate models as shown in Table 1.

All popular integrated circuit operating voltages are covered by the

entire range.

Table 1 - EXA40 Models

Features

• Overtemperature shutdown

• Optional latching OVP

• Primary remote On/Off

• Output voltage adjustability

• Continuous short circuit protection

• Overcurrent limiting

3. General Description

Electrical Description

The EXA40 is a resonant reset Forward converter with synchronous

rectification. A simplified schematic is shown in Figure 1. The

significant gain in efficiency has been achieved by optimum driving

of the synchronous rectifiers.

EXA40 SERIES

Application Note 101 Rev. 01 - Feb. 1999

• Ultra high efficiency topology, 91% typical at 5V

• Operating ambient temperature of -40°C to +70°C (natural

convection)

• Approved to EN60950, UL1950, CSA C22.2 No. 234/950

• Complies with ETS 300 019-1-3/2-3

• Complies with ETS 300 132-2 input voltage and current

requirements

• Fully compliant with ETS 300 386-1

PAGE 1

1. Introduction . . . . . . . . . . . . . . . . . . . . . .1

2. Models and Features . . . . . . . . . . . . . .1

Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1

3. General Description . . . . . . . . . . . . . . .1

Electrical Description . . . . . . . . . . . . . . . . . . . .1

Physical Construction . . . . . . . . . . . . . . . . . . .2

4. Features and Functions . . . . . . . . . . . .2

Overvoltage Protection . . . . . . . . . . . . . . . . . .2

Over Temperature Protection . . . . . . . . . . . . . .3

Current Limit and Short Circuit . . . . . . . . . . . . .3

Remote ON/OFF . . . . . . . . . . . . . . . . . . . . . . .3

Output Voltage Adjustment . . . . . . . . . . . . . . .3

5. Safety . . . . . . . . . . . . . . . . . . . . . . . . . .3

Isolation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3

Input Fusing . . . . . . . . . . . . . . . . . . . . . . . . . . .3

6. EMC . . . . . . . . . . . . . . . . . . . . . . . . . . . .3

Radiated . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4

Conducted . . . . . . . . . . . . . . . . . . . . . . . . . . . .4

7. Use in a Manufacturing Environment . .5

Resistance to Soldering Heat . . . . . . . . . . . . . .5

Water Washing . . . . . . . . . . . . . . . . . . . . . . . . .5

ESD Control . . . . . . . . . . . . . . . . . . . . . . . . . . .5

8. Applications . . . . . . . . . . . . . . . . . . . . .6

Optimum PCB Layout . . . . . . . . . . . . . . . . . . .6

Optimum Thermal Performance . . . . . . . . . . . .6

Remote ON/OFF Control . . . . . . . . . . . . . . . . .7

Output Voltage Adjustment . . . . . . . . . . . . . . .7

9. Appendix 1 . . . . . . . . . . . . . . . . . . . . . .8

Output Voltage Trim Curves . . . . . . . . . . . . . . .9

10. Appendix 2 . . . . . . . . . . . . . . . . . . . . .11

Output TVS Rating . . . . . . . . . . . . . . . . . . . . . 11

11. Appendix 3 . . . . . . . . . . . . . . . . . . . . .13

Recommended PCB Layouts . . . . . . . . . . . . .13

Model Input Voltage Output Voltage

EXA40-24S05 18-36VDC 4.5 to 5.5V

EXA40-24S3V3 18-36VDC 3.0 to 3.6V

EXA40-24S2V75 18-36VDC 2.5 to 3.0V

EXA40-24S1V8 18-36VDC 1.5 to 2.0V

EXA40-48S05 36-75VDC 4.5 to 5.5V

EXA40-48S3V3 36-75VDC 3.0 to 3.6V

EXA40-48S2V75 36-75VDC 2.5 to 3.0V

EXA40-48S1V8 36-75VDC 1.5 to 2.0V

NEW

Product

A separate paper discussing the benefits of “open frame low to

medium DC/DC converters” Design Note 102 is available from

Artesyn Technologies. The effective elimination of potting and a case

has been made possible by the use of modern automated

manufacturing techniques and in particular the 100% use of SMT

components, the use of planar magnetics and the exceptionally high

efficiencies.

4. Features and Functions

Overvoltage Protection

A TVS is used across all models to clamp all transients of short

duration that may occur. The levels of these transients are given in

Table 2.

Table 2 - Output TVS Clamping Voltages

The maximum duration of these pulses and their peak power is

dependent on a number of factors. Appendix 2 contains details of

the output TVS ratings. For a single Pulse the maximum Peak Power

at 1ms is 600W at 25°C (see Figure A2-1). As the ambient

temperature increases so the Peak Pulse power derates as shown in

Figure A2-2.

Repetitive Pulses are not as straightforward and an extra derating

chart is supplied in Figure A2-3. The derating is expressed here as

a function of the pulse duty cycle and pulse width. Note that these

derating factors are quoted at 25°C and must be further derated for

temperature by referring to Figure A2-2.

The OVP function is an optional function that is used to protect the

users circuitry from damage should the converter fail or if an

externally induced transient occurs on the output. The trip points

are set quite accurately at 125% of Vout nominal and are given in

Table 3.

The OVP function has a discrimination circuit to prevent it tripping

due to small duration transients. This filter eliminates any pulses of

between 500µs and 1ms duration over the trip point level.

Table 3 - OVP Trip Point

When the unit trips the PWM controller shuts down the output

within 1ms.

Figure 1 - Simplified Schematic

The DC input is filtered by an LC filter before it reaches the main

transformer. A PWM controller is used to regulate the output. The

main power switch is a MOSFET running at a control frequency of

300KHz.

The output is sensed and compared with a secondary side

reference and an error signal is fed back via an optocoupler to the

PWM controller. The trim pin on the secondary side allows the

output to be adjusted by connecting a resistor between trim and

either the positive or negative output depending on whether you

wish to trim up or down.

The optional latching Over-Voltage Protection (OVP) circuit sends

back a signal to the PWM controller to turn off if the output rises

above a pre-determined limit for longer than 1ms. OVP transients

less than this are eliminated through the use of an output TVS. More

details on the OVP section can be found in the applications section.

The controller latches off until the power is re-cycled or the remote

pin is toggled.

An Over-Temperature Protection (OTP) circuit on the primary side

shuts down the PWM controller if the converter is in danger of being

damaged. Unlike the OVP circuit the OTP circuit does not latch off

the controller. There is however a considerable amount of thermal

hysteresis which is used to protect the unit.

The output synchronous rectifiers are controlled by circuitry on the

secondary side which optimise the driving scheme.

Physical Construction

The EXA40 is constructed using a single multi-layer FR4 PCB. SMT

components are placed on both sides of the PCB and in general,

the heavier power components are mounted on the top side in order

to optimise heat dissipation.

The converter is sold as an open-frame product and no case is

required. The open frame design has several advantages over

encapsulated closed devices. Among these advantages are:

• Cost: No potting compound, case or associated Process costs

involved.

• Thermals: The heat is removed from the heat generating

components without heating more sensitive, less tolerant

components such as opto-couplers.

• Environmental: Some encapsulants are not kind to the

environment and create problems in incinerators. In addition open

frame converters are more easily re-cycled.

• Reliability: Open Frame modules are more reliable for a number

of reasons.

EXA40 SERIES |

Application Note

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Output Voltage TVS Value

5V 6.8V

3.3V 4.0V

2.75V 4.0V

1.8V 4.0V

Input LC

Filter

OTP

PWM Control

OptoCoupler

Feedback &

Adjustability

OVP

Detection

Trim

Synchronous

Rectifiers

On/Off

Output Voltage TVS Value

5V 6.2V

3.3V 4.2V

2.75V 3.6V

1.8V 2.5V

5. Safety

Isolation

The EXA40 has been submitted to independent safety agencies and

has EN60950 and UL1950 Safety approvals. Basic insulation is

provided and the unit is approved for use between the classes of

circuits listed in Table 4.

Table 4 Insulation categories for Basic

The TNV or Telecommunication Voltage definitions are given in Table

V.1 of IEC950 from which EN60950 and UL1950 are derived.

The EXA40 has an approved insulation system that satisfies the

requirements of the safety standards.

In order for the user to maintain the insulation requirements of these

safety standards it is necessary for the required creepage and

clearance distances to be maintained between the input and output.

Creepage is the distance along a surface such as a PCB and for the

EXA40 the creepage requirement between primary and secondary is

1.4mm or 55 thou. Clearance is the distance through air and the

requirement is 0.7mm or 27 thou.

Input Fusing

In order to comply with safety requirements the user must provide a

fuse in the unearthed input line if an earthed input is used. The

reason for putting the fuse in the unearthed line is to avoid earth

being disconnected in the event of a failure. If an earthed input is

not being used then the fuse may be in either input line.

For the 48V input models a 2A Anti-Surge Fuse should be used and

for the 24V models a 3.15A Anti-Surge fuse is required. High

Rupture Capacity (HRC) fuses are recommended.

6. EMC

The EXA40 has been designed to comply with the EMC

requirements of ETSI 300-386-1. It meets the most stringent

requirements of Table 5; Public telecommunications equipment,

locations other than telecommunication centres, High Priority of

Service. Following is the list of standards which apply and which it

has complied with.

Over Temperature Protection

This feature is included as standard in order to protect the converter

and the circuitry it powers from overheating in the event of a

runaway thermal condition such as a fan failure at high

temperatures. or continuous operation above Tmax at full power.

The actual ambient temperature it trips at is dependent on quite a

number of factors The airflow over the unit is the most dominant

parameter. The trip point is also affected by the input voltage,

output trim voltage, user PCB layout, output load and model.

For all models under full load conditions the trip point will be at a

minimum of 75°C in still air using the recommended layout in the

Applications section. Still Air or natural convection is defined as

0.1m/s airflow.

As the load is decreased and the unit is operated at higher

temperatures, the trip point also rises. This trip point will at all times

protect the unit and will be a minimum of 5°C away from the safe

operating temperature of the device.

Current Limit and Short Circuit

All models of the EXA40 have a built in current limit function and full

continuous short circuit protection.

The current limit inception point is dependent on the input voltage,

ambient temperature and has a parametric spread also. For all

models the inception point is typically 140% or 11.2A. It may go as

high as 180% or as low as 100% over all operating conditions and

the lifetime of the product.

None of the specifications are guaranteed when the unit is operated

in an overcurrent condition. The unit will not be damaged in an

overcurrent condition as it will protect itself through the use of the

OTP function before any damage occurs. However the lifetime of

the unit will be reduced.

In short circuit the unit enters a ‘hiccup’ foldback current mode and

may be operated continuously in this condition. The duty cycle of

this hiccup is dependent on input voltage, temperature etc. The

RMS value of the short circuit current is guaranteed to be a

maximum of 12A RMS over all operating conditions and the lifetime

of the product. While the unit is specified to operate into a

continuous short circuit, extended or frequent short circuits will

reduce the lifetime of the converter.

A short circuit is defined as a resistance of 20mΩor less.

Remote On/Off

The remote On/Off function allows the unit to be controlled by an

external signal which puts the module into a low power dissipating

sleep mode. Methods of applying are given in the applications

section.

Output Voltage Adjustment

The output voltage on all models except for the 1.8V output is

trimmable by ±10%. The 1.8V output is asymmetrically trimmable

by +13% and -18%. Details on how to do trim all models are

provided in the applications section.

PAGE 3

EXA40 SERIES |

Application Note

Insulation

Between And

TNV-1 Circuit Earthed SELV Circuit

Unearthed SELV Circuit

TNV-2 Circuit Earthed SELV Circuit

TNV-3 Circuit Unearthed SELV Circuit or or

TNV-1 Circuit

Earthed or Unearthed Earthed SELV Circuit

Hazardous Voltage ELV Circuit

Secondary Circuit Unearthed Hazardous

Voltage Secondary Circuit

TNV-1 Circuit

Conducted emissions

The required standard for conducted is EN55022 Class A (FCC Part

15). The EXA40 has quite a substantial LC filter on board to enable

it to meet this standard with just the addition of one external

component for the 48V models and two for some of the 24V

models.

The conducted noise graphs for the EXA40-48S05 are given in

Figure 2 & Figure 3 . The graphs of all other models are available on

request.

Figure 2 - EXA40-48S05 Class A Conducted Noise

Figure 3 - EXA40-48S05 Class B Conducted Noise

The required Filters to meet Class A & Class B for all models shown

in Figure 4 to Figure 7. Table 7 is a cross-reference which indicates

which filter is required for which model.

Radiated emissions

The applicable standard is EN55022 Class B (FCC Part 15). Testing

DC/DC converters as a stand-alone component to the exact

requirements of EN55022 (FCC Part 15) is very difficult to do as the

standard calls for 1m leads to be attached to the input and output

ports and aligned such as to maximise the disturbance. In such a

set-up it is possible to from a perfect dipole antenna that very few

DC/DC converters could pass.

However the standard also states that ‘An attempt should be made

to maximise the disturbance consistent with the typical application

by varying the configuration of the test sample’. In addition ETS 300

386-1 states that the testing should be carried out on the enclosure.

The EXA40 is primarily intended for PCB mounting in

Telecommunication Rack systems.

For the purpose of the radiated test the unit was mounted on a 6U

high PCB with a 40W load on board and connections to the remote

on/off and trim pins. The recommended PCB layouts were used on

the test PCB. The unit was then mounted in an ETSI standard 19”

rack system and the position of the card was varied to achieve

maximum emissions.

There was a 4µF capacitor connected across the input and the

ground plane was connected to the output (pin 7). However the

difference between the ground plane being connected to the input

or output is minimal. Details of the capacitor and optimum

groundplane can be found in later sections.

The test results for the 48S05 and 24S05 models are shown in

tables 5 and 6 below as these are the models with the highest

switching voltages and currents. The testing was carried out by an

independent test house and a copy of the report is available on

request.

Table 5 - Radiated Emissions on EXA40-48S05

Table 6 - Radiated Emissions on EXA40-24S05

In both cases the unit passed the Class B limit which is 30 dBV/m

with a significant margin.

Frequency (MHz) Response (dBµV/m)

30.00 14.80

102.53 23.75

108.50 21.80

109.09 22.85

110.67 23.00

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EXA40 SERIES |

Application Note

Frequency (MHz) Response (dBµV/m)

30.00 14.80

108.56 15.80

108.81 16.85

110.62 19.00

111.50 21.20

Table 7 - Model/Filter cross-reference

Figure 4 - Filter A

Figure 5 - Filter B

Figure 6 - Filter C

Figure 7 - Filter D

The part numbers of the parts used in each case are

given below.

Film Capacitor ITW Paktron part number 405K100CS4G.

Surface Mount Ferrite Bead part no; MMG DS52-9K3F-R1ES2.

24Vin models use 10µH TDK inductor part no; SLF10145T-

100M2R5.

48Vin models use 47µH TDK inductor part no; SLF10145T-

470M1R4.

7. Use in a Manufacturing Environment

Resistance to Soldering Heat

The EXA40 is intended for PCB mounting. Artesyn has determined

how well it can resist the temperatures associated with the soldering

of PTH components without affecting its performance or reliability.

The method used to verify this is MIL-STD-202 method 210D.

Within this method two test conditions were specified, Soldering

Iron condition A and Wave Solder condition C.

For the soldering iron test the UUT was placed on a PCB with the

recommended PCB layout pattern shown in the applications

section. A soldering iron set to 350°C ± 10°C was applied to each

terminal for 5 seconds. The UUT was then removed from the test

PCB and was examined under a microscope for any reflow of the

pin solder or physical change to the terminations. None was found.

For the wave soldering test the UUT was again mounted on a test

PCB. The unit was wave soldered using the conditions shown in

Table 8.

Table 8 Wave Solder Test Conditions

The UUT was inspected after soldering and no physical change on

pin terminations was found.

Water Washing

The EXA40 is suitable for water washing as it doesn’t have any

pockets where water may congregate long-term. The user should

ensure that a sufficient drying process and period is available to

remove the water from the unit after washing

ESD Control

The EXA40’s are manufactured in an ESD controlled environment

and supplied in conductive packaging to prevent ESD damage

occurring before or during shipping. It is essential that they are

unpacked and handled using an approved ESD control procedures.

Failure to do so could affect the lifetime of the converter.

EXA40 SERIES |

Application Note

PAGE 5

Temperature Time Temperature Ramp

260°C ±5°C 10s±1 Preheat 4°C/s to 160°C.

25mm/s rate

E.U.T.

2 x 4µF Film Caps

+ Vin

- Vin

E.U.T.

2 x 4µF Film Caps

+ Vin

- Vin

Inductor Dependent on Input Voltage

E.U.T.

2 x 4µF Film Caps

+ Vin

- Vin

Inductor dependent on Input Voltage

SM Ferrite

2 x 4µF Film Caps

+ Vin

- Vin

Inductor dependent on Input Voltage

SM Ferrite

Model Class A Class B

48S1V8 Filter A Filter C

48S2V75 Filter A Filter C

48S3V3 Filter A Filter C

48S05 Filter A Filter B

24S1V8 Filter A Filter C

24S2V75 Filter B Filter C

24S3V3 Filter B Filter C

24S05 Filter B Filter D

8. Applications

Optimum PCB Layout

The recommended PCB layout for a double and single sided PCB’s

are given in Appendix 3. At a minimum 2oz/ft2or 70µm copper

should be used. The PCB acts as a heatsink and draws heat from

the unit via conduction through the pins and radiation. The two

layers also act as EMC shields.

If 2oz/ft2copper or the recommended layout isn’t used then the user

needs to ensure that the unit always operates within correct

temperature limits by measuring the hotspots indicated in the

thermal section.

For a double-sided PCB Figure A3-1 and Figure A3-2 should be

used Figure A3-4 should be used for single-sided PCB’s. Figure

A3-5 show locations where via should not be placed on the user

application to avoid solder mounds causing isolation problems.

Optimum Thermal Performance

All models of the EXA40 except the EXA40-24S05 can operate in

still air up to a maximum ambient temperature of 70°C using the

recommended PCB layout shown in the previous section. The

EXA40-24S05 is limited to 60°C without airflow. Still air which is

sometimes called natural convection is defined as 0.1m/s airflow.

Above 70°C the output power may be derated so that the maximum

ambient operating temperature can be extended to 100°C as shown

in Figure 8 and Figure 9.

Figure 8 - Output Power versus Ambient Temperature

in natural Convection

Figure 9 - Output Power versus Ambient Temperature

in natural Convection for the EXA40-24S05

120%

100%

80%

60%

40%

20%

0 20 40 60 80 100-40 -20

If forced air cooling is used then the converter may be used up to

95°C at full output power dependent on the airflow. Figure 10 is a

graph of the maximum allowed ambient temperature at full power

versus the airflow across the converter.

Figure 10 - Max. Ambient Temperature at full

Power with Forced Airflow

If the unit is operated with forced airflow then it may be operated to

100°C with linear derating from the maximum ambient specified in

Figure 10. Figure 11 shows the derating for a converter operating

with 1.5m/s forc

ed airflow for all models except the EXA40-24S05.

Figure 11 - Thermal Derating for 1.5m/s Forced Airflow.

Figure 12 shows the derating for an EXA40-24S05

Figure 12 - Thermal Derating for 1.5m/s Forced Airflow.

EXA40 SERIES |

Application Note

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120%

100%

80%

60%

40%

20%

0 20 40 60 80 90 100-40 -20

120%

100%

80%

60%

40%

20%

OUTPUT POWER

020406078100

Maximum Ambient (°C)

120%

100%

80%

60%

40%

20%

OUTPUT POWER

02040608088100

Maximum Ambient (°C)

100

0 0.5 1.0 1.5 2.0

Airflow (m/s)

Max. Ambient (°C)

Max. Ambient

24S05 Only

EXA40 SERIES |

Application Note

PAGE 7

The most accurate method of ensuring that the converter is

operating within its guidelines in a chosen application is to measure

the temperature of a hot-spot. There are three such spots on the

EXA40 and which is the hottest is dependent on the input line

voltage, output load and the ambient temperature. In general they

will be within 10°C of each other.

These hot spots are shown in Figure 13. They are the main primary

switch and the two secondary synchronous rectifiers, each of which

is a D2PAK.

Figure 13 Hot Spot Locations

When measuring the temperature of these points the thermocouple

should be mounted as closely as possible to the tab of the device.

In order to maintain the Artesyn Derating criteria the temperatures of

the devices should never exceed 120°C.

Remote On/Off Control

The remote On/Off control is a primary referenced function which

allows the converter to be put into a low power dissipating sleep

mode. The maximum current taken by unit during this mode is 2mA

over all line and temperature conditions.

The remote On/Off pin can source typically 70µA of current into the

collector of a transistor and can be directly connected to an

optocoupler open collector output. The following three figures

provide details of methods of connecting to the remote on/off pin.

Figure 14 Implementation of Remote On/Off

with a single Transistor

Figure 15 Implementation of Remote On/Off

with TTL Devices

Figure 16 Secondary Side control of Remote On/Off

Output Voltage Adjust

The output voltage can be adjusted by connecting a resistor

between the output trim pin and either the output high or low pin.

For the 2.75V, 3.3V and 5V outputs the trim function has a range of

approximately ±10%. For the 1.8V output the trim range is typically

+13%/-18%. The following three figures show how the output may

be trimmed either high or low while Appendix 1 contains graphs

which plot the output voltage against the trim resistor for all models.

Figure 17 Output Trim Low using a Fixed

resistor or Potentiometer

Input +

Input -

Remote On/Off

Input +

Input -

Remote On/Off

74LSO1

Other Suitable Devices:

74LS15 74LS03

74LS26 74LS12

74LS22 74LS136

74LS266

Output +

Output -

Remote

On/Off

Input +

Input -

Trim

Secondary

Side

Control

Circuitry

Output +

Output -

Trim

Hot Spots

EXA40 SERIES |

Application Note

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Figure 18 Output Trim High using a Fixed

resistor or Potentiometer

Figure 19 Variable Output Trim using a Potentiometer

Output +

Output -

Trim

Output +

Output -

Trim

Appendix 1 Output Voltage Trim Curves

EXA40 SERIES |

Application Note

PAGE 9

2.1

2.0

1.9

1.8

1.7

1.6

1.5

1.4

0 1000 2000 3000 4000 5000 6000 7000 8000 9000 10000

3.1

3.0

2.9

2.8

2.7

2.6

2.5

2.4

0 4000 8000 12000 16000 20000 24000 28000 32000 36000 40000

Figure A1-1 - 1.8V Output Voltage vs. Trim Resistor Value

Figure A1-2 - 2.75V Output Voltage vs. Trim Resistor Value

EXA40 SERIES |

Application Note

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Appendix 1 Output Voltage Trim Curves

3.8

3.7

3.6

3.5

3.4

3.3

3.2

3.1

3.0

2.9

0 4000 8000 12000 16000 20000

5.6

5.4

5.2

5.0

4.8

4.6

4.4

0 8000 16000 24000 32000 40000 48000 56000

Figure A1-3 - 3.3V Output Voltage vs. Trim Resistor Value

Figure A1-4 - 5V Output Voltage vs. Trim Resistor Value

Appendix 2 Output TVS Rating

EXA40 SERIES |

Application Note

PAGE 11

100

0.1

0.1 1 10 100 1,000 10,000

Pulse Width, Tp (µs)

Peak Power, Pp (kW)

120%

100%

80%

60%

40%

20%

0255075100

Ambient Temperature (°C)

Peak Pulse Derating (%)

Figure A2-1 - TVS Output Rating vs. Pulse Width @ 25˚C Ambient

Figure A2-2 - Output TVS Peak Pulse Derating vs. Ambient Temperature

EXA40 SERIES |

Application Note

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Appendix 2 Output TVS Rating

1.00

0.10

0.01

0.1 0.2 0.5 1 2 5 10 20 50 100

Duty Cycle (%)

Derating Factor

10ms

1ms

100us

10us

Pulse Width

Remote

On/Off

+Vin

Trim

+Vout

2.20

(55.88) 0.08 (2.00)

Isolation

2.20

(55.88)

VIEW IS FROM TOP SIDE

TOP SIDE LAYER 1 OF 2

ALL DIMENSIONS IN INCHES (mm)

ALL TOLERANCES ARE ±0.10 (0.004)

THERMAL RELIEF IN CONDUCTOR PLANES

REFERENCE IPC-D-275 SECTION 5.3.2.3

Figure A2-3 3.3V Output Voltage vs. Trim Resistor Value

Figure A3-1 - Recommended Top

Layer Footprint Figure A3-2 - Recommended Bottom

Layer Footprint Figure A3-3 - Recommended Single

Sided PCB Layout

Appendix 3 Recommended PCB Layouts

-Vin -Vout

2.20

(55.88) 0.08 (2.00)

Isolation

2.20

(55.88)

VIEW IS FROM TOP SIDE

BOTTOM SIDE LAYER 2 OF 2

ALL DIMENSIONS IN INCHES (mm)

ALL TOLERANCES ARE ±0.10 (0.004)

THERMAL RELIEF IN CONDUCTOR PLANES

REFERENCE IPC-D-275 SECTION 5.3.2.3

Remote

On/Off

+Vin

Trim

+Vout

2.20

(55.88) 0.08 (2.00)

Isolation

2.20

(55.88)

VIEW IS FROM TOP SIDE

BOTTOM SIDE LAYER 1 OF 1

ALL DIMENSIONS IN INCHES (mm)

ALL TOLERANCES ARE ±0.10 (0.004)

THERMAL RELIEF IN CONDUCTOR PLANES

REFERENCE IPC-D-275 SECTION 5.3.2.3

-Vout

-Vin

0.04

(1.00)

2 Places

0.25

(6.35)

0.90

(22.86)

1.02

(25.92)

1.26

(32.00)1.57

(40.01)

2.00

(50.80) 2.13

(54.07)

Typ.

0.08

(2.00)

Typ.

0.10

(2.50)

Typ.

2.20

(55.88)

1.21

(30.83)

0.92

(23.48)

0.88

(22.46)

ø0.12

(ø3.00)

4 Places

0.78

(19.80)

0.98

(24.90)

1.22

(30.98)

2.10

(53.39)

Typ.

2.20

(55.88)

2.09

(53.14)

1.91

(48.46)

ALL DIMENSIONS IN INCHES (mm)

ALL TOLERANCES ARE ±0.10 (0.004)

ROUTE VIA HOLES AWAY

FROM SHADED AREAS

EXA40 SERIES |

Application Note

PAGE 13

Figure A3-4 Footprint Via Keep-out Areas

Appendix 3 Recommended PCB Layouts

PAGE 14

http://www.artesyn.com

AN_EXA40_19990209_PRE.PDF

2000

The information and specifications contained in this data sheet are believed to be correct at time of publication. However, Artesyn Technologies accepts no responsibility for consequences arising

from printing errors or inaccuracies. Specifications are subject to change without notice. No rights under any patent accompany the sale of any such product(s) or information contained herein.