The product standard only contains minimum requirements. Attention is drawn to the fact that appliance specifications might contain requirements additional to or deviating from those specified in the relevant product standards.

Please be aware that the specifications nominal value used in the German part of the Schurter catalogue and the data sheets, is synonymous with rated value.

The difference between these two values is a pure matter of definition. In order to avoid any unnecessary complications we will continue to use the specifications nominal value.

CE marking is the only marking which indicates that a product conforms to the relevant EU-directive.

This means that the CE-mark is no quality or standard conformity mark but only an administration mark.

SCHURTER products are covered by the low voltage directives 72/23/EEC and 93/68/EEC. Those are valid for equipment and appliances with rated voltage values between AC 50 V to AC 1000 V as well as DC 75 V to DC 1500 V.

The CE marking of SCHURTER parts will be found on the label of the smallest packing unit. On request we will submitt a CE conformity statement for each component. CE conformity statements and approvals can also be retrieved from the internet under www.schurter.com.

National testing institutions are testing according to national and international standards or other generally recognized rules of technology. Their certification/approval-marks confirm the observance of the safety requirements which electric appliances must fulfil.

Approvals

National approvals

In addition to the combined UL/CSA approvals, most of the SCHURTER components are also approved by one of the European certification bodies like VDE (Germany), Electrosuisse (Switzerland) or SEMKO (Sweden). The safety testing of all these European certification bodies are based on the commen European safety standards. With the harmonisation effort in Europe, the different national European certification bodies have lost their importance and SCHURTER has decided to maintain only one European approval (e.g. VDE, SEV or SEMKO) in future. The others will not be renewed once they have expired.

Because UL and CSA are not members of the CENELEC, the standards of UL and CSA are not harmonised yet with the European standards. However, UL and CSA are trying to harmonize their standards with each other. Where possible, SCHURTER will apply for the combined cULus or cURus approval.

Further to development in Asia, SCHURTER has obtained national approvals from China, Japan and Korea.

Information about approvals

SCHURTER products are certified according to EN / IEC standards and carry country specific approvals in Europe.

During the last few years European countries made much effort to reduce their approval marks to one generally accepted mark. The ENEC approval mark replaces (wherever possible) the previous approval mark. The ENEC mark is offered by all national certification bodies that signed for the European certification agreement (CCA)*.

SCHURTER decided to reduce the variety of European approval marks. For new approbations of SCHURTER parts only the ENEC will be mentioned in the future:

Approvals for the US and Canada are according to the UL and CSA standards:

As UL and CSA are not a member of CENELEC these two are not according to the European approval marks. Wherever possible SCHURTER want to acquire the combined cULus approval mark:

Since Aug. 1^st. 2003 the Chinese approval mark is required for a lot of products to import to China. SCHURTER strives to get the approvals for the concerned products. For not testable products we offer an import certificate (free of CCC).

Further information:

http://www.enec.com

Approval Industry Links

* members of ENEC agreement:

Standards IEC 60529; EN 60529 and DIN 40050

Scope

These standards apply to the classification of degrees of protection provided by enclosures for electrical equipment with a rated voltage not exceeding 72.5 kV.

Object

The object of these standards is to give:

a) Definitions for degrees of protection provided by enclosures of electrical equipment as regards:

1. Protection of persons against access to hazardous parts inside the enclosure

2. Protection of the equipment inside the enclosure against ingress of solid foreign objects

3. Protection of the equipment inside the enclosure against harmful effects due to the ingress of water.

b) Designations for these degrees of protection.

c) Requirements for each designation.

d) Tests to be performed to verify that the enclosure meets the requirements of these standards.

Designations

The degree of protection provided by an enclosure is indicated by the IP code.

Elements of the IP code and their meanings

A brief description of the IP code elements is given in the following table.

1. Protection against direct and indirect contact – general terms

The protection against electric shock on electric equipment as well as their components are divided into the following parts:

¹⁾ Accessible, conductive part, which is not conductive normally but which may be conductive due to a failure.

2. Protection against direct contact with live parts e.g. of a fuseholder

The data sheets of the relevant components inform about the taken measures.

3. Protection against indirect contact

Measures for the protection against indirect contact on electrical equipment are defined according to IEC 61140 by the 4 protection classes 0, I, II, III. Each protection class includes two protection measures. Even if one of these measures should fail, no electric shocks will occur.

Same requirements are valid for filters as for RF suppression chokes.

Frequency range 0.01 MHz ... 1000 MHz

Electromagnetic compatibility (EMC) is the capability of electrical equipment (installations, devices, assemblies) to operate effectively in its electromagnetic environment (Immunity), without in turn irresponsibly affecting this environment (Emission).

Mains filters of various types are used for the protection of electronic circuits, components and equipment against transients or similar interference, on the mains power supply. A suitable filter can be selected from the existing product range for each equipment type in accordance with electromagnetic conditions of its environment.

Mains interference can be classified into four categories:

In practice, however, interference is mainly found in the last three categories B, C and D. Superimposed on the high-voltage mains supply, such interference can affect the performance of electronic circuits, or even cause them damage. An optimally-designed mains filter can perform a double function:

Function 1

The filter protects an electronic control circuit from voltage spikes in the mains supply, which may be generated, for example, by electromechanical switches and relays.

Function 2

The same filter also acts simultaneously in the opposite direction. The HF interference generated in the unit by thyristor control is attenuated such that the boundary values Class B, (EN 55011/55022) are maintained.

Filters are usually made up of capacitors and inductance coils. Components such as leakage resistors, surge dissipators and VHF chokes can also be integrated into the filter. Broad band filters

which meet the highest requirements are often composed of 2 or 3 single stages put together to make one filter unit:

Leakage current according to IEC 60335-1

The leakage current of a device is mainly determined by the capacity value of the Y-capacitor.

According to international standards (IEC 60335-1) the following regulations with respect to leakage current can be assumed:

Rated voltage UR (U_max)

The rated voltage UR is the maximum RMS alternating line to line voltage (U_max) which may be applied continuosly to the terminals of the filter. The rated voltage is the nominal voltage including 10% tolerances.

Example:

Filter with U_R = 440 VAC is made for a power system with nominal voltage 400 VAC +10%.

For standard three phase filters the voltage between phase and earth is intended U_R/√3 (example 440/250 VAC).

Filters made for IT power systems withstand a voltage between phase and earth equal to U_R.

SCHURTER filters for IT systems have code endingwith „I“: ex. FMAC-0932-2512I.

The line frequency f_N (50/60 Hz) may be exceeded under certain conditions. We recommend the users to consult in any case our technical department. DC power operation is possible in most cases.

Power distribution system

There are three main types of power distribution systems according to IEC 60950 (1.2.12): TN, TT, IT.

The TN POWER SYSTEM is a power distribution system having one point directly earthed, the exposed conductive parts of the installation being connected to that point by protective earth conductors. Three types of TN POWER SYSTEMS are recognized according to the arrangement of neutral and protective earth conductors: TN-S, TN-C-S, TN-C.

Example of a TN-C-S system

TN-C-S is in a system which neutral and protective functions are combined in a single conductors in a part of the system.

Example of a TT system

A TT POWER SYSTEM is a power distribution system having one point directly earthed, the exposed conductive parts of the installation being connected to earth electrodes electrically indipendent of the earth electrodes of the power system.

Example of a IT system

The IT POWER SYSTEM is a power distribution system having no direct connection to earth, the exposed conductive parts of the electrical installation being earthed. In this case the voltage between phase and earth can reach the line to line voltage.

Nominal Current I_N

The technical data gives the max continuous supply current in function of the ambient temperature I_N/νa. The SCHURTER range generally differentiates between two types of filters:

The permissible working current at higher ambient temperatures can be read from the following graph.

Permissible working current as a function of ambient temperature

Up to the approved nominal ambient temperature a the filter can be operated continuously at its nominal current. Above this temperature the square of the nominal current drops off linearly and reaches its zero point at Tmax (85 or 100 °C).

Derating curve (approx.)

Formula:

Leakage current

(see also chapter RF suppression capacitors: General information) 1-Phase measuring techniques

Measurement of the leakage current (simplified).

The leakage current is measured from every pole of the network:

The test is made with AC at 250 V / 50 Hz.

Measurements are made in both switch positions (see diagram).

Protection class l

Devices are fitted with a special grounding conductor to provide protection against electrical shocks (L,N,PE wire cable). SCHURTER filters correspond to protection class I.

Insertion loss acc. CISPR 17 (common- and differential mode)

Asymmetrical measurement

In common mode measurements, the line and neutral conductors are measured with respect to earth.

Line (L) and neutral (N) are measured to earth (E).

Symmetrical measurement

In differential mode measurements, the insertion transmission loss is measured between line and neutral through a balancing transformer; the earth wire is not used.

4-pole network with integrated balancing transformer for the measurement of insertion transmission loss in the symmetric case.

Measurement method

The insertion loss D is defined as that loss which results when a four-pole network is inserted into an existing layout, having a surge impedance Z, assuming that the LHS and the RHS terminal impedances of the four-pole network are equal in magnitude and real, the insertion transmission loss and the overall loss are the same.

The insertion transmission loss, in decibels, can be obtained as follows:

Insertion loss “alternate test method�?

Asymmetrical measurement

Symmetrical measurement

The alternate test method allows the measurement in the GHz frequency range whereas the CISPR 17 method does not cover frequencies above 30MHz. The insertion loss is measured in a throughput method (common mode) and a cross coupled method (differential mode). The differential mode measurement of the alternate test method is not directly comparable to the conventional measurement acc. CISPR 17.

In compliance to the known standards of the IEC, EN, VDE and UL, the filters are tested as follows. In principle, these tests correspond to those of the RF suppression capacitors.

Test duration

- 2 sec for production test

- 60 sec for types test

The SCHURTER final production test has a duration of 2 sec. This test may not be repeated more than one time (i.e. incoming inspection at the customer). Any filter that has been under test for 60 sec can not be commercially used (reduced life cycle).

The aim of this standard is to create a basis for classification of telecommunication engineering electrical components according to application classes which correspond to their climatic and mechanical suitability.

Example:

* relative humidity

The high reliability of the filters can be excelled from MTBF (meantime between failures). These values are according MIL-HB-217-F class G_B at an amient temperatur 40§C at rated voltage and current.

1st stage

A differential mode acting filter with high energy absorption. Discharging resistors are normally used for Cx capacitors > 100 nF. The capacitors are tested and approved as so-called class X noise suppression capacitors. The 1st stage serves as dl/dt limitation.

2nd stage

A common mode acting filter with a high, broad band attenuation ratio. A ZNR varistor surge serves as the overvoltage suppression component. The earthed capacitors are tested and approved as so-called class Y noise suppression capacitors.

3rd stage

Common mode as well as differential mode acting filter in the HF range up to 300 MHz. Feedthrough capacitors make high attenuation values possible up to the gigahertz range. These capacitors are also class Y type. SCHURTER uses only approved noise suppression capacitors according to EN 132400.

Three types of mains noise suppression filter assemblies are used in practice:

Collective suppressor

The collective suppressor principle results in one filter per plant. This has to cope with the entire power input. In addition, all of the connecting cables have to be shielded. Furthermore interference generated by «A» device can reach other devices for instance «B» or «C» through the connecting cables. The following example promises to be a more economical solution. In many cases, the single suppressor principle is the most economical

solution.

Single suppressors

Combined single and collective suppressor

From the technical point of view, only the combined application of both suppression techniques can result in a significant improvement.

In the field of interference and RF suppression, the most significant means of transmission is the direct electrical connection, i.e. the connecting wiring. The radiation coupling is also important from the electromagnetic compatibility (EMC) point of view; it cannot, however, be dealt with here.

Interference propagation

The capacitive and inductive coupling effects occur inside the case. These could be:

The introduction briefly mentioned the possibility of the mains filter operating with a double function. Depending on the main area of application, these filters are designated as either RF SUPPRESSION FILTERS or INTERFERENCE SUPPRESSION FILTERS.

The one filter may, therefore, appear under two references in the documentation. A filter is also classified by its mechanical design as well as its electrical data.

RF SUPPRESSION FILTERS impede the propagation of RF interference, generated by an electronic or electrical device into the mains. They also ensure an interference-free radio reception in the immediate vicinity.

INTERFERENCE SUPPRESSION FILTERS prevent mains interference from affecting electronic equipment. They enable an interference- free operation even in the case of a power supply badly affected by mains interference.

It is common to operate the mains filter in both directions in the one piece of equipment, allowing it to fulfil its double function as both interference and RF suppression filters as specified.

Filter engineering differentiates between common and differential mode interference originating from supply lines.

In the case of a non-earthed interference source, interference at first only propagates along the connecting lines. Like the mains AC current, the parasitic current flows to the user on one lead, and returns to the interference source on the other. Both these currents are in differential mode. This type of interference is therefore referred to as differential mode interference.

Due to the mechanical configuration and its parasitic capacitance, parasitic currents are also generated in the earthing circuit. This parasitic current flows on both connecting leads to the user and over an earthed lead back to the interference source. Both currents on the connecting lead are in common mode. This type of interference is therefore referred to as common mode interference.

For easy reading of the catalogue data, SCHURTER uses the following simplified filter classification:

Medical filter

SCHURTER medical filters comply with UL544 and IEC 60601-1 standard specifications and are available in two versions, which differ in terms of their leakage current values.

Medical filter (M5)

1) Line

2) Load

Medical filter (M80)

1) Line

2) Load

Standard medical filters for direct person contact supplied by SCHURTER have a leakage current value of <5 μA (M5). This can only be achieved without C_y. Here, a common mode fault current against earth is not attenuated and the filter acts only on differential mode fault currents. In addition, an inlet in protection class II can be used here, as no earth connection exists. However, if an earth connection is desired, Type (M80) can be used for indirect person contact; this has a leakage current of <80 μA which is below the required limit value of 0.1 mA. Type (M80) is manufactured to special order.

Bleed resistor

Medical filters and filters with a X-capacitor >100 nF have a bleed resistor so that no inadmissible rest voltage occurs at the touchable pins of the inlet.

All SCHURTER filters are fitted with chokes which satisfy the guidelines set down by international and national standards organizations.

The most important test data for RF suppression chokes are:

Maximum variation

Insulation resistance R_is: 6000 MΩ

Temperature rise at nominal current: ΔT = 60°C

Short-circuit strength:

EN and VDE: not applicable

SEV→: 25 x I_N (2 half-waves)

The main type of choke used in suppression filter engineering is the current compensated choke. This mainly damps the common mode interference. The differential mode parasitic current, or rather the magnetic flux they produce in the core, is compensated by means of a special type of winding. The relatively small attenuation of the differential mode parasitic currents can be balanced through the large, symmetrically connected capacitance C_x between the lines. Only the leakage inductance L_s of the choke is then of any importance.

The high nominal inductance LN active for common mode parasitic currents allows the insertion of small, earthed capacitances CY in a filter circuit. These capacitances are regulated by international standards for leakage currents.

All SCHURTER filters are fitted with class X or Y RF suppression capacitors in accordance with international standards (IEC, EN). These are mainly self-healing metallized paper or polyester types, tested against the standards of major countries around the world and approved as noise suppression capacitors. Class X capacitors are capacitors with unlimited capacity for those applications in which a failure caused by a short circuit cannot result in a dangerous electrical shock. Class Y capacitors are capacitors intended for an operating voltage U_eff = 250 V with increased electrical and mechanical safety and limited capacitance.

All SCHURTER filters are equipped with components which have been tested and approved as R_F suppression capacitors.

The most important test data for R_F suppression capacitors are:

Capacitance C_x, C_y ± 20% for fM = 1 kHz

Insulation resistance Ris between the capacitor terminals:

for C > 0.33 μF: R_is x C > 2000 s (time constant)

for C 0.33 μF: R_is> 6000 MOhm

X2Y^® filter combines the X and Y capacitors into a component that is in contact with the filter enclosure over a broad surface. The leads connecting the capacitors are thereby eliminated and parasitic impedances are reduced to a minimum. This results in broadband suppression into high frequency ranges.

The most important safety standards for equipment/installations are listed in the following:

There are basically 2 types of emitted disturbances: conducted and radiated. Line interferences are high frequency noise signals which are superimposed on the useful signals on input and output lines. Interference signals can be of common- or differential mode type. The significance of line interference is reduced dramatically above a frequency of 30 MHz. From here radiated interference increases greatly. On the following pages we will nevertheless deal with conducted interference only.

RFI testing station

EN 55011: Boundary values and measuring systems for RF suppression for industrial, scientific and medical high frequency equipment (ISM), 1991 (see also CISPR 11 or VDE 0871)

Boundary values complying with EN 55011

Quasipeak (QP) and Average (AV) are two limits, neither of which must be exceeded and which are measured by two different test receivers. The test arrangement remains the same. These boundary values replace the boundary values given by the old standards for broadband and narrowband noise generators.

Boundary values are divided into class A and B.

Into class A fall those devices which should not be operated in residential buildings and should not be connected to power supplies which also supply these areas. Class A boundary values shall not be exceeded.

Into class B fall devices for which above restrictions do not apply. Class B boundary values shall not be exceeded.

EN 55022: Boundary values and measuring systems for RF suppression for information technology installations (Telecommunications) 1987 (see also CISPR 22 or VDE 0878).

Boundary values complying with EN 55022

Into class A fall all units which should be used in a commercial environment and should be used with a safety distance of 30 m to other units.

Into class B fall all units which have no restrictions on their use.

EN 55013: Boundary value and measuring techniques for RF suppression characteristics of radio receivers and connected applications.

EN 55014: Boundary values and measuring systems for RF suppression for electrical household appliances, handheld electrical tools and similar electrical products, 1993 (see also CISPR 14).

EN 55015: Boundary values and measuring systems for RF suppression for fluorescent lamps and lighting, 1993 (see also CISPR 13).

(EN 61000-3-2, IEC 61000-3-2)

Current harmonics represent a distortion of the normal sine wave provided by the utility. When a product such as an SCR switched load or a switching power supply distorts the current, harmonics at multiples of the power line frequency are generated. Two significant consequences arise as a result of harmonic generation. First, because of finite impedances of power lines, voltage variations are generated that other equipment on the line must tolerate. Second, when generated in a three-phase system, harmonics may cause overheating of neutral lines.

Power line harmonics are generated when a load draws a non linear current from a sinusoidal voltage. The harmonic component is an element of a Fourier series which can be used to define any periodic waveshape. The harmonic order or number is the integral number defined by the ratio of the frequency of the harmonic to the fundamental frequency (e.g., 150 Hz is the third harmonic of 50 Hz; n = 150/50).

After multiple postponement finishes at 1.1. 2001 the transition-period for the EN 61000-3-2, frequently called “PFC-Norm�?. It applies to all electrical and electronic devices with input current up to max. 16 A per phase, which are designed to connect to the general lowvoltage mains. Limits are set only for 220/380 V, 230/400 V and 240/415 V at 50 Hz.

This standard distinguishes four classes of equipment.

A Simmetric three phase equipment and all other equipment not in other classes

A harmonics test to conform to the standards must include an analysis of the incoming current up to the 40th harmonic (for f_N = 50 Hz, f_H = 2 kHz).

The IEC 61642 "Industrial a.c. networks affected by harmonics- application of filters and shunt capacitors" give guidance for the use of passive a.c. harmonic filters and shunt capacitors for the limitation of harmonics and power factor correction intended to be used in industrial applications, at low and high voltages.

(EN61000-3-3, IEC 61000-3-3, IEC 61000-3-5)

The appearance of flicker effects and voltage fluctuations on the mains supply is caused by varying loads connected to the mains. The most critical are the effects of voltage fluctuations on equipment such as lights and illumination. Here the light output and thereby the intensity is an exponential function of the supplied voltage. This fluctuation in light intensity is called flicker. Many people experience dizziness and headaches as a result.

There are various limit values depending on the type of voltage fluctuation (square, sinusoidal and mixed or erratic voltage fluctuation).

Flickers are measured by so-called flicker meters (arranged in compliance with EN 60808).

ESD (Electrostatic Discharge)

(EN 61000-4-2, IEC 61000-4-2)

One of the main interference sources, along with switching through radio interference, is electrostatic discharge from people and equipment.

Burst

(EN 61000-4-4, IEC 61000-4-4)

One of the most common and most dangerous sources of interference are transient disturbances such as those originating from switching transients (interruption of inductive loads, relay contact bounce, etc.). The burst test measures the resistance of the device to repetitive fast transients.

Surge

(EN 61000-4-5, IEC 61000-4-5)

This test procedure measures the behaviour of a device when subjected to high-energy pulses. Sources of such pulses are switching events due to lightning strikes, short-circuits, or switching cycles which vary in time and place. Surge test on SCHURTER filters are according to EN 133200.

Specification of the burst test impulse

Surge voltage form in open circuit

The application range of pulse transformers is very broad. In most cases, a signal or a control pulse must be transmitted between electrically isolated circuits. This problem exists in the activation of thyristors and triacs, or in the operation of FETs or IGBTs in highpower switching circuits. Another application involves electrical isolation in telephone switchboards and data transfer systems.

When used in power electronics, the secondary side of pulse transformers is normally at a high voltage potential. This requires a high insulation strength for pulse transformers.

Complying with VDE 110 b, Part 1, the following test voltages between the primary and the secondary circuits are required for transformers of protection class I and choke coils, as a function of the working voltage:

The test voltage for SCHURTER pulse transformers depend on the type of winding and coating on the coil wire. Exact information concerning each type is available in the technical specifications. The test voltage is in each case considerably higher than that prescribed by VDE 110 b.

Partial discharges during normal operation have little effect on the operation of the circuit, but can accelerate the ageing of the pulse transformer. The glow discharge and the intermittent voltages are at least 50% higher than the approved working voltages for all SCHURTER pulse transformers. This provides the best assurance against long-term damage.

Over the almost straight-line in the lower 2/3 of the rise curve, i.e. in the area where the semiconductor is triggered with certainty, we draw a line and measure the time from 10% to 90% of the overall pulse height.

The measurement is made with the following circuit. The load resistance R_L is given for each type.

For a turn ratio of 1:1, the test voltage is 10V;

For a turn ratio of 2:1, the test voltage is 20V, and so on.

The maximum trigger current is a guide value. For a given current, the drop in voltage over the secondary winding resistance is smaller than one volt.

The voltage-time integral is the product of the pulse height and width, measured at half pulse height. The voltage-time area is measured on the secondary side during operation under no load.

The voltage-time integral U_s • T_w is measured according to the principle of the following circuit. The same voltages as used for measuring the rise time are used.

Primary and secondary inductances are measured with a low-power signal of 0.1 mA/10 kHz at 25°C. The tolerance is -30% / +50%. The measured value can also vary up to ± 25% under temperature variation in the range 0°C to 70°C.

The coupling capacity is measured between the primary and one secondary winding. This value varies depending on the type of winding. Bifilar windings, designed for models with faster rise times, have higher coupling capacitances than the layer or selection windings.

In general, this value is not important with regards transmission properties. To guarantee effective interference protection from the control electronics, however, the smallest possible coupling capacity is desired.

In the given turn ratios, the first figure always refers to the primary winding. Hence a «1:1» pulse transformer has the same number of winding on both the primary and the secondary windings. The turn ratio «3:1:1» stands for one primary and two secondary windings with a transformation ratio of three to one between the primary and the secondary windings.

SCHURTER offers pulse transformers with other turn ratios than specified on the data sheets upon request.

Example of application

Power transistor in pulse operation

UL approbation

The plastic cases and the potting resin of all SCHURTER pulse transformers are fire resistant in compliance with UL 94 V-0.

Code

I¹⁾ T²⁾ N³⁾ F⁴⁾ - 0⁵⁾ 2⁶⁾ 35⁷⁾ - D1⁸⁾ 03⁹⁾

The PSDM-0DN1-5040 module is a DC/DC power supply converter designed to provide a galvanic isolated, regulated and monitored power to IGBT and MOSFET drivers. The module requires an input voltage of 12V_DC ± 10% and has dual outputs of 15V and –4V with a maximum supply current of 140 mA. This DC/DC module has a unique diagnostic output permitting the user to monitor the converter output voltage and thus to avoid damage to the power stages resulting from under voltages.

The IGBT driver modules PSDM-0DO2-5040 and PSDM-0DT2-5020 were developed to drive IGBT or MOSFET power transistors in an easy, safe and reliable way. The modules have an internal turnoff circuit that protects the output power stage in the event of a short circuit. The PSDM has an isolated DC/DC converter with a 2.4W output power for the drive circuit supply. (see PSDM-0DN1-5040). Data is transfered by an optocoupler or a transformer.

Connection description

fig. 1: PSDM

PIN1: V_DC

A stabilised voltage supply between 10V and 15V with respect to GND.

PIN2: GND

GND is connected to the frame of the electronic power supply.

PIN3: V_SM

This output refelects the output voltage of the DC/DC converter. When more current is needed at the output stage, the voltage across V_SM decreases. When V_SM reaches the value of the DC/DC

converter power supply, then the DC/DC converter has reached the maximum transfer current.

PIN4: V_CS1

VCS1 is the isolated positive output power supply for the driver logic.

PIN5: SGND

SGND is the electrically isolated output ground from the DC/DC converter.

PIN6: VC_S2

VCS2 is the isolated negative output power supply for the driver logic.

PIN7: V_ES

VES is the external power supply for the driver logic. V_ES is connected to V_CS2 to turn off the MOSFET/IGBT connected to the module.

PIN8: KGND

KGND is the isolated Kelvin ground that is connected to SGND.

PIN9: V_O

Output V_O is the signal output for the IGBT gate drive. In order to permit the switching speed to be set independently during turn-on and turn-off, two gate resistors and a diode must be used

(for example, R_g1 = 22 Ω and R_g2 = 100 Ω).

fig. 2: Gate Driver

PIN10: D_PR

This connection is used to monitor the voltage drop across the turned-on current transistor, so as to provide protection against short circuits and overloading on the IGBT. This involves monitoring the collector voltage and turning off the power transistor if this voltage rises above a certain threshold value. The best method of detecting an excess threshold value is through the use of an external fast or super-fast high voltage diode D1 (for example 1N4937) and an internal comparitor. The PSDM has power transistor supervision, which monitors the collector voltage on the IGBT. Under normal operating conditions when the IGBT is turned on and saturated, the voltage across DPR is kept low. When the IGBT is no longer saturated or turned off, the internal current source (270 μA) will trip out the comparitor. The comparitor threshold value is typically 6.5 V (D_PRth). Resistor RRV is required to protect the PSDM from reverse voltage transients and should not be larger than 1kΩ. The fault event is transferred to the output pin FLT by an internal optocoupler.

fig. 3: Power transistor supervision D_pr

PIN11: I_SEN

Input I_SEN is required to check the supply current across Risen, serving thus as a protection against short circuits and overvoltages on the IGBT. An RC filter is used across pins 8 and 11 to attenuate any high frerquency noise. If an overcurrent (V_ISOC> 65 mV) takes place across R_ISEN, IGBT will be turned off by an internal circuit. The signal fault is reset when another impulse appears at the signal input V_IN. In the event of a short circuit across the output (V_ISSC> 130 mV), inductance will be very small. Measured across resistor Risen, the short circuit signal is transfered by an internal optocoupler to the output pin FLT. If a short circuit is detected, the IGBT remains turned off until the next impulse (V_in).

fig. 4: Fault current detection I_sen

PIN12: FLT

The PSDM has an active fault output. This fault output is internally interfaced to an optocoupler. In a turned-on state, the current range of the optocoupler is between 10 to 20 mA, possessing a high impedance in the turned-off state. The integrated circuit is shown below.

fig. 5: Fault output

The FLT pin is only enabled when it is used together with a D_PR or I_SEN signal. Voltage V_FLT can be taken from 5V to 15V with a resistor. The supply current permitted is 10mA. In the event of a fault, output FLT is switched to GND.

PIN13: V_IN

This input has a SchmittTrigger characteristic. HIGH level turns the power transistor on, LOW turns it off.

PIN15: V_DD

A stabilised voltage supply between 4.5V and 5.5V with respect to GND.

Application example: Power supply 0-15V (fig. 6)

With this circuitry example, an output voltage of 0-15V is generated at V_0. The two functions fault current detection (ISEN) and power transistor supervision (D_PR) are inactively switched for this application. With this, SGND is connected to I_SEN, D_PR, V_ES and KGND. If necessary, a seprate resistor can be connected between V₀ and IGBT in order to optimize the turning on and off of the semi-conductor.

Application example: Power supply -4-15V (fig. 7)

With this circuitry example, an output voltage of -4-15V is generated at V₀. The two functions fault current detection (I_SEN) and power transistor supervision (D_PR) are inactively switched for this application.

With this, SGND is connected to I_SEN, D_PR, V_ES and KGND. If necessary, a seprate resistor can be connected between V0 and IGBT in order to optimize the turning on and off of the semi-conductor.

Application example: Power transistor supervision (figure 8)

In this example, power transistor supervision is presented for the IGBTs. For this, output V_CS2 (-4V) is connected to V_ES. Supervision is actively switched with the connection of V_CS1 to I_SEN. In addition, a high voltage diode is connected in series to a resistor between D_PR and the IGBT collector. The capacitor is switched from D_PR to SGND.

Application example: Fault current detection (figure 9)

With this example, a fault current detection circuitry is presented for the IGBTs. For this, output V_CS2 (-4V) is connected to V_ES. A resistor R_ISEN is connected between I_SEN and KGND. An RC filter is used to attenuate high frequency noise. A capacitor is needed between D_PR and KGND.

fig. 6: Power supply 0-15V

fig. 7: Power supply -4-15V

fig. 8: Power transistor supervision

fig. 9: Fault current detection

Automatic undervoltage turn-off

The PSDM module is equipped with undervoltage protection for the gate drive of the IGBT/MOSFET. Should the gate voltage be too low, the IGBT can quickly overheat; to avoid this, the undervoltage protection is arranged such that when the voltage drops below 10V, the gate voltage on the PSDM is turned off.

Layout and wiring (figure 10)

The driver module should be placed as close as possible to the power transistor so that the wiring is kept short. Long wiring connections should be avoided; it is recommended to twist the wires here.

fig. 10: Wiring