Technical Information Type Designation in Accordance with Pro Electron 1 Type Designation in Accordance with Pro Electron This type designation applies to small-signal semiconductor components - in contrast to integrated circuits, multiples of these components and semiconductor chips. The number of the basic type consists of: two letters and a three-digit code. First Letter gives information about the material. A. B. C. R. Germanium or other material with a band gap of 0.6 ... 1.0 eV Silicon or other material with a band gap of 1.0 ... 1.3 eV Gallium-arsenide or other material with a band gap of 1.3 eV Compound material, e.g. cadmium-sulfide Second Letter Indicates the function for which the device is primarily designed. A. B. C. D. E. F. G. H. L. N. P. Q. R. S. T. U. X. Y. Z. Diode: signal, low power Diode: variable capacitance Transistor: low power, audio frequency Transistor: power, audio frequency Diode: tunnel diode Transistor: low power, high frequency Multiple of dissimilar devices; miscellaneous devices (e.g. oscillator) Diode: magnetic sensitive Transistor: power, high frequency Optocoupler Radiation-sensitive semiconductor component Radiation-emitting semiconductor component Control or switching device: low power (e.g. thyristor) Transistor: low power, switching Control or switching device: power (e.g. thyristor) Transistor: power switching Diode: multiplier, e.g. varactor, step recovery Diode: rectifier, booster Diode: voltage reference or regulator; transient voltage suppressor diode The three-digit code of the type designation consists of: - a three-digit number, running from 100 to 999, for devices primarily intended for consumer equipment etc. - one letter and a two-digit number for devices primarily intended for industrial/ professional equipment. This letter has no fixed meaning. Data Book 1 2000-09-01 Technical Information Notation of the Symbols and Terms Used (DIN 41 785) 2 Notation of the Symbols and Terms Used (DIN 41 785) The current, voltage, power (AC, DC, or average values) and resistance types (AC or DC values) are indicated by using capital and small letters for the symbols. Symbols The instantaneous data of values varying with time are indicated by small letters. Examples: i, v, p Capital letters are used for DC, average, rms, and peak values of periodical functions of the current, the voltage, and the power - i.e. for constant quantities. Examples: I, V, P Subscripts for the Symbols The following subscripts are used: E, e B, b C, c F, f R, r M, m av Emitter Base Collector Forward direction (diode operated in forward direction) Reverse direction (diode operated in reverse direction) Peak value Average value The subscripts for peak and average values may be omitted provided that a confusion with other values is impossible. Total values (instantaneous values, DC values, average, rms, and peak values) referred to a zero point are indicated by subscripts with capital letters. Examples: iC, IC, vBE, VBE, pC, PC Subscripts with small letters are used for the values of variable components (e.g. for instantaneous values, peak, and rms values referred to an average value). Examples: ic, Ic, vbe, Vbe, pc, Pc To distinguish between peak, average, and rms values, further subscripts may be added. The following abbreviations are recommended: Peak values M, m Average values Av, av Examples: ICM, ICAV, Icm, Icav Peak values may also be indicated by placing the symbol "" over the letter. Examples: IC, Ic Data Book 2 2000-09-01 Technical Information Maximum Ratings 3 Maximum Ratings The maximum ratings specified are absolute ratings which, if exceeded, may result in the destruction or permanent functional impairment of the component. When testing the component, as for example in respect to breakdown voltages, or during application, protection is to be provided in order to reliably ensure that maximum ratings are not exceeded. 4 Characteristics Typical characteristics describe the component behavior at defined operating conditions. The numerical values and diagrams pertain to the component type and shall not be considered as characteristics of an individual component. The minimum and maximum ratings stated for reasons of essential quality and application requirements describe the actual spread of the characteristics, whereas spread curves in diagrams usually specify the spread range which is to be expected. Electrical values are grouped into "static" DC values and "dynamic" AC values. The thermal resistance is closely related to the maximum ratings and, constituting the upper spread value, comes immediately after the maximum ratings. The component's case data is defined by reference to standard sheets and dimensional drawings. Figure 1 IC ICAV ICM, IC ICRMS DC value, no signal Average value of the total current (referred to zero) Peak value of the total current (referred to zero) RMS value of the total current (referred to zero) Data Book 3 2000-09-01 Technical Information Characteristics Icav Average value of the variable component superimposed on the closed-circuit direct current IC (referred to the DC no-signal value IC) Ic, Icrms Icm, Ic iC ic RMS value of the variable component (referred to the average value ICAV) Peak value of the variable component (referred to the average value ICAV) Instantaneous total value (referred to zero) Instantaneous value of the variable component (referred to the average value ICAV) The following relations apply to the values indicated in the above-mentioned diagram: ICAV = IC + Icav ICM = IC = ICAV + Icm 2 I CRMS = 2 I CAV + I crms IC = ICAV + iC Basic Symbol Chart The following chart illustrates the application of capital and small letter symbols. Table 1 Symbols e b i, v, p I, V, P Instantaneous value of the variable component RMS, average, and peak value of the variable component Instantaneous total value (as referred to zero) DC value, average, rms, and peak value (as referred to zero) c f Subscripts r m av E B C F R M AV Data Book 4 2000-09-01 Technical Information Characteristics Instructions for the Subscript Sequence Voltages As a rule, two subscripts are used to indicate the points between which the voltage is measured. Positive numerical values of the voltages correspond to positive potentials on the point indicated by the first subscript as referred to the point indicated by the second subscript (point of reference). The second subscript may be omitted if this cannot lead to confusion or misunderstandings. A supply voltage may be indicated by repeating the subscript of the terminal concerned. Examples: VEEB, VBBC, VCCE Currents As a rule, at least one subscript is used. Positive numerical values of the current correspond to positive currents entering the component at the terminal indicated by the first subscript. Subscripts for Terminals In the case of components having more than one terminal of the same type, the subscripts for the terminals may be modified by suffixing a number to them. Subscript and suffix must be written on the same line. Example: VB2-E (voltage between second base terminal and emitter) If several components form an assembly, the subscripts for the terminals may be modified by prefixing a number to them, subscript and prefix having to be written on the same line. Example: V1B-2B (voltage between the base of the first component and the base of the second component) Admittances, Resistances, Four-Pole Network Coefficients, etc. Symbols Small letters with appropriate subscripts are used for four-pole network coefficients, as well as resistances, admittances, capacitances, inductances, etc., which describe the features of the component. Examples: h11b, h11e, z21b, y22c Data Book 5 2000-09-01 Technical Information Characteristics Capital letters with appropriate subscripts are used for four-pole network coefficients, as well as resistances, admittances, capacitances, inductances, etc. of external network or of networks in which the component forms just a part. Examples: H11b, H11e, Z21b, Y22c Capital-letter subscripts are used for DC values (including large-signal values) of fourpole network coefficients, as well as, of resistances, admittances, etc. The DC value is the slope of the straight line from the origin of the coordinate system to the operating point on the characteristic of the component. Examples: rB, h11B, hFE Small-letter subscripts are used for AC values (small-signal values) of four-pole network coefficients, as well as of resistances, admittances, capacitances, inductances, etc. Examples: rbb, h11b, hfe The first subscript or the first pair of subscripts written in the manner customary for matrix elements is used for determining the elements of a four-pole network matrix. 11 (or i) 22 (or o) 21 (or f) = input = output = forward transfer 12 (or r) = reverse transfer Examples: V1 = h11 x I1 + h12 x V2 I2 = h21 x I1 + h22 x V2 Note When written in matrix representation (or as elements of matrixes) the voltage and current symbols are supplemented by a subscript consisting of a single numeral. Subscript 1 = input Subscript 2 = output The second subscript or the subscript following the pair of numerals indicates the basic circuit. If the common terminal is self-evident, the second subscript may be omitted e = common emitter configuration b = common base configuration c = common collector configuration Examples: (common base configuration) I1 = y11b x V1b + y12b x V1b I2 = y21b x V1b + y22b x V2b If the transistor is described with a four-pole characteristic, it is recommended to fix the direction arrows for the input and output currents in the direction of the four-pole network. Data Book 6 2000-09-01 Technical Information Alphanumerical List of the Symbols Used 5 Alphanumerical List of the Symbols Used a On-off base current ratio Anode Static current gain in common base configuration Dynamic short-circuit current gain in common base configuration A A b b11 b12 b21 b22 B, b C, c C Cb'c Cb'e Cc Ccase Ccb CCBO Cc'b Cce Cdg1 Cdss Ceb CEBO Ce'b Cg1ss Cg2ss Cib CL Cob Cth CT CT1/CT28 CT/CT C11 Data Book Imaginary part of y-parameters Imaginary part of the short-circuit input admittance (of parameter y11) Imaginary part of the short-circuit reverse transfer admittance (of parameter y12) Imaginary part of the short-circuit forward transfer admittance (of parameter y21) Imaginary part of the short-circuit output admittance (of parameter y22) Base terminal Collector terminal Capacitance Intrinsic base collector capacitance Intrinsic base emitter capacitance Collector junction capacitance (in general) Case capacitance (in general) Collector base capacitance Collector base capacitance (including case capacitance) with open emitter (IE = 0) Intrinsic collector base capacitance Collector-emitter capacitance Reverse transfer capacitance Output capacitance Emitter-base capacitance Emitter-base capacitance (including case capacitance) with collector open (IC = 0) Intrinsic emitter base capacitance Gate1 input capacitance Gate2 input capacitance Input capacitance Load capacitance Output capacitance Thermal capacity (disregarding of heat dissipation to the environment) Diode capacitance Capacitance ratio (CT (VR = 1 V) / CT (VR = 28 V)) Capacitance matching Capacitance of the short-circuit input admittance (of parameter y11) 7 2000-09-01 Technical Information Alphanumerical List of the Symbols Used C12 C22 Capacitance of the short-circuit reverse transfer admittance (of parameter y12) Capacitance of the short-circuit forward transfer admittance (of parameter y21) Capacitance of the short-circuit output admittance (of parameter y22) D Duty cycle D = tp / T E, e Emitter terminal f Frequency difference Frequency Cutoff frequency Cutoff frequency of the short-circuit small signal current gain in common base configuration Cutoff frequency of the short-circuit small signal current gain in common emitter configuration Frequency at which hfe = 1 Maximum frequency of oscillation Transition frequency (Current gain-bandwidth product) Noise figure C21 f fC fhfb fhfe fhfe1 fmax fT F g g gb'c gb'e gce gm; gfs gth gthJC g11 g12 g21 g22 G G Ga Gg GL Data Book Real part of the y-parameters Conductance (instantaneous value) Intrinsic base collector conductance Intrinsic base emitter conductance Collector emitter conductance Transconductance Coefficient of thermal conductivity (instantaneous total value) Coefficient of thermal conductivity (total instantaneous value) between heat source and case, with infinitely good heat dissipation from the case (Tcase = Tamb) Real component of the short-circuit input admittance (of parameter y11) Real component of the short-circuit reverse transconductance (of parameter y12) Real component of the short-circuit forward transconductance (of parameter y21) Real component of the short-circuit output admittance (of parameter y22) Conductance (DC or average value) Gain flatness Associated gain Internal conductance of generator Load conductance 8 2000-09-01 Technical Information Alphanumerical List of the Symbols Used Gma Gms Gp Gp Gpb Gpe Gpopt Gpbinv Gpbopt Gpeopt Gth GthA GV Power gain (Maximum available gain) Power gain (Maximum stable gain) Gain control range Power gain Power gain in common base configuration Power gain in common emitter configuration Power gain, optimum Reverse power loss (feedback damping) Power gain in common base configuration, optimum Power gain in common emitter configuration, optimum Coefficient of thermal conductivity (thermal conduction constant) Coefficient of thermal conductivity (thermal conduction constant) between heat source and static ambient air when using a cooling plate of defined size Coefficient of thermal conductivity (thermal conduction constant) between heat source and static ambient air. Coefficient of thermal conductivity (thermal conduction constant) between heat source and case, with infinitely good heat dissipation from the case (Tcase = Tamb) Voltage gain opt Reflection coefficient for minimum noise h h11 h12 h21 h22 hFE Parameter of the hybrid-matrix (h-matrix) Short-circuit input impedance Open-circuit reverse voltage transfer ratio (voltage feedback ratio hre) Short-circuit forward current transfer ratio (small signal current gain) Open-circuit output admittance DC current gain in common emitter configuration (static forward current transfer ratio) Small-signal current gain in common emitter configuration ( = h21 e) Small-signal current gain in common emitter configuration at f = 1 kHz (Dynamic short-circuit forward current transfer ratio in common emitter configuration) GthJA GthJC hfe hfeo i1 i2 IB IB1 IB2 IBM IC ICBO ICEO Data Book Input AC current Output AC current (in general) Base current (DC or average value) Control current, base-one current (UJT) Turn-off base current, on-off base current (UJT) Peak base current Collector current (DC or average value) Collector cutoff current with open emitter (IE = 0) Collector cutoff current with open base (IB = 0) 9 2000-09-01 Technical Information Alphanumerical List of the Symbols Used ICER ICES ICEV ICM ID IDSS IE IEBO IEM IF IFM IFS IG IG1SS IG2SS IK Io IR IP3 k Collector cutoff current with RBE = R (with a resistance RBE between base and emitter) Collector cutoff current with short-circulated emitter diode (VBE = 0) Collector cutoff current with reverse emitter diode Peak collector current Drain current Drain source saturation current Emitter current (DC or average value) Emitter cutoff current with open collector (IC = 0) Peak emitter current Forward current Peak forward current Surge current, maximum 1 sec Gate leakage current Gate1-source leakage current Gate2-source leakage current Short-circuit current Rectified current Reverse current Third order intercept point K Stability factor Cathode L Ls Inductance Series inductance m In a subscript: maximum (peak value) Degree of modulation In a subscript: maximum (e.g. upper scattering limit) in a subscript: minimum (e.g. Iower scattering limit) in a subscript: maximum (peak value) m max min M NF, F Noise figure NFmin, Fmin Minimum noise figure NF50, F50Noise figure 50 -System P; p PAE Pp Ptot P- 1dB Data Book Power dissipation Power added efficiency Pulse power dissipation Total power dissipation RF output power at 1 dB compression point 10 2000-09-01 Technical Information Alphanumerical List of the Symbols Used 11 12 21 22 Phase of y-parameters Phase of the short-circuit input admittance (of parameter y11) Phase of the short-circuit reverse transfer admittance (of parameter y12) Phase of the short-circuit forward transfer admittance (of parameter y21) Phase of the short-circuit output admittance (of parameter y22) Q Q factor (Quality factor) r rbb' rbb' Cb'c rcc reb rf R RBE Rg RL RN rN Rs Rth Rthc RthJA RthJS RthJT Resistance (instantaneous value) Base intrinsic resistance Feedback time constant Collector intrinsic resistance Emitter intrinsic resistance Forward resistance of diodes Resistance (DC or average value) Resistance between base and emitter Internal resistance of generator Load resistance Equivalent noise resistance Normalized equivalent noise resistance Series resistance Thermal resistance Thermal resistance of a chassis plate (cooling plate, no heat sink) Thermal resistance between junction (heat source) and static ambient air Thermal resistance between junction and soldering point Thermal resistance between junction and Chip base (Chip thermal resistance) Thermal resistance between chip base and soldering point (package / alloy layer) Thermal resistance between soldering point and ambient (substrate thermal resistance) Thermal resistance between junction (heat source) and case at infinitely good heat dissipation from the case (Tcase = Tamb) Differential resistance RthTS RthSA RthJC RO S212 S11 S21 S12 S22 Data Book Power gain in 50 -system Input reflection coefficient in 50 -system Forward transmission coefficient in 50 -system Reverse transmission coefficient in 50 -system Output reflection coefficient in 50 -system 11 2000-09-01 Technical Information Alphanumerical List of the Symbols Used t td tf tgt tgq th toff ton tp tq tr trr ts T T Tamb Tcase TCh Tj Tr TS Tstg Time Delay time Fall time Gate controlled turn-on time Gate controlled turn-off time In a subscript: thermal Turn-off time (toff = tS + tf) Turn-on time (ton = td + tr) Pulse duration Circuit commutated turn-off time Rise time Reverse recovery time Storage time Temperature Period duration Ambient temperature Case temperature Channel temperature Junction temperature Abbreviation for "transistor" Soldering point temperature Storage temperature Charge carrier life time v Voltage (instantaneous value) vFM Peak forward voltage vRF Input RF voltage vRM Peak reverse voltage vRS Maximum surge voltage, 1 sec v1 Input AC voltage v2 Output AC voltage V Voltage Vbatt Battery voltage VBB Base supply voltage VBE Base emitter voltage V(BR) ... Breakdown voltage V(BR) DS Drain-Source-breakdown voltage V(BR) G1SS Gate1-Source-breakdown voltage V(BR) G2SS Gate2-Source-breakdown voltage - VG1S(P) Gate1-Source Pinch-off voltage - VG2S(P) Gate2-Source Pinch-off voltage VCB Collector base voltage VCBO Collector-base voltage with open emitter (IE = 0) Data Book 12 2000-09-01 Technical Information Alphanumerical List of the Symbols Used VCC VDS VDG VGS VCE VCEO VCER VCES VCEsat VCEV VlN VEBO VF VGS(P), VP VO VOUT Vt Collector supply voltage Drain-source voltage Drain-gate voltage Gate-source voltage Collector emitter voltage Collector-emitter (reverse) voltage base open (IB = 0) Collector-emitter (reverse) voltage with a resistor between base and emitter Collector-emitter voltage with short-circulated emitter diode (VBE = 0) Collector-emitter saturation voltage Collector-emitter (reverse) voltage with reverse base emitter diode Input voltage Emitter-base voltage with open collector (IC = 0) Forward voltage Pinch-off voltage Open-circuit voltage Output voltage Tuning voltage Y Y11 Y12 Y21 Y22 Parameter of the admittance matrix (y-matrix) Short-circuit input admittance Short-circuit reverse transfer admittance Short-circuit forward transfer admittance Short-circuit output admittance z12 Z1 Z2 Reverse impedance with open input Input impedance (general) Output impedance (general) Collector or drain efficiency Angular frequency = 2 x x f Data Book 13 2000-09-01 Technical Information Explanation of the Symbols and Terms Used 6 Explanation of the Symbols and Terms Used This section contains brief explanations of the symbols and terms used in the data sheets for transistors. In order to distinguish between the different voltages and currents of the transistor, suffix letters are used. The letters provide information on the connection mode of the transistor terminals. The order on which they are indicated together with the sign (+ or -) indicates the direction of the voltage or current. The technical concept of current flow applies (current flow from + to -). The three transistor terminals are denoted as follows: Emitter E Base B Collector C In order to characterize the cutoff currents and reverse voltages a third suffix letter is used. This letter provides information on the connection mode of the third terminal which is otherwise not mentioned. Following abbreviations are used: O R S V The third, unmentioned terminal is open. Ohmic resistance between the terminal mentioned in the second place and the unmentioned terminal. Short circuit between the terminal mentioned in the second place and the unmentioned terminal. Reverse bias voltage between the terminal mentioned in the second place and the unmentioned terminal. 7 Technical Explanations 7.1 Basic Transistor Configurations Figure 2 Data Book Common Emitter Configuration 14 2000-09-01 Technical Information Technical Explanations Figure 3 Common Base Configuration Figure 4 Common Collector Configuration Table 2 Characteristics of the Basic Configurations Common Emitter Common Base Configuration Configuration Common Collector Configuration Input impedance medium low high Z1 Z1e Output impedance high very high low Z2 Z2e <1 high Small-signal current gain high hfe Voltage gain high high <1 Power gain very high high medium low high low Cutoff frequency fhfe Data Book 15 2000-09-01 Technical Information Technical Explanations 7.2 Explanations of Important Electrical Characteristics 7.2.1 DC Parameters Figure 5 VCER (ICER) Collector-emitter reverse voltage (collector-emitter cutoff current) with a resistor between base and emitter. The maximum permissible resistance value RBE is specified in the data sheets. The reverse voltage VCEO applies to higher values of RBE. Figure 6 VCBO (ICBO) Collector-base reverse voltage (collector-base cutoff current) with emitter open: IE = 0. Data Book 16 2000-09-01 Technical Information Technical Explanations Figure 7 VEBO (IEBO) Emitter-base reverse voltage (emitter-base cutoff current) with collector open: IC = 0. Figure 8 VCEO (ICEO) Collector-emitter reverse voltage (collector-emitter cutoff current) with base open: IB = 0. The state IB = 0 may also occur for a short while, e.g. in operation as a switch, with a resistance interposed between base and emitter. Figure 9 VCEV (ICEV) Collector-emitter reverse voltage (collector emitter cutoff current) with blocked emitter diode, i.e., reverse bias voltage between base and emitter. Data Book 17 2000-09-01 Technical Information Technical Explanations Figure 10 VCES (ICES) Collector-emitter reverse voltage (collector-emitter cutoff current) with shorted emitter diode: VBE = 0. 7.2.2 RF Parameters S 21 G ms = ------S 12 2 S 21 G ma = ------- x (k - k - 1) S 12 2 2 2 1 - S 11 - S 22 + S 11 S 22 - S 12 S 21 k = -----------------------------------------------------------------------------------------------2 S 12 S 21 Gma, Gms Maximum available gain if k 1 Maximum stable gain if k < 1 k Stability factor 2 ( S 21 ) dB = 10 x log S 21 2 2 S21 Insertion power gain in a 50 system without matching at input and output. f T = h 21 x f T Transition frequency, determined by S-parameter measurement and calculation. h21 Current gain f Measurement frequency Data Book 18 2000-09-01 Technical Information Thermal Resistance P P RF, OUT PAE = ---------------------------------P RF, IN + P DC RF, OUT = --------------------- P DC PAE Power Added Efficiency Efficiency (collector- or drain-efficiency) B Ccb Ceb C Cce E Ccb Collector-base capacitance Cce Collector-emitter capacitance Ceb Emitter-base capacitance 8 Thermal Resistance The heat caused by the power loss Ptot in the active semiconductor region during operation results in an increased temperature of the component. The heat is dissipated from its source (junction J or channel Ch) via the chip, the case and the substrate (pc board) to the heat sink (ambient A). The junction temperature TJ at an ambient temperature TA is determined by the thermal resistance RthJA and the power dissipation Ptot: TJ = TA + Ptot x RthJA (with RthJA in K/W or C/W) Figure 11 Data Book 19 2000-09-01 Technical Information RF and AF Transistors and Diodes in SMD Packages 9 RF and AF Transistors and Diodes in SMD Packages In SMD packages the heat is primarily dissipated via the pins. The total thermal resistance in this case is made up of the following components: RthJA = RthJT + RthTS + RthSA RthJS = RthJT + RthTS RthJA RthJS RthJT RthTS RthSA thermal resistance between junction and ambient (total thermal resistance) thermal resistance between junction and soldering point thermal resistance between junction and chip base (chip thermal resistance) thermal resistance between chip base and soldering point (package/alloy layer) thermal resistance between soldering point and ambient (substrate thermal resistance) RthJS contains all type-dependent quantities. For a given power dissipation Ptot it is possible to use it to precisely determine the component temperature if the temperature TS of the warmest soldering point is measured (for bipolar transistors typically the collector, for FETs the source lead). TJ = TS + Ptot x RthJS The temperature of the soldering point TS is determined by the application, i.e. by the substrate, heat produced by external components and the ambient temperature TA. These components combine to form the substrate thermal resistance RthSA that is circuitdependent and can be influenced by heat dissipation measures. TS = TA + Ptot x RthSA If measurement of the temperature of the soldering point TS is not possible, or if estimation of the junction temperature is sufficient, RthSA can be read from diagrams below. Here we give an approximate value of the thermal resistance RthSA between the soldering point on an epoxy or ceramic substrate and still air as a function of the area of the collector mounting or ceramic. The parameter is the dissipated power, i.e. the heat TS - TA of the pc board. So in this case for the operating temperature: TJ = TA + Ptot x (RthJS + RthSA) Data Book 20 2000-09-01 Technical Information RF and AF Transistors and Diodes in SMD Packages In the data sheets RthJS is stated as a thermal reference quantity of the heat dissipation. The total thermal resistance RthJA is stated for comparison purposes. Depending on the typical component application, substrates of the following kinds are used for reference: * AF applications epoxy circuit board: collector mounting area in cm2 Cu (see data sheets), thickness 35 m Cu. * RF applications ceramic substrate: 15 mm x 16.7 mm x 0.7 mm (alumina) or epoxy circuit board with collector mounting area corresponding to 80 K/W. The two diagrams below show, to an approximation, the thermal resistance as a function of the substrate area, assuming that the test device is located in the center of a virtually square substrate. Heat Dissipation from PC Board to Ambient Air (mounting pad Cu 35 m/ substrate: epoxy 1.5 mm) Data Book Heat Dissipation from Al2O3-Substrate to Ambient Air (substrate in still air, vertical 0.6 mm thick) 21 2000-09-01 Technical Information RF and AF Transistors and Diodes in SMD Packages 9.1 Temperature Measuring of Components Leads Measuring with temperature indicators (e.g. thermopaper) Temperature indicators do not cause heat dissipation and thus allow an almost exact determination of temperature. A certain degree of deviations can only result from roughgrade indication of the temperature indicators. This method is quite easy and provides sufficient accuracy. It is particularly suitable for measurement on pc boards. Measuring with thermocouple elements Measurement with thermocouple elements is not advisable because the functioning of the circuit can be influenced by the electrical conduction and the heat dissipation by the soldering point. This corrupts the results of the measurement, unless measurement is carried out with appropriate effort. 9.2 Permissible Total Power Dissipation in DC Operation The total power dissipation Ptot defines the maximum thermal gradient in the component. As a result of the heating of components, the maximum total power dissipation Ptot max stated in the data sheets is only permissible up to limits of TS max or TA max. These critical temperatures describe the point at which the maximum permissible junction temperature TJ max is reached. The maximum permissible ambient or soldering-point temperature is calculated as follows: TS max = TJ max - Ptot max x RthJS TA max = TJ max - Ptot max x RthJA In diodes the power dissipation is for the most part caused by internal resistance. So the diagram has to be translated into the form IF = f (TS; TA), resulting in the bent shape of the curve. For RthJA the appropriate standard substrate was taken in each case. The diagrams shown here are intended as examples. For the application the curve given in the data sheet is to be taken. Exceeding the thermal max. ratings is not permissible because this could mean lasting degradation of the component's characteristics or even its destruction. Data Book 22 2000-09-01 Technical Information RF and AF Transistors and Diodes in SMD Packages Total Power Dissipation Forward Current IF = f (TS; TA1)) 1) Ptot = f (TS; TA ) 1) Al2O3-Substrate 15 mm x 16.7 mm x 0.7 mm / Package mounted on alumina 15 mm x 16.7 mm x 0.7 mm 9.3 Permissible Total Power Dissipation in Pulse Operation In pulse operation, under certain circumstances, higher total power dissipation than in DC operation can be permitted. This will be the case when the pulse duration tp, i.e. the length of time that power is applied, is small compared to the thermal time constant of the system. This time constant, i.e. the time until the final temperature is reached, depends on the thermal capacitances and resistances of the components chip, case and substrate. The thermal capacitance utilized in the component is a function of the pulse duration. Here we describe this through the transient thermal resistance. The pulse-load thermal resistance, or the permissible increase in Ptot that can be derived from it, is shown by way of examples in the following curves. For the application the particular data sheet should be taken. Ptot max / Ptot DC = f (tp) The duty factor tp /T is given as a parameter for periodic pulse load with a period of T. For long pulse durations the factor Ptot max/Ptot DC approaches a value of 1, i.e. Ptot in pulsed operation can be equated with the DC value. At extremely short pulse widths, on Data Book 23 2000-09-01 Technical Information ESD (Electrostatic Discharge Sensitive Device) the other hand, the increase in temperature as a result of the pulse (residual ripple) becomes negligible and a mean temperature is created in the system that corresponds to DC operation with average pulse power. Permissible Pulse Load RthJS = f (tp) 10 Permissible Pulse Load Ptot max / Ptot DC = f (tp) ESD (Electrostatic Discharge Sensitive Device) ESD-sensitive components are supplied in anti-static packaging. The attached warning label calls your attention to the necessity of protecting the components against electrostatic discharge, beginning with the opening of the package. 11 Standards For detailed information please refer to the following DIN literature: DIN 41 782: Diodes DIN 41 785: Maximum Ratings DIN 41 791: General Instructions DIN 41 852: Semiconductor Technology DIN 41 853: Terms Relating to Diodes DIN 41 854: Terms Relating to Bipolar Transistors Data Book 24 2000-09-01