UTC2030 LINEAR INTEGRATED CIRCUIT 18W Hi-Fi AMPLIFIER AND 35W DRIVER DESCRIPTION The UTC2030 is a monolithic IC in Pentawatt package intended for use as low frequency class AB amplifier. With Vsmax=32V it is particularly suited for more reliable applications without regulated supply and for 35W driver circuits using lowcost complementary pairs. The UTC2030 provides high output current and has very low harmonic and cross-over distortion. Further the device incorporates a short circuit protection system comprising an arrangement for automatically limiting the dissipated power to as to keep the working point of the output transistors within their safe operating area. A conventional thermal shut-down system is also included. TO-220B ABSOLUTE MAXIMUM RATINGS(Ta=25°C) CHARACTERISTICS SYMBOL VALUE UNITS Supply Voltage Input Voltage Differential input voltage Peak output current (internally limited) Total power dissipation at Tcase=90°C Storage temperature junction temperature Vs Vi Vdi Io Ptot Tstg Tj ±20 Vs ±13 3.5 20 -40~+150 -40~+150 V V V A W °C °C TYPICAL APPLICATION +Vs Vi μ C5 100nF μ C1 1 F C3 100 F D1 1N4001 1 Ω R3 22k 5 4 UTC2030 2 3 Ω μ C8 Ω R4 1 Ω 1N4001 R3 680 C2 22 F R5 R1 22k μ C6 100 F D1 RL C4 C7 100nF 220nF -Vs YOUWANG ELECTRONICS CO.LTD 1 UTC2030 LINEAR INTEGRATED CIRCUIT PIN CONNECTION 1 Non inverting input 2 Inverting input 3 -Vs 4 Output 5 +Vs ELECTRICAL CHARACTERISTICS(Refer to the test circuit,Vs=±16V,Ta=25°C) PARAMETER SYMBOL Supply Voltage Quiescent drain current Input bias current Input offset voltage Input offset current Vs Id Output power Power bandwidth Slew rate Open loop voltage gain Closed loop voltage gain Total Harmonic distortion Total Harmonic distortion Second order CCIF intermodulation distortion Third order CCIF intermodulation distortion Input noise voltage Input noise current Signl to Nois rtio TEST CONDITIONS BW SR Gvo TYP MAX UNIT 50 ±18 80 V mA 0.2 ±2 ±20 2 ±20 ±200 µA mV nA ±6 Ib Vos Ios Po MIN Vs=±16v d=0.5%, Gv=26dB f=40 to 15kHz RL=4Ω RL=8Ω Po=15W, RL=4Ω 15 10 18 12 100 8 80 25.5 26 W W kHz V/µsec dB f=1kHz Gvc d d d2 d3 S/N 26.5 dB Po=0.1 to 14W, RL=4Ω f=40Hz to 15kHz Po=0.1 to 14W, RL=4Ω f=1kHz Po=0.1 to 9W, RL=8Ω f=40Hz to 15kHz Po=4W, RL=4Ω f2-f1=1kHz 0.08 % 0.03 % 0.5 % 0.03 % f2=14KHz, f1=15kHz 0.08 % B=curve A B= 22Hz to 22kHz RL=4Ω, Rg=10kΩ, B=curve A Po=15W Po=1W YOUWANG ELECTRONICS CO.LTD 2 3 106 94 10 µV µV dB dB 2 UTC2030 LINEAR INTEGRATED CIRCUIT (continued) PARAMETER SYMBOL Input Resistance (pin 1) Supply Voltage rejection Thermal Shut-down junction temperature TEST CONDITIONS open loop, f=1kHz MIN TYP 0.5 5 MΩ 54 dB 145 °C RL=4Ω, Gv=26dB Rg=22kΩ, f=100Hz MAX UNIT TEST CIRCUITS +Vs Vi μ C5 220 F μ C1 1 F C3 100nF D1 1N4001 1 Ω R3 22k 5 4 UTC2030 2 3 Ω R1 13k Ω D1 1N4001 R3 680 μ C2 22 F Ω R4 1 μ C6 220 F RL C4 C7 100nF 220nF -Vs YOUWANG ELECTRONICS CO.LTD 3 UTC2030 LINEAR INTEGRATED CIRCUIT +Vs 100k Ω 1N4001 1 5 Ω 2 4.7k 4 UTC2030 μ F 100k 220 3 Ω 100k Ω Ω R4 1 Ω 1N4001 μ 2.2 F 2200 μF 22 μF μF 0.1 RL=4 Vi Ω μF 100k 2.2 C7 220nF Fig. 1 Single supply amplifier YOUWANG ELECTRONICS CO.LTD 4 UTC2030 LINEAR INTEGRATED CIRCUIT Fig.3 Output power vs. Supply voltage 140 Gv (dB) 180 Phase 100 90 60 0 Phase Fig.2 Open loop frequency response Po (W) 18 Gv=26dB d=0.5% f=40 to 15kHz 15 Ω RL=4 12 Gain 20 9 -20 6 -60 RL=8 3 1 10 2 10 3 10 4 10 5 10 6 10 7 10 22 Frequency (Hz) Fig.4 Total harmonic distortion vs. output power d (%) Ω Ω f=15kHz Vs=32V Po=4W RL=4 Gv=26dB Ω Order (2f1-f2) -1 10 Ω Vs=28V RL=4 f=1kHz -2 10 -1 10 0 10 1 10 Order (2f2-f1) 2 10 -2 10 1 10 2 10 3 10 4 10 Po (W) Fig.7 Maximum allowable power dissipation vs. ambient temperture ± Ω 30 Vo (Vp-p) 30 Vs= 15V RL=8 25 5 10 Frequency (Hz) Fig.6 Large signal frequency response Ptot (W) 25 ± Ω Vs= 15V RL=4 20 32 2 10 0 10 Vs=32V RL=8 -2 10 30 Vs (V) 1 10 Gv=26dB -1 10 28 Po (W) d (%) 0 10 26 Fig.5 Two tone CCIF intermodulation distortion 2 10 1 10 24 20 10 ℃ ℃ 5 ℃ nk 10 a Rt tsin h= k h 4 av he /W ing a ts R t in k h= ha v 8 /W ing ts i 15 ea eh init inf g v in h a /W ink ats 5 h e ty = 2 R he 15 5 1 10 2 10 3 10 4 10 -50 0 Frequency (kHz) YOUWANG ELECTRONICS CO.LTD 50 100 150 ℃) 200 Tamb ( 5 UTC2030 LINEAR INTEGRATED CIRCUIT Ω 4 UTC2030 2 3 R4 3.3k Ω μ μ R8 1 Ω BD907 R5 30k C4 10 F C8 2200 F μ 1N4001 R2 56k BD908 5 Ω C2 22 F Ω 1 R3 56k μ μ R6 1.5 Ω R7 1.5 C7 0.22 F Ω Ω RL=4 C3 0.22 F μ Ω C5 220 F /40V C6 0.22 F Vi C1 2.2 F μ R1 56k 1N4001 +Vs μ Fig. 8 Single supply high power amplifier(UTC2030+BD908/BD907) TYPICAL PERFORMANCE OF THE CIRCUIT OF FIG. 8 PARAMETER Supply Voltage Quiescent drain current Output power SYMBOL Vs Id Po Voltage Gain Slew Rate Total harmonic distortion Input sensitivity Gv SR d Signal to Noise Ratio S/N Vi TEST CONDITIONS MIN Vs=32V d=0.5%,RL=4Ω f=40Hz to 15kHz,Vs=32V d=0.5%,RL=4Ω f=40Hz to 15kHz,Vs=28V d=0.5%,f=1kHz, RL=4Ω,Vs=32V d=0.5%,RL=4Ω f=1kHz,Vs=28V f=1kHz TYP MAX UNIT 28 50 36 V mA 32 26 W 35 28 19.5 Po=20W,f=1kHz Po=20W,f=40Hz to 15kHz Gv=20dB,Po=20W, f=1kHz,RL=4Ω RL=4Ω,Rg=10kΩ B=curve A,Po=25W RL=4Ω,Rg=10kΩ B=curve A,Po=25W YOUWANG ELECTRONICS CO.LTD 20 8 0.02 0.05 890 108 100 20.5 dB V/µsec % % mV dB 6 UTC2030 LINEAR INTEGRATED CIRCUIT Fig. 10 Output power vs. supply voltage Fig. 11 Total harmonic distortion vs. output power Po (W) d (%) Ω Vs=32V RL=4 Gv=20dB 25 0 10 20 15 -1 10 f=15kHz 10 f=1kHz -2 10 5 22 24 26 28 30 Vs (V) 32 -1 10 0 10 Fig. 12 Output power vs. Input level 1 10 Po (W) Fig. 13 Power dissipation vs. output power Ptot (W) Po (W) 20 20 Complete Amplifier Gv=26dB 15 15 Gv=20dB 10 10 5 5 BD908/ BD907 UTC2030 0 100 250 400 550 0 Vi (mV) 700 0 8 16 24 32 Po (W) +Vs Vi μ C5 100 F μ C1 1 F C3 100nF D1 1N4001 1 Ω R3 22k 5 4 UTC2030 2 3 Ω Ω R1 22k R3 680 μ C2 22 F R5 μ C6 100 F C8 Ω R4 1 D2 1N4001 RL C4 C7 100nF 220nF -Vs Fig. 14 Typical amplifier with split power supply YOUWANG ELECTRONICS CO.LTD 7 UTC2030 LINEAR INTEGRATED CIRCUIT Vs+ μ C7 100nF C6 100 F IN 1 Ω R1 22k 5 4 UTC2030 2 3 μ C8 0.22 F μ C1 2.2 F Ω R3 22k Ω R8 1 μ C4 22 F Ω RL 8 Ω R4 680 Ω R7 22k Ω 5 4 UTC2030 2 Vs- 3 Ω R5 22k μ C9 0.22 F 1 R2 22k Ω R9 1 μ C5 22 F μ C2 100 F C3 100nF Ω R6 680 Fig. 16 Bridge amplifier with split power supply(Po=34W,Vs+=16V,Vs-=16V) Multiway speaker systems and active boxes Multiway loudspeaker systems provide the best possible acoustic performance since each loudspeaker is speciailly designed and optimizied to handle a limited range of frequencies.Commonly,these loudspeaker systems divide the audio spectrum two or three bands. To maintain a flat frequency response over the Hi-Fi audio range the bands cobered by each loudspeaker must overlap slightly.Imbalance between the loudspeakers produces unacceptable results therefore it is important to ensure that each unit generates the correct amount of acoustic energy for its segmento of the audio spectrum.In this respect it is also important to know the energy distribution of the music spectrum to determine the cutoff frequencies of the crossover filters(see Fig. 18).As an example,1 100W three-way system with crossover frequencies of 400Hz and 3khz would require 50W for tthe woofer,35W for the midrange unit and 15W for the tweeter. Both active and passive filters can be used for crossovers but active filters cost significantly less than a good passive filter using aircored inductors and non-electrolytic capacitors.In addition active filters do not suffer from the typical defects of passive filters: --Power less; --Increased impedance seen by the loudspeaker(lower damping) --Difficuty of precise design due to variable loudspeaker impedance. YOUWANG ELECTRONICS CO.LTD 8 UTC2030 LINEAR INTEGRATED CIRCUIT Obviously, active crossovers can only be used if a power amplifier is provide for each drive unit.This makes it particularly interesting and economically sound to use monolithic power amplifiers. In some applications complex filters are not realy necessary and simple RC low-pass and high-pass networks(6dB/octave) can be recommended. The result obtained are excellent because this is the best type of audio filter and the only one free from phase and transient distortion. The rather poor out of band attenuation of single RC filters means that the lodspeaker must operate linearly well beyond the crossover frequency to avoid distortion. A more effective solution,named "Active power Filter" by SGS is shown in Fig. 19. The proposed circuit can realize combined power amplifiers and 12dB/octave or 18dB octave high-pass or lowpass filters. In practive, at the input pins amplifier two equal and in-phase voltages are available, as required for the active filter operations. The impedance at the Pin(-) is of the order of 100Ω,while that of the Pin (+) is very high, which is also what was wanted. Fig. 18 Power distribution vs. frequency Fig. 19 Active power filter 100 C1 C2 C3 IEC/DIN NOISE SPECTRUM FOR SPEAKER TESTING 80 Vs+ Morden Music Spectrum RL 60 R1 R2 R3 3.3kΩ Vs- 40 100Ω 20 0 1 10 2 10 3 10 4 10 5 10 The components values calculated for fc=900Hz using a Bessel 3rd Sallen and Key structure are: C1=C2=C3=22nF,R1=8.2KΩ,R2=5.6KΩ,R3=33KΩ. Using this type of crossover filter, a complete 3-way 60W active loudspeaker system is shown in Fig. 20. It employs 2nd order Buttherworth filter with the crossover frequencies equal to 300Hz and 3kHz. The midrange section consistors of two filters a high pass circuit followed by a low pass network.With Vs=32V the output power delivered to the woofer is 25W at d=0.06%( 30W at d=0.5%).The power delivered to the midrange and the tweeter can be optimized in the design phase taking in account the loudspeaker efficiency and impedance(RL=4Ω to 8Ω). It is quite common that midrange and tweeter speakers have an efficiency 3dB higher than woofers. Musical instruments amplifiers Another important field of application for active system is music. In this area the use of several medium power amplifiers is more convenient than a single high power amplifier, and it is also more reliable. A typical example(see Fig. 21) consist of four amplifiers each driving a low-cost, 12 inch loudspeaker. This application can supply 80 to 160W rms. YOUWANG ELECTRONICS CO.LTD 9 UTC2030 LINEAR INTEGRATED CIRCUIT Transient inter-modulation distortion(TIM) Transient inter-modulation distortion is an unfortunate phenomena associated with negative-feedback amplifiers. When a feedback amplifier receives an input signal which rises very steeply, i.e. contains high-frequency components, the feedback can arrive too late so that the amplifiers overloads and a burst of inter-modulation distortion will be produced as in Fig.22.Since transients occur frequently in music this obviously a problem for the designed of audio amplifiers. Unfortunately, heavy negative feedback is frequency used to reduce the total harmonic distortion of an amplifier, which tends to aggravate the transient inter-modulation(TIM situation.)The best known Vs+ Ω 1 UTC2030 2200 Ω μF Ω 3.3k 100 BD907 Ω Ω μ Ω 4 22k μ 3 μF 1 33nF 2 100 BD908 4 F 680O Ω 5 0.22 22k 1.5 0.22 F 2200 Ω 0.22 F 22k 1N4001 μF 18nF 1 Ω 1.5 IN μ 1N4001 F μ Low-pass 300Hz Woofer Band-pass 300Hz to 3kHz 0.22 μF Vs+ 1N4001 μF 22k Ω 1 6.8k Ω 5 2 220 4 UTC2030 μF Ω 3 Ω μ F 3.3nF 3.3k Ω Ω 22k 0.22 8 0.1 1 μF 18nF 0.1 1N4001 100 μF 2.2k 100 Ω 0.22 High-pass 3kHz 12k 22k Ω 1 Ω 5 UTC2030 2 100 4 3 μ 1N4001 μF Ω 0.22 Ω 22k 100 F μ 1N4001 μF 8 0.1 μF 1O Ω μF Midrange Vs+ F 0.1 22k Vs+ Ω 47 100 Ω μF 2.2k Ω High-pass 3kHz YOUWANG ELECTRONICS CO.LTD Tweeter 10 UTC2030 LINEAR INTEGRATED CIRCUIT Fig.21 High power active box for musical instrument Fig.22 Overshoot phenomenon in feedback amplifiers FEEDBACK PATH 20 to 40W Amplifier βV4 INPUT PRE AMPLIFIER V1 V2 V3 POWER AMPLIFIER OUTPUT V4 20 to 40W Amplifier V1 20 to 40W Amplifier V2 20 to 40W Amplifier V3 V4 method for the measurement of TIM consicts of feeding sine waves superimposed onto square wavers,into the amplifier under test.The output spectrum is then examined using a spectrum analyser and compared to the input.This method suffers from serious disadvantages:the accuracy is limited, the measurement is a tather delicate operation and an expensive spectrum analyser is essential.A new approach (see Technical Note 143(Applied by SGS to monolithic amplifiers measurement is fast cheap,it requires nothing more sophisticated than an oscilloscope-and sensitive-and it can be used down to the values as low as 0.002% in high power amplifiers. The "inverting-sawtooth" method of measurement is based on the response of an amplifier to a 20KHz sawtooth waveform.The amplifier has no difficulty following the slow ramp but it cannot follow the fast edge.The output will follow the upper line in Fig.23 cutting of the shade area and thus increasing the mean level.If this output signal is filtered to remove the sawtooth,direct voltage remains which indicates the amount of tIM distortion, although it is difficult to measure because it is indistingishable from the DC offset of the amplifier.This problem os neatly avoided in the IS-TIM method by periodically inverting the sawtooth waveform at a low audio frequency as shown in Fig.24.Inthe case of the sawtooth in Fig. 25 the means level was increased by the TIM distortion, for a sawtooth in the other direction the opposite is ture. SR(V/µs) Input Signal m2 m1 Filtered Output Siganal Fig.23 20kHz sawtooth waveform Fig.24 Inverting sawtooth waveform YOUWANG ELECTRONICS CO.LTD 11 UTC2030 LINEAR INTEGRATED CIRCUIT The result is an AC signal at the output whole peak-to-peak value is the TIM voltage,which can be measured easily with an oscilloscope.If the peak-topeak value of the signal and the peak-to-peak of the inverting sawtooth are measured,the TIM can be found very simply from: VOUT TIM = * 100 Vsawtooth Fig. 25 TIM distortion Vs. Output Power Fig. 26 TIM design diagram(fc=30kHz) 1 10 2 10 SR(V/ UTC2030 BD908/907 Gv=26dB Vs=32V RL=4 Ω 0 10 -2 10 -1 10 0 10 RC Filter fc=30kHz 1 10 RC Filter fc=30kHz -1 10 祍) 0 10 1 10 Po(W) 2 10 TI M =0 .0 TI 1% M =0 . TI 1% M =1 % TIM(%) -1 10 -1 10 0 10 1 10 2 10 Vo(Vp-p) In Fig.25 The experimental results are shown for the 30W amplifier using the UTC2030 as a driver and a low-cost complementary pair.A simple RC filter on the input of the amplifier to limit the maxmium signal slope(SS) is an effective way to reduce TIM. The Digram of Fig.26 originated by SGS can be used to find the Slew-Rate(SR) required for a given output power or voltage and a TIM design target. For example if an anti-TIM filter with a cutoff at 30kHz is used and the max.Peak to peak output voltage is 16V then, referring to the diagram, a Slew-Rate of 6V/µs is necessary for 0.1% TIM. As shown Slew-Rates of above 10V/µs do not contribute to a further reduction in TIM. Slew-Rates of 100V/µs are not only useless but also a disadvantage in Hi-Fi audio amplifiers because they tend to turn the amplifier into a radio receiver. Power Supply Using monolithic audio amplifier with non regulated supply correctly.In any working case it must provide a supply voltage less than the maximum value fixed by the IC breakdown voltage. It is essential to take into account all the working conditions, in particular mains fluctuations and supply voltage variations with and without load.The UTC2030(Vsmax=32V) is particularly suitable for substitution of the standard IC power amplifiers(with Vsmax=28V) for more reliable applications. An example, using a simple full-wave rectifier followed by a capacitor filter, is shown in the table and in the diagram of Fig.27. A regulated supply is not usually used for the power output stages because of its dimensioning must be done taking into account the power to supply in signal peaks.They are not only a small percentage of the total music signal, with consequently large overdimensioning of the circuit. Even if with a regulated supply higher output power can be obtained(Vs is constant in all working conditions),the additional cost and power dissipation do not usually justify its use.using non-regulated supplies,there are fewer designe restriction.In fact,when signal peaks are present, the capacitor filter acts as a flywheel supplying the required energy. YOUWANG ELECTRONICS CO.LTD 12 UTC2030 LINEAR INTEGRATED CIRCUIT In average conditions,the continuous power supplied is lower.The music power/continuous power ratio is greater in case than for the case of regulated supplied,with space saving and cost reduction. Fig.27 DC characteristics of 50W non-regulated supply Ripple (Vp-p) Vo(V) 26 24 Ripple 4 22 220V μ 2 Vo 3300 F 20 Vout 0 18 0 0.4 0.8 1.2 1.6 2.0 Io(A) Mains(220V) Secondary voltage +20% +15% +10% 23.0V 22.1V 21.1V 19.2V 17.3V 16.3V 15.3V — -10% -15% -20% DC output Voltage(Vo) Io=0 34.5V 33.1V 31.7V 29.0V 25.9V 24.5V 23.0V Io=0.1A 33.6V 32.2V 30.8V 28.0V 25.2V 23.8V 22.4V Io=1A 30.0V 28.6V 27.3V 24.8V 22.2V 20.8V 19.4V Short Circuit Protection The UTC2030 has an original circuit which limits the current of the output transistors.This function can be considered as being peak power limiting rather than simple current limiting.It reduces the possibility that the device gets damaged during an accidental short circuit from AC output to Ground. Thermal Shut-Down The presence of a thermal limiting circuit offers the following advantages: 1).An overload on the output (even if it is permanent),or an above limit ambient temperture can be easily supported since the Tj can not be higher than 150°C 2).The heat-sink can have a smaller factor of safety compared with that of a convential circuit,There is no possibity of device damage due to high junction temperature increase up to 150, the thermal shut-down simply reduces the power dissipation and the current consumption. YOUWANG ELECTRONICS CO.LTD 13 UTC2030 LINEAR INTEGRATED CIRCUIT APPLICATION SUGGESTION The recommended values of the components are those shown on application circuit of Fig.14. Different values can be used.The following table can help the designer. Component Recommended value Purpose Large than recommended value Large than recommended value R1 22KΩ Increase of Gain Decrease of Gain R2 680Ω Decrease of Gain Increase of Gain R3 22KΩ R4 1Ω Closed loop gaon setting. Closed loop gaon setting. Non inverting input biasing Frequency stacility R5 ≈3R2 C1 1µF C2 22µF C3,C4 0.1µF C5,C6 100µF C7 C8 0.22µF ≈1/(2π*B*R1) D1,D2 1N4001 Increase of input Decrease of input impedance impedance Danger of oscillation at high frequencies with inductive loads. Upper frequency Poor high frequencies Dange of oscillation attenuation cutoff Input DC decoupling Increase of low frequencies cutoff Inverting DC Increase of low decoupling frequencies cutoff Supply voltage Dange of oscillation bypass Supply voltage Dange of oscillation bypass Frequency stability Larger bandwidth Upper frequency smaller bandwidth Larger bandwidth cutoff To protect the device against output voltage spikes. YOUWANG ELECTRONICS CO.LTD 14