elecfans.com- TDA7385音频放大集成电路图

TDA7385 4 x 30W QUAD BRIDGE CAR RADIO AMPLIFIER HIGH OUTPUT POWER CAPABILITY: 4 x 35W/4Ω MAX. 4 x 30W/4Ω EIAJ 4 x 22W/4Ω @ 14.4V, 1KHz, 10% 4 x 18.5W/4Ω @ 13.2V, 1KHz, 10% CLIPPING DETECTOR LOW DISTORTION LOW OUTPUT NOISE ST-BY FUNCTION MUTE FUNCTION AUTOMUTE AT MIN. SUPPLY VOLTAGE DE- TECTION DIAGNOSTICS FACILITY FOR: – CLIPPING – OUT TO GND SHORT – OUT TO VS SHORT – THERMAL SHUTDOWN LOW EXTERNAL COMPONENT COUNT: – INTERNALLY FIXED GAIN (26dB) – NO EXTERNAL COMPENSATION – NO BOOTSTRAP CAPACITORS PROTECTIONS: OUTPUT SHORT CIRCUIT TO GND, TO VS, ACROSS THE LOAD VERY INDUCTIVE LOADS OVERRATING CHIP TEMPERATURE WITH SOFT THERMAL LIMITER LOAD DUMP VOLTAGE FORTUITOUS OPEN GND REVERSED BATTERY ESD PROTECTION DESCRIPTION The TDA7385 is a new technology class AB Audio Power Amplifier in Flexiwatt 25 package October 1999  ORDERING NUMBER: TDA7385 IN1 0.1µF MUTE ST-BY IN2 0.1µF OUT1+ OUT1- OUT2+ OUT2- PW-GND IN3 0.1µF IN4 0.1µF OUT3+ OUT3- OUT4+ OUT4- PW-GND PW-GND PW-GND D93AU002C AC-GND 0.1µF 47µF SVR TAB S-GND Vcc1 Vcc2 100nF2.200µF DIAGN. OUT BLOCK AND APPLICATION DIAGRAM FLEXIWATT25 1/12 designed for high end car radio applications. D94AU117B TA B P- G ND O UT 2- ST -B Y O UT 2+ V C C O UT 1- P- G ND 1 O UT 1+ SV R IN 1 IN 2 S- G ND IN 4 IN 3 AC -G ND O UT 3+ P- G ND 3 O UT 3- V C C O UT 4+ M UT E O UT 4- P- G ND 4 D IA G NO ST IC S 1 25 PIN CONNECTION (Top view) ABSOLUTE MAXIMUM RATINGS Symbol Parameter Value Unit VCC Operating Supply Voltage 18 V VCC (DC) DC Supply Voltage 28 V VCC (pk) Peak Supply Voltage (t = 50ms) 50 V IO Output Peak Current: Repetitive (Duty Cycle 10% at f = 10Hz) Non Repetitive (t = 100µs) 4.5 5.5 A A Ptot Power dissipation, (Tcase = 70°C) 80 W Tj Junction Temperature 150 °C Tstg Storage Temperature – 55 to 150 °C THERMAL DATA Symbol Parameter Value Unit Rth j-case Thermal Resistance Junction to Case Max. 1 °C/W Thanks to the fully complementary PNP/NPN out- put configuration the TDA7385 allows a rail to rail output voltage swing with no need of bootstrap capacitors. The extremely reduced components count allows very compact sets. The on-board clipping detector simplifies gain compression operations. The fault diagnostics makes it possible to detect mistakes during Car- Radio assembly and wiring in the car. DESCRIPTION (continued) TDA7385 2/12 ELECTRICAL CHARACTERISTICS (VS = 14.4V; f = 1KHz; Rg = 600Ω; RL = 4Ω; Tamb = 25°C; Refer to the Test and application circuit (fig.1), unless otherwise specified.) Symbol Parameter Test Condition Min. Typ. Max. Unit Iq1 Quiescent Current 180 300 mA VOS Output Offset Voltage 100 mV Gv Voltage Gain 25 26 27 dB Po Output Power THD = 10% THD = 1% THD = 10%; VS = 14V THD = 5%; VS = 14V THD = 1%; VS = 14V THD = 10%; VS = 13.2V THD = 1%; VS = 13.2V 20 16.5 19 17 16 17 14 22 18 21 19 17 18.5 15 W W W W W W W Po EIAJ EIAJ Output Power (*) VS = 13.7V 27.5 30 W Po max. Max. Output Power (*) VS = 14.4V 33 35 W THD Distortion Po = 4W 0.04 0.3 % eNo Output Noise ”A” Weighted Bw = 20Hz to 20KHz 50 65 150 µV µV SVR Supply Voltage Rejection f = 100Hz 50 65 dB fcl Low Cut-Off Frequency 20 Hz fch High Cut-Off Frequency 75 KHz Ri Input Impedance 70 100 KΩ CT Cross Talk f = 1KHz 50 70 dB ISB St-By Current Consumption St-By = LOW 100 µA VSB out St-By OUT Threshold Voltage (Amp: ON) 3.5 V VSB IN St-By IN Threshold Voltage (Amp: OFF) 1.5 V AM Mute Attenuation VO = 1Vrms 80 90 dB VM out Mute OUT Threshold Voltage (Amp: Play) 3.5 V VM in Mute IN Threshold Voltage (Amp: Mute) 1.5 V Im (L) Muting Pin Current VMUTE = 1.5V (Source Current) 5 10 16 µA ICDOFF Clipping Detector ”OFF” Output Average Current THD = 1% (**) 100 µA ICDON Clipping Detector ”ON” Output Average Current THD = 10% (**) 100 240 350 µA (*) Saturated square wave output. (**) Diagnostics output pulled-up to 5V with 10KΩ series resistor. TDA7385 3/12 IN1 0.1µF C9 1µF IN2 C2 0.1µF OUT1 OUT2 IN3 C3 0.1µF IN4 C4 0.1µF OUT3 OUT4 D94AU179B C5 0.1µF C6 47µF SVR TAB Vcc1-2 Vcc3-4 C8 0.1µF C7 2200µF C10 1µF ST-BY R1 10K R2 47K MUTE C1 14 15 12 11 22 4 13 S-GND 16 10 25 1 DIAGNOSTICS 6 20 9 8 7 5 2 3 17 18 19 21 24 23 Figure 1: Standard Test and Application Circuit TDA7385 4/12 TDA7385 Figure 2: P.C.B. and component layout of the figure 1 (1:1 scale) COMPONENTS & TOP COPPER LAYER BOTTOM COPPER LAYER TDA7385 5/12 Figure 3: Quiescent Current vs. Supply Voltage Figure 4: Quiescent Output Voltage vs. Supply Voltage Figure 5: Output Power vs. Supply Voltage Figure 6: Distortion vs. Output Power Figure 7: Distortion vs. Frequency. Figure 8: Supply Voltage Rejection vs.Frequencyby varying C6 Rg = 600Ω Vripple = 1Vrms TDA7385 6/12 Figure 9: Output Noise vs. Source Resistance Figure 10: Power Dissipation & Efficiency vs. Output Power Rg (Ω) Ptot (W) Ptot APPLICATION HINTS (ref. to the circuit of fig. 1) BIASING AND SVR As shown by fig. 11, all the TDA7385’s main sec- tions, such as INPUTS, OUTPUTS AND AC-GND (pin 16) are internally biased at half Supply Volt- age level (Vs/2), which is derived from the Supply Voltage Rejection (SVR) block. In this way no cur- rent flows through the internal feedback network. The AC-GND is common to all the 4 amplifiers and represents the connection point of all the in- verting inputs. Both individual inputs and AC-GND are con- nected to Vs/2 (SVR) by means of 100KΩ resis- tors. To ensure proper operation and high supply volt- age rejection, it is of fundamental importance to provide a good impedance matching between IN- PUTS and AC-GROUND terminations. This im- plies that C1, C2, C3, C4, C5 CAPACITORS HAVE TO CARRY THE SAME NOMINAL VALUE AND THEIR TOLERANCE SHOULD NEVER EXCEED ±10 %. Besides its contribution to the ripple rejection, the SVR capacitor governs the turn ON/OFF time se- quence and, consequently,plays an essential role in the pop optimization during ON/OFF transients. To conveniently serve both needs, ITS MINIMUM RECOMMENDED VALUE IS 10µF. + - 0.1µF C1 ÷ C4 + - 8KΩ 8KΩ 400Ω 400Ω 100KΩ 100KΩ70KΩ IN D95AU302 TOWARDS OTHER CHANNELS 10KΩ 10KΩ VS 47µF C6 0.1µF C5 SVR AC_GND Figure 11: Input/OutputBiasing. TDA7385 7/12 INPUT STAGE The TDA7385’S inputs are ground-compatible and can stand very high input signals (± 8Vpk) without any performances degradation. If the standard value for the input capacitors (0.1µF) is adopted, the low frequency cut-off will amount to 16 Hz. STAND-BY AND MUTING STAND-BY and MUTING facilities are both CMOS-COMPATIBLE. If unused, a straight con- nection to Vs of their respective pins would be ad- missible. Conventional low-power transistors can be employed to drive muting and stand-by pins in absence of true CMOS ports or microprocessors. R-C cells have always to be used in order to smooth down the transitions for preventing any audible transient noises. Since a DC current of about 10 uA normally flows out of pin 22, the maximum allowable muting-se- ries resistance (R2) is 70KΩ, which is sufficiently high to permit a muting capacitor reasonably small (about 1µF). If R2 is higher than recommended, the involved risk will be that the voltage at pin 22 may rise to above the 1.5 V threshold voltage and the device will consequently fail to turn OFF when the mute line is brought down. About the stand-by, the time constant to be as- signed in order to obtain a virtually pop-free tran- sition has to be slower than 2.5V/ms. DIAGNOSTICS FACILITY The TDA7385 is equipped with a diagnostics cir- cuitry able to detect the following events: CLIPPING in the output stage OVERHEATING (THERMAL SHUT-DOWN proximity) OUTPUT MISCONNECTIONS (OUT-GND & OUT-Vs shorts) Diagnostics information is available across an open collector output located at pin 25 (fig. 12) through a current sinking whenever at least one of the above events is recognized. Among them, the CLIPPING DETECTOR acts in a way to output a signal as soon as one or more power transistors start being saturated. As a result, the clipping-related signal at pin 25 takes the form of pulses, which are perfectly syn- cronized with each single clipping event in the music program and reflect the same duration time (fig. 13). Applications making use of this facility usually operate a filtering/integration of the pulses train through passive R-C networks and realize a volume (or tone bass) stepping down in associa- tion with microprocessor-driven audioprocessors. The maximum load that pin 25 can sustain is 1KΩ. Due to its operating principles, the clipping detec- tor has to be viewed mainly as a power-depend- ent feature rather than frequency-dependent.This means that clipping state will be immediately sig- naled out whenever a fixed power level is reached, regardless of the audio frequency. In other words, this feature offers the means to counteract the extremely sound-damaging effects of clipping, caused by a sudden increase of odd order harmonics and appearance of serious inter- modulation phenomena. Another possible kind of distortion control could be the setting of a maximum allowable THD limit (e.g. 0.5 %) over the entire audio frequency range. Besides offering no practical advantages, this procedure cannot be much accurate, as the non-clipping distortion is likely to vary over fre- quency. In case of OVERHEATING, pin 25 will signal out the junction temperature proximity to the thermal shut-down threshold. This will typically start about 2oC before the thermal shut-down threshold is VREF R Vpin 25 25 D95AU303 TDA7385 Figure 12: Diagnosticscircuit. Figure 13: Clipping Detection Waveforms. TDA7385 8/12 t t t MUTE PIN VOLTAGE Vs OUTPUT WAVEFORM Vpin 25 WAVEFORM SHORT TO GND OR TO VsD95AU304 CLIPPING THERMAL PROXIMITY ST-BY PIN VOLTAGE t Figure 14: DiagnosticsWaveforms. reached. As various kind of diagnostics information is avail- able at pin 25 (CLIPPING, SHORTS AND OVER- HEATING), it may be necessary to operate some distinctions on order to treat each event sepa- rately. This could be achieved by taking into ac- count the intrinsically different timing of the diag- nostics output under each circumstance. In fact, clipping will produce pulses normally much shorter than those present under faulty con- ditions. An example of circuit able to distinguish between the two occurrences is shown by fig. 15. STABILITY AND LAYOUT CONSIDERATIONS If properly layouted and hooked to standard car- radio speakers, the TDA7385 will be intrinsically stable with no need of external compensations CLIP DET. (TO GAIN COMPRESSOR/ TONE CONTROL) T125 D95AU305 TDA7385 + - VREF VREF1 T2 FAULT, THERMAL SHUTDOWN (TO POWER SUPPLY SECTION, µP VOLTAGE REGULATOR, FLASHING SYSTEM) + - VREF2 T1 << T2 VREF ≥ VREF1 >> VREF2 Figure 15. TDA7385 9/12 such as output R-C cells. Due to the high number of channels involved, this translates into a very remarkable components saving if compared to similar devices on the market. To simplify pc-board layout designs, each ampli- fier stage has its own power ground externally ac- cessible (pins 2,8,18,24) and one supply voltage pin for each couple of them. Even more important, this makes it possible to achieve the highest possible degree of separation among the channels, with remarkable benefits in terms of cross-talk and distortion features. About the layout grounding, it is particularly im- portant to connect the AC-GND capacitor (C5) to the signal GND, as close as possible to the audio inputs ground: this will guarantee high rejection of any common mode spurious signals. The SVR capacitor (C6) has also to be connected to the signal GND. Supply filtering elements (C7, C8) have naturally to be connected to the power-ground and located as close as possible to the Vs pins. Pin 1, which is mechanically attached to the de- vice’s tab, needs to be tied to the cleanest power ground point in the pc-board, which is generally near the supply filtering capacitors. TDA7385 10/12 Flexiwatt25 DIM. mm inchMIN. TYP. MAX. MIN. TYP. MAX. A 4.45 4.50 4.65 0.175 0.177 0.183 B 1.80 1.90 2.00 0.070 0.074 0.079 C 1.40 0.055 D 0.75 0.90 1.05 0.029 0.035 0.041 E 0.37 0.39 0.42 0.014 0.015 0.016 F (1) 0.57 0.022 G 0.80 1.00 1.20 0.031 0.040 0.047 G1 23.75 24.00 24.25 0.935 0.945 0.955 H (2) 28.90 29.23 29.30 1.138 1.150 1.153 H1 17.00 0.669 H2 12.80 0.503 H3 0.80 0.031 L (2) 22.07 22.47 22.87 0.869 0.884 0.904 L1 18.57 18.97 19.37 0.731 0.747 0.762 L2 (2) 15.50 15.70 15.90 0.610 0.618 0.626 L3 7.70 7.85 7.95 0.303 0.309 0.313 L4 5 0.197 L5 3.5 0.138 M 3.70 4.00 4.30 0.145 0.157 0.169 M1 3.60 4.00 4.40 0.142 0.157 0.173 N 2.20 0.086 O 2 0.079 R 1.70 0.067 R1 0.5 0.02 R2 0.3 0.12 R3 1.25 0.049 R4 0.50 0.019 V 5° (Typ.) V1 3° (Typ.) V2 20° (Typ.) V3 45° (Typ.) (1): dam-bar protusion not included (2): molding protusion included H3 R4 G V G1 L2 H1 H F M1 L FLEX25ME V3 O L3 L4 H2 R3 N V2 R R2 R2 C B L1 M R1 L5 R1 R1 E D A V V1 V1 OUTLINE AND MECHANICAL DATA TDA7385 11/12 Information furnished is believed to be accurate and reliable. However, STMicroelectronics assumes no responsibility for the consequences of use of such information nor for any infringement of patents or other rights of third parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of STMicroelectronics. Specification mentioned in this publication are subject to change without notice. This publication supersedes and replaces all information previously supplied. STMicroelectronics products are not authorized for use as critical components in life support devices or systems without express written approval of STMicroelectronics. The ST logo is a registered trademark of STMicroelectronics  1999 STMicroelectronics – Printed in Italy – All Rights Reserved STMicroelectronics GROUP OF COMPANIES Australia - Brazil - China - Finland - France - Germany - Hong Kong - India - Italy - Japan - Malaysia - Malta - Morocco - Singapore - Spain - Sweden - Switzerland - United Kingdom - U.S.A. http://www.st.com TDA7385 12/12