AN5270

AN5270 PANASONIC | Alldatasheet

Document overview

• Manufacturer or author: Provided By ALLDATASHEET.COM(FREE DATASHEET DOWNLOAD SITE)
• PDF pages: 9

Technical content

4.3 W · 1(8W ) Power Amplifier with Volume Control and Tone Control

The AN5720 is an integrated circuit designed for 4.3 W(8 W ) power amplifier with volume control and tone control. n Features

• DC volume control : 0 to 5 V
• DC tone control : 0 to 5 V
• 9-lead single-in-line plastic package with fin n Block Diagram n Pin Descriptions HSIP009-P-0000 Unit : mm Pin No. Pin Name 1V CC1

2 Sound input

3 Low frequency input

4 Volume control

5 Tone control

6 Ripple filter

7 Ground

8 Sound output

Note) Pins 2 and 4 are weaker in protection against positive surge than the other pins. It is necessary to pay attention during application use. V CC1 In 2 LF 3 V ol-ctl.4 Tone-ctl.5 RF 6 GND 7 Out 8 V CC2 Preamp. V olume control Tone control f3.3–0.10.1–0.05 5.6–0.25 –0.25 1.7 1.7–0.25 0.45 +0.1–0.05 3.75–0.25 0.5 –0.1 1.2 –0.25 2.54 15.0 19.9–0.1 18.3–0.25 5.8–0.25 1.5–0.25 –0.3 –0.25 22.3–0.3

AN5270 ICs for Audio Common Use n Absolute Maximum Ratings Parameter Symbol Ratings Unit Supply voltage V CC1 (V1-7)1 4 V V CC2 (V9-7)2 6 Circuit voltage V 2-7 0 to V9-7 V 3-7 0 to V9-7 V 4-7 0 to V1-7 V 5-7 0 to V1-7 Supply current I CC1 15 mA ICC2 2A Circuit current *3, 4 I8 -1.7 to +1.7 A PP Power dissipation *2 PD 1.6 W Operating ambient temperature *1 Topr -20 to +70 °C Storage temperature *1 Tstg -55 to +150 °C n Recommended Operating Range Parameter Symbol Range Unit Operating supply voltage range V CC1 11 to 13 V V CC2 15 to 24 Note) Do not apply a current or voltage from the external to the terminals that are not described above. *1 :T a = 25 °C, excluding parameters regarding ambient temperature and storage temperature. *2 :T a = 70 °C, the IC is mounted on PCB, without external heat sink. *3 : For circuit currents, '+' denotes current flowing into the IC, and '-' denotes current flowing out of the IC. *4 : As the output Pin8 does not have over current protection circuit incorporated, therefore please take precaution not to short the output pin to either VCC or GND.

ICs for Audio Common Use AN5270 n Electrical Caracteristics at VCC1 = 12 V, VCC2 = 18 V, f = 1 kHz, Ta = 25 °C, RL = 8 W , Vol. = max., Tone = max. Parameter Symbol Conditions Min Typ Max Unit Quiescent current 1 I TOT1 No input signal 7 10 13 mA Measure VCC1 current Quiescent current 2 I TOT2 No input signal 20 28 48 mA Measure VCC2 current Output DC bias V ODC No input signal 7.2 8.3 9.4 V Measure Pin8 DC Voltage gain G V V O = 1 Vrms, GV = 20 log(VO / VIN) 2 83 03 2d B Total harmonic distortion THD V O = 1 Vrms, BPF : 400 Hz to 30 kHz ¾ 0.5 1.0 % Max. output power Pomax THD = 10 %, PO = VO 2 / RL 4.0 4.3 ¾ W Attmax = 20 log [VO(vol. = max.) / VO(vol. = min.)] Tone variable range DG TC f = 10 kHz, fix VIN where 18 20 ¾ dB V O(tone = max.) = 1 Vrms Tone = max. fi min. DG TC = 20 log [VO(tone = max.) / VO(tone = min.)] n Application Circuit Example V CC1 1 In 2 LF V ol-ctl.4 Tone-ctl.5 RF 6 GND 7 Out 8 V CC2 5.1kW AN5270 AN78M12 GND 10kW VR 33kW 24kW AV SW 100W External audio in 3.3mF 33mF 33mF Ext TV 0.039 mF 470 mF 47mF 100mF 22mF 2200mF 47mF 12V AN78M05SIF-IC 33mF 100kW 9kW 30kW 10kW VR 1kW 33mF Det. out 18V Power supply Note) Design considerations for shock noise prevention. : In the application of the IC, please adopt the above power supply configuration whenever possible. Where this is not possible, then it is better to ensure that V CC1 should start up first before the onset of VCC2 , in order to prevent power-on shock noise. Similarly, please ensure that VCC2 declines faster than VCC1 , in order to prevent power-off shock noise.

AN5270 ICs for Audio Common Use n Technical Information

• Characteristic curve chart PD ¾ Ta Area of safe operation
• Structure of pre-amp. stage Explanation of gain notations : G T : Gain of tone-amp. (treble-amp.) G F : Gain of flat-response amp. G B : Gain of bass-amp. G L1 : Gain at point 1 with respect to VIN. G L2 : Gain at point 2 with respect to VIN. G P : Gain of power stage. G pre : Gain of pre-amp. stage. Volume-control Output G P (25 dB)G B V IN G F Tone-control Pre-amp. stage Fig. Simplified structure of AN5270 pre-amp. stage G T Ci 33 pF G 1 kW LF input Input 2.8 kW 2.8 kW Point2 G L2 Point1 G L1 5.6 kW 47 kW C2 C1 Power stage

1 No heat sink

2 5.5 · 5.0 cm2 Al board (t = 1 mm) 3 7.5 · 7.5 cm2 Al board (t = 1 mm)

4 Infinity heat sink

Power dissipation PD (W ) Ambient temperature Ta (°C) 40 60 80 100 120 140 2.5 3.36 4.14 10.4 6.65 Pmax < Tjmax - Ta R th 2.63 2.15 1.6 0.01 1 5 10 26 50 0.02 0.05 0.1 0.5 1.7 100 IC (A ) V CE (V) 10 ms single pulse, free air 25 °C 70 °C

ICs for Audio Common Use AN5270 n Technical Information (continued)

• Structure of pre-amp. stage (continued) G F amp., the flat-amp., amplifies the signal equally for all frequencies in the range of 20 Hz to 70 kHz. G T amp., the treble or tone-amp., has an internal LPF connected to its inverting input. The non-inverting input of GT amp. is connected to the input signal. Thus, the output of GT passes only the upper range of frequencies (cut-off frequency = 2.5 kHz). G B amp., the bass-amp., amplifies the lower range of frequencies. Its cut-off frequency is determined by R1· C1. If LF pin is left open, then GB amp. has no effect on the overall frequency response.
• Gain calculation General formula for gain of pre-amp. is (when vol. = max., tone = max.) : G pre = GL1 · (GF + GT) - GB · GL2 By vector analysis as shown in fig. Vector diagram of Gpre, G V [dB] = Gpre + GP G V [dB] = 20 log Ö[GL1 · (GF + GT) - GB · GL2 · cosq]2 + (GB · GL2 · sinq)2 + GP where G L1 = 0.5 G F = 1.3 G B = 5.4 ì 0 for (100 Hz) G T =í 1.3 for (1 kHz) î 2.5 for (10 kHz) G P = 25 dB G B » Z3 · 0.848 Z3 + R1 Z3 = 6600 Ö1 + (2pf · C1 · 6600)2 q= - tan-1 (2pf · C1 · 6600) Note) *1 : This is the response if LF pin is open (i.e. R1 open). q G pre G B · GL2 Fig. Vector diagram of Gpre G L1 · (GF + GT) G V G1 : Gain at 100 Hz G2 : Gain at 1 kHz G3 : Gain at 10 kHz f 1 : High frequency cut-off when Pin3 is open. f2 : Low frequency cut-off Tone = max. -3 dB Tone = min. Fig. Frequency response of AN5270 f2 1 kHz 10 kHzf1 f100 Hz -3 dB

AN5270 ICs for Audio Common Use R1(W ) C1(F) Actual Gain(dB)* f2(Hz) DG TC (dB) G1(100 Hz) G2(1 kHz) G3(10 kHz) ¥¾ 24.0 26.0 30.0 ¾ 14.0 n Technical Information (continued)

• Cut-off frequencies f1 = 1 = 2.5 kHz where G = 40 times, Ci = 33 pF, R1 = 47 kW2p · G · Ci · Ri f2 = 1 = 530 Hz if R1 = 3 kW , C2 = 0.1 mF2p · R1 · C1
• Summary of frequency characteristics for typical values of R1 and C1 Note) * : Tone = max. Table. Tabulated summary of frequency characteristics of AN5270.
• Volume control The volume control range is 0 to 5 V. This range is adopted so as to simplify the pull-up of typical PWM output from micro-computer IC. The following simplified PWM output configuration is suggested : The high input impedance of the volume control pin makes the input current extremely small, so that it is not necessary to have an external buffer at the PWM output. Configuration A : 12 kWR5 2.2 mFC4 5 V PWM output Micro- computer IC 18 kW Fig. V olume control interface circuit for AN5270 300 W 300 W V olume control Treble control

ICs for Audio Common Use AN5270 n Technical Information (continued)

• Volume control (continued) Alternative responses of volume control may be obtained by addition of a diode across the resistor R4.
• Tone control The tone cotrol range is 0 to 5 V. Please adopt the same PWM configration as suggested for the volume control. The variable range of tone control is about 20 dB, depending on the values of R1 · C1 components that are connected to Pin3. Internally, there is a LPF formed by Ri = 47 kW and a Miller capacitor which is formed by Ci = 33 pF and the gain amplifier G = 40. The cut-off frequency is thus : 1 = 2.5 kHz2p · G · Ci · Ri To achieve a rich deep-bass effect, the tone control should be adjusted to minimum (0 V). To achieve a bright treble effect, the tone control should be adjusted to maximum.
• VCC requirement V CC1 should be fixed at 12 V. Achieve best performance by obtaining this supply from a 12 V voltage regulator output. 12 kW 2.2 mF 18 kW Configuration B : Config. BA C 12 kW 2.2 mF 18 kW 10 kW Configuration C : Fig. V olume characteristics of AN5270 V olume attenuation 0 0.6 V V olume DC Pin4 (V) 5 V

AN5270 ICs for Audio Common Use n Technical Information (continued)

• Power-on/off pop-noise elimination In most TV applications, it is observed that there is a short period of delay from power-on to the onset of sound. The purpose of power-on mute is to eliminate any unpleasant 'pop' noise (caused by transients) by effectively muting the power amplifier. In this IC, an internal mute is incorporated at the instant of power-on and power-off. The length of mute time depends on the value of the ripple filter condenser at Pin6. In the following diagram, the value of the condenser connected to RF pin (Pin6) is 47 mF. (The above timing diagram is based on the evaluation circuit that is given in the product specification. Actual chasis performance may differ due to differences in power supply and external components.) The internal mute pulse will force the volume to minimum by grounding Pin4 momentarily. In most chasis, it is also common to implement externally the audio defeat feature by forcing Pin4 to ground momentarily, for the purpose of power-on/off as well as during channel switching. Should the internal mute be insufficient, it is recommended that the external audio defeat be used. V CC2 Pin9 18 V V CC1 Pin1 12 V V olume Pin4 Output Pin8 5 V 470 ms Internal mute-pulse Fig. Power on/off typical timing characteristics of AN5270 1.2 s 220 ms 170 ms 270 ms

ICs for Audio Common Use AN5270 n Technical Information (continued)

• Power-off pop-noise countermeaasure (for study consideration only) To prevent power-off shock noise, please ensure that VCC2 (18 V) declines faster than VCC1 (12 V). In addition, to ensure that VCC1 variation will not cause any 'pop' , one suggested countermeasure is to connect a condenser between Pin6 and Pin9 (e.g. 47 mF, use non-polarity type if possible). This effect of Cpop is to discharge C6 gradually as soon as power is switched off. However, it must be noted that the necessity of this countermeasure is dependent upon the set design and other timing considerations.
• THD improvement (for study consideration only) Instead of connecting the negative terminal of C6 to ground, when that terminal is connected to Pin1, it is noticed that THD is improved considerably. RF Cpop 47 mF NP 2200 mF V CC2 Fig. One suggested counter-measure against power-off 'pop' for AN5270. 47 mF 1 6 47 mF Fig. THD improvement circuit.