AN7198Z

AN7198Z PANASONIC

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Technical content

Dual 20 W BTL Power IC for Car Audio n Overview The AN7198Z is an audio power IC developed for the sound output of car audio (Dual 20 W). A capacitor and a resistor between the output pin and GND to stop oscillation are built-in so that a space saving of set is possible. Also, it is incorporates an industry's first superior muting circuit which is free from shock noise, so that a shock noise design under the set transient condition can be made easily when the muting circuit is used together with its standby function. In addition, it is incorporating various protective cir- cuits to protect the IC from destruction by GND-open short circuit to GND and power supply surge which are the important subjects of power IC protection, and the IC will largely contribute to a high reliability design of equip- ment. n Features

• Built-in various protection circuits (Realizing high breakdown voltage against destruction) Power supply surge breakdown voltage of 80 V or more Ground-open breakdown voltage of 16 V or more
• Built-in standby function (Free from shock noise at STB-on/off)
• Built-in muting function Free from shock noise at mute-on/off Adapting attenuator method, so that abnormal sound due to waveform deformation is not generated Attack time, recovery time of 50 ms or less
• Reduction in external components No capacitors and resistors for oscillation stop are unnecessary It eliminates the need for NF and BS electrolytic capacitors Muting function is unnecessary Power supply choke coil is unnecessary
• Provided with beep sound input pin
• High sound quality design n Applications
• Car audio HZIP015-P-0745A 18.00±0.30 13.50±0.30 f3.60±0.10 10.0±0.30 11 5 4.00±0.20 1.50±0.10 0.50 +0.20 –0.10 (0.61) (2.54) 0.25 +0.15 –0.05 R0.55 3.25±0.10 13.25±0.30 18.95±0.50 15.65±0.50 1.27 (1.80) (1.95) 19.00±0.30 19.30±0.30 2.40±0.50 Unit: mm

AN7198Z ICs for Audio Common Use n Pin Description n Absolute Maximum Ratings Parameter Symbol Ratings Unit Supply voltage *2 V CC 25 V Peak supply voltage *3 V surge 60 V Supply current I CC 9.0 A Power dissipation *4 PD 59 W Operating ambient temperature *1 Topr - 30 to + 85 °C Storage temperature *1 Tstg - 55 to + 150 °C Note) *1: Ta = 25°C except operating ambient temperature and storage temperature. *2: Without signal *3: Time = 0.2 s *4: Ta = 85°C n Block Diagram Pin No. Description

1 Power supply

2 Ch.1 output ( +) 3 Grounding (output ch.1) 4 Ch.1 output ( -)

5 Standby

6 Ch.1 input

7 Muting

8 Grounding (board)

Pin No. Description

9 Grounding (input)

10 Beep sound input

11 Ch.2 input

12 Ripple filter

13 Ch.2 output ( -) 14 Grounding (output ch.2) 15 Ch.2 output ( +) Ref. Protection Cct. Att.Con. Att Att Att Att

1 V CC8GND(Sub)

GND (Input) Beep In ch.1 In ch.2 In Ripple Filter Standby Mute ch.1 GND ch.2 GND ch.1 Out (-) ch.1 Out (+) ch.2 Out (-) ch.2 Out (+)

ICs for Audio Common Use AN7198Z n Electrical Characteristics at VCC = 13.2 V, f = 1 kHz, Ta = 25°C Parameter Symbol Conditions Min Typ Max Unit Quiescent current I CQ V IN = 0 mV, RL = 4 W¾ 150 250 mA Standby current I STB V IN = 0 mV, RL = 4 W¾ 11 0 mA Output noise voltage *1 V NO R g = 10 kW , RL = 4 W¾ 0.18 0.5 mV[rms] Voltage gain 1 G V1 V IN = 40 mV, RL = 4 W 32 34 36 dB Total harmonic distortion 1 THD 1 V IN = 40 mV, RL = 4 W¾ 0.05 0.4 % Maximum output power 1 P O1 THD = 10% , RL = 4 W 16 18.5 ¾ W V CC = 14.4 V, RL = 4 W ¾ 22.0 ¾ W Ripple rejection ratio *1 RR R L = 4 W , Rg = 10 kW , Vr = 1 V[rms] 60 65 ¾ dB fr = 1 kHz Channel balance CB V IN = 40 mV, RL = 4 W¾ 01d B Cross-talk *1 CT V IN = 40 mV, RL = 4 W , Rg = 10 kW 60 79 ¾ dB Output offset voltage V Off R g = 10 kW , RL = 4 W- 250 0 250 mV Muting effect *1 MT V O = 1 W, RL = 4 W 70 86 ¾ dB Input impedance Z i V IN = – 0.3 VDC 24 30 36 k W Voltage gain 2 G V2 V IN = 40 mV, RL = 2 W 32 34 36 dB Total harmonic distortion 2 THD 2 V IN = 40 mV, RL = 2 W¾ 0.08 0.5 % Maximum output power 2 P O2 THD = 10% , RL = 2 W 16 28 ¾ W Shock noise *2 V S R L = 4 W , Rg = 10 kW , VMUTE = 5 V -100 0 100 mV[p-0] V STB = on/off, 50 Hz HPF-on Total harmonics distortion 3 THD3 V IN = 20 mV, fIN = 20 kHz ¾ 0.10 0.5 % R g = 10 kW , RL = ¥ Note) *1: Measurement using a bandwidth 15 Hz to 30 kHz (12 dB/OCT) filter. *2: For VSTB = on/off change over the standby terminal by the voltage of 0 V and 5 V at the time shown below. Standby terminal voltage n Recommended Operating Range Parameter Symbol Ratings Unit Supply voltage V CC 8.0 to 18.0 V 5 V 0 V 500 ms 500 ms

AN7198Z ICs for Audio Common Use Pin No. Equivalent circuits Description DC voltage 1 ¾ Supply voltage connection pin 13.2 V Power supply connection pin 2 Ch.1 output pin ( +) 6.3 V Ch.1 positive-phase output pin 3 ¾ GND (Output) 0 V Grounding pin for ch.1 output 4 Ch.1 output pin ( -) 6.3 V Ch.1 inverted-phase output pin ɹ

5 Standby control pin

Threshold voltage approx. 2.1 V 6 Ch.1 input pin 0 mV to 10 mV Ch.1 input signal applied pin Input impedance 30 kW n Terminal Equivalent Circuits 15 kW AN7198Z: 600 W AN7199Z: 300 W Pre-amp. V REF = 6.3 V Drive Circuit Drive Circuit 15 kW AN7198Z: 600 W AN7199Z: 300 W Pre-amp. V REF = 6.3 V Drive Circuit Drive Circuit 2 kW 10 kW approx. 15 mA approx. 15 mA200 W 30 kW 600 W

ICs for Audio Common Use AN7198Z Pin No. Equivalent circuits Description DC voltage

7 Mute control pin ¾

Threshold voltage approx. 2.1 V 8 ¾ GND (substrate) 0 V Substrate 9 ¾ GND (input) 0 V Grounding pin for input 10 Beep sound input pin 2.1 V Beep sound signal input pin Input impedance 15.3 kW 11 Ch.2 input pin 0 mV to 10 mV Ch.2 input signal applied pin Input impedance 30 kW 12 Ripple filter pin 13.0 V Output current 3 mA to 10 mA n Terminal Equivalent Circuits (continued) 200 W R nf 15 kW R nf 15 kW R nf 15 kW7.8 kW R nf R nf AN7198Z: 600W AN7199Z: 300W 15 kW V REF = 6.3 V V REF = 6.3 V approx. 15 mA approx. 15 mA200 W 30 kW 600 W 20 kW 15 kW 1.7 mA 350 mA V CC

AN7198Z ICs for Audio Common Use Pin No. Equivalent circuits Description DC voltage 13 Ch.2 output pin ( -) 6.3 V Ch.2 inverted-phase output pin 14 ¾ GND (output) 0 V Grounding pin for ch.2 output 15 Ch.2 output pin ( +) 6.3 V Ch.2 positive-phase output pin n Terminal Equivalent Circuits (continued) 15 kW AN7198Z: 600 W AN7199Z: 300 W Pre-amp. V REF = 6.3 V Drive Circuit Drive Circuit 15 kW AN7198Z: 600 W AN7199Z: 300 W Pre-amp. V REF = 6.3 V Drive Circuit Drive Circuit n Usage Notes 1. Always attach an outside heat sink to use the chip. In addition, the outside heat sink must be fastened onto a chassis for use. 2. Connect the cooling fin to GND potential. 3. Avoid short-circuit to VCC and short circuit to GND, and load short-circuit. There is a danger of destruction under a special condition. 4. The temperature protection circuit will be actuated at Tj = approx. 150°C, but it is automatically reset when the chip temperature drops below the above set level. 5. The overvoltage protection circuit starts its operation at VCC = approx. 20 V. 6. Take into consideration the heat radiation design particularly when VCC is set high or when the load is 2 W . 7. When the beep sound function is not used, open the beep sound input pin (pin10) or connect it to pin 9 with around 0.01 mF capacitor. 8. Connect only pin 9 (ground, signal source) to the signal GND of the amplifier in the previous stage. The characteristics such as distortion, etc. will be improved.

ICs for Audio Common Use AN7198Z n Technical Information 1. PD ¾ Ta Curves of HZIP015-P-0745A PD ¾ Ta 120 113.6 100 59.5 40.340 30.5 20.5 11.3 1.8 0 25 50 75 100 125 150 Ambient temperature Ta (°C) Power dissipation PD (W) Infinity heat sink 1°C/W heat sink 2°C/W heat sink 3°C/W heat sink 5°C/W heat sink 10°C/W heat sink Without heat sink R th (j-c) = 1.1°C/W R th (j-a) = 68.3°C/W 2. Main Characteristics 0 5 10 15 20 25 Supply voltage VCC (V) Output voltage PO (W) R L = 2 W R L = 4 W f = 1 kHz THD = 10%

400 Hz HPF

R g = 10 kW 0 5 10 15 20 Output power (1-channel) PO (W) Consumption power PC (W) Supply current ICC (A) V CC = 13.2 V f = 1 kHz R g = 10 kW PC (RL = 2 W) PC (RL = 4 W) ICC (RL = 2 W) ICC (RL = 4 W) PO ¾ VCC PC , ICC ¾ PO

AN7198Z ICs for Audio Common Use n Technical Information (continued) 2. Main Characteristics (continued) 0.10 1.00 10.00 100.00 0.01 0.10 1.00 10.00 1 10 100 1 000 Input voltage VIN (mV[rms]) Output power PO (W) Total harmonic distortion THD (% ) THD 100 Hz 1 kHz THD 10 kHz V CC = 13.2 V f = 1 kHz R L = 4 W R g = 10 kW PO 0.10 1.00 10.00 100.00 0.01 0.10 1.00 10.00 1 10 100 1 000 Input power VIN (mV[rms]) Output power PO (W) Total harmonic distortion THD (% ) THD 100 Hz 1kHz THD 10 kHz V CC = 13.2 V f = 1 kHz R L = 2 W R g = 10 kW PO 10 100 1 000 10 000 100 000 P O (2 W ) PO (4 W ) G V (2, 4 W ) Frequency f (Hz) Voltage gain GV (dB) Output power PO (W) R g = 10 kW V CC = 13.2 V PO = 1 W THD = 10% R L = 2, 4 W 10 100 1 000 10 000 100 000 R L = 4 W R L = 2 W Frequency f (Hz) Total harmonic distortion THD (%) 0.01 0.10 1.00 10.00 V CC = 13.2 V PO = 1 W R L = 2, 4 W R g = 10 kW PO , THD ¾ VIN (RL = 4 W )P O , THD ¾ VIN (RL = 2 W ) G V , PO ¾ f THD ¾ f G V , THD ¾ VCC ICQ , ISTB ¾ VCC 27 0.5 29 1 31 1.5 33 2 35 2.5 37 3 39 3.5 41 4 43 4.5 45 5 0 5 10 15 20 25 Supply voltage VCC (V) V oltage gain GV (dB) Total harmonic distortion THD (%) V IN = 40 mV[rms] f = 1 kHz R L = 2, 4 W R g = 10 kW G V (RL = 4, 2 W ) THD (R L = 4, 2 W ) 20 1 40 2 60 3 80 4 100 5 120 6 140 7 160 8 180 9 200 10 0 5 10 15 20 25 Supply voltage VCC (V) Quiescent current ICQ (mA) Standby current ISTB (mA) R L = 4 W Both channel input R g = 10 kW ICQ ISTB

ICs for Audio Common Use AN7198Z n Technical Information (continued) 2. Main Characteristics (continued) V NO ¾ VCC V NO ¾ Rg RR ¾ VCC RR ¾ Vr 0.0 0.5 1.0 0 5 10 15 20 Supply voltage VCC (V) Output noise voltage VNO (mV[rms]) R L = 4 W R g = 10 kW Flat DIN Audio Filter 0.0 0.5 1.0 Input impedance Rg (W ) Output noise voltage VNO (mV[rms]) V CC = 13.2 V R L = 4 W R g = 10 kW Flat DIN Audio Filter 10 100 1 000 10 000 100 000 0 5 10 15 20 25 Supply voltage VCC (V) Ripple rejection ratio RR (dB) R L = 4 W R g = 10 kW fr = 1 kHz V r = 1 V[rms] channel 2 channel 1 Power supply ripple voltage Vr (mV[rms]) Ripple rejection ratio RR (dB) V CC = 13.2 V R L = 4 W R g = 10 kW fr = 1 kHz 1 10 100 1 000 10 000 channel 2 channel 1 RR ¾ fr CT ¾ VCC Power supply ripple frequency fr (Hz) Ripple rejection ratio RR (dB) V CC = 13.2 V R L = 4 W R g = 10 kW fr = 1 kHz V r = 1 V[rms] channel 1 channel 2 10 100 1 000 10 000 0 5 10 15 20 25 Supply voltage VCC (V) Cross-talk CT (dB) PO = 1 W f = 1 kHz R L = 4 W R g = 10 kW channel 1 channel 2

AN7198Z ICs for Audio Common Use n Technical Information (continued) 2. Main Characteristics (continued) CT ¾ VIN CT ¾ f MT ¾ VCC MT ¾ VIN MT ¾ f MT ¾ VMUTE 1 10 100 1 000 Input voltage VIN (mV[rms]) Cross-talk CT (dB) channel 1 channel 2 V CC = 13.2 V f = 1 kHz R L = 4 W R g = 10 kW 10 100 100 000 Frequency f (Hz) Cross-talk CT (dB) 1 000 10 000 channel 1 channel 2 V CC = 13.2 V V IN = 40 mV[rms] R L = 4 W R g = 10 kW 100 110 0 5 10 15 20 25 Supply voltage VCC (V) Muting effect MT (dB) PO = 1 W f = 1 kHz R L = 4 W R g = 10 kW 100 0 10 100 1 000 10 000 Input voltage VIN (mV[rms]) Muting effect MT (dB)V CC = 13.2 V f = 1 kHz R L = 4 W R g = 10 kW 100 110 10 100 1 000 10 000 100 000 Frequency f (Hz) Muting effect MT (dB) V CC = 13.2 V V IN = 40 mV[rms] R L = 4 W R g = 10 kW 01 5 Mute voltage VMUTE (V) Muting effect MT (dB) 2 3 4 channel 1 V CC = 13.2 V PO = 1 W f = 1 kHz R L = 4 W R g = 10 kW channel 2

ICs for Audio Common Use AN7198Z n Technical Information (continued) 2. Main Characteristics (continued) ICQ ¾ VSTB V offset ¾ VCC 100 120 140 160 180 200 0 1 2345 Standby voltage VSTB (V) Quiescent circuit current ICQ (mA) V CC = 13.2 V R L = 4 W R g = 10 kW -250 -200 -150 -100 -50 100 150 200 250 0 5 10 15 20 Supply voltage VCC (V) Output offset voltage Voffset (mV) R L = 4 W R g = 10 kW channel 1 channel 1 mute on channel 2 mute on channel 2 3. Application note 1) Standby function (1) The power can be turned on or off by making pin 5 (standby terminal) high or low. (2) The standby terminal has threshold voltage of approx. 2.1 V, however, it has temperature dependency of approx. -6 mV/°C. The recommended range Table 1 of use is shown in Table 1. (3) The internal circuit of standby termial is as shown in Figure 1. When the standby terminal is high, the current approximately expressed by the following equation will flow into the circuit. I STB = V STB -2.7 V [mA]10 kW Figure 1 (4) A power supply with no ripple component should be used for the control voltage of standby terminal. 2 kW 4 kW 10 kW5 V 0 V

5 RF Protection

Terminal state Terminal voltage Power Open 0 V Standby state Low 0 V to 1.0 V Standby state High Higher than 3 V Operating state

AN7198Z ICs for Audio Common Use 10 kW 30 kW 200 W6 600 W 15 mA 0.01 mF 1 mF 15 mA Attenuator to power Input signal n Technical Information (continued) 3. Application note (continued) 2) Output line noise countermeasures (1) In order to increase the oscillation allowance, it is unnecessary to use a capacitor and a resistor between each output terminal and GND. However, when inserting the capacitor for counter- measures against output line noise between the output terminal and GND, insert a resistor of approx. 2.2 W in series as shown in Figure 2. The oscillation may occur if only capacitor is used. Use it after giving a sufficient evaluation. (2) The use of polyester film capacitor having a little fluctuation with temperature and frequency is recommended as the capacitor for countermeasures against output line noise. 3) Input terminal (1) The reference voltage of input terminal is 0 V. When the input signal has a reference voltage other than 0 V potential, connect a coupling capacitor (of about several mF) for DC component Figure 2 cut in series with the input terminal. Check the low-pass frequency characteristics to determine the capacitor value. (2) 10 kW or less of signal source impedance R g can reduce the output end noise voltage. (3) The output offset voltage fluctuates when the signal source impedance Rg is changed. A care must be taken in the case of using the circuit by directly connecting a volume control to the input terminal. In such a case, the use of coupling capacitor is recommended. (4) If a high frequency signal from tuners enters the input terminal as noise, insert a capacitor of approx. 0.01 mF between the input terminal and input GND. When a high frequency signal is inputted, malfunction in protective circuits may occur. Figure 3 4) Ripple filter (1) In order to suppress the fluctuation of supply voltage, connect a capacitor of approx. 33 mF between RF terminal (pin 12) and GND. (2) Relation between RR (Ripple Rejection Ratio) and a capacitor. The larger the capacitance of the ripple filter is, the better the ripple rejection ratio becomes. (However, there is almost no difference if the capacitance is 10 mF or more.) 2.2 W 0.01 mF to 0.1 mF 2, 4 13, 15 3, 14 to speaker

AN7198Z ICs for Audio Common Use n Technical Information (continued) 3. Application note (continued) 6) Cooling fin (1) The cooling fin is not connected with GND terminal by using Au wire. Only pin 8 is electrically connected through the substrate. (2) Always attach an outside heat sink to the cooling fin. The cooling fin must be fastened onto a chassis for use. Otherwise, IC lead failure may occur. (3) Do not give the cooling fin any potential other than the GND potential. Otherwise, it may cause breakdown. (4) Connection of the cooling fin with GND can reduce the incoming noise hum. (It is unnecessary to connect with GND in use, but connect it with the power GND when the cooling fin is connected with GND) 7) Shock noise (1) STB on/off Turn on the mute circuit when switching over to the standby. No shock noise is released when the mute on state. However, the changeover switch of the standby terminal may make a slight shock noise. In such a case, insert a capacitor of approx. 0.01 mF between the standby terminal and GND. (2) Mute on/off No shock noise is released. Refer to the section on the mute function. 8) Mute function (1) The mute-On/Off is possible by making pin 7 (the muting terminal) high or to low. (2) The muting circuit is as shown in Figure 7. The amplifier gain including attenuator block is given in the following equation: G V = I1

• 50I2 Original gain From the above equation, the amplifier gain can be made as 0 time by setting I1 at 0 mA at muting. (3) The threshold voltage of VMUTE is as follows: Mute-off approx. 1 V or less Mute-on approx. 3 V or more 200 W 722 kW5 V 0 V 1 mF I2I1 I2I1 I1 = approx. 120 mA I2 = approx. 120 mA Output stageInput Output stage Attenuator block V MUTE Mute/off Mute/on Figure 7

ICs for Audio Common Use AN7198Z n Technical Information (continued) 3. Application note (continued) 8) Mute function (continued) (4) Attack time and recovery time can be changed by the external CR of pin 7. For recommended circuits (Figure 7 22 kW , 1 mF), the above mentioned times are as follows: Attack time: Approx. 30 ms Recovery time: Approx. 40 ms However, the control voltage of V MUTE is assumed to be 5 V. When it is not directly controlled by microcomputer (5 V), (such as 13.2 V separate power supply), it is necessary to change CR values because the above times change. (5) When the attack time and recovery time are set at 20 ms or less, pay attention to the IC with larger output offset because it may release the shock noise. 9) Voltage gain The voltage gain is fixed at 34 dB for the AN7198Z, and 40 dB for the AN7199Z. It is not possible to change those values by the addition of an external resistance. 10) Beep sound input function (1) The application circuit example when using the beep sound input is shown in Figure 8. Connect the beep signals from the microcomputer to pin 10 via the capacitor C1 for DC cut and the resistor R1 for voltage gain adjustment. (2) The voltage gain of beep sound terminal is approx. -6.2 dB. The setting value of Figure 8 becomes approx. -19.7 dB (f = 1 kHz). (3) The beep sound is outputted to the output terminals, pin 2 and pin 15.R nf G VBEEP = 2 · GVA 1/jw C1 +R1 +7.8 K+ 15 k+R nf Figure 8 15 kW 15 kW R nf R nf 47 kW 7.8 kW G VA G VAV REF = 6.3 V V REF = 6.3 V 0.022 mF R1 Beep input R nf G VA AN7198Z 600 W 28 dB AN7199Z 300 W 34 dB

1. Application note (continued)

even larger capacitor or insert a 2200 mF capacitor into each IC. The best sound quality can be obtained by inserting a 2200 mF capacitor near the terminal of each IC. the standby terminal is twice as large as the current which is described in 1) Standby function. An abnormal operation does not occur even if the muting terminals are short-circuited with each other. 1/2 time respectively, the time constant value becomes as same as the value when one IC is used. an abnormal state in using two ICs). Even if the beep sound input terminals are short circuited each other, that does not result in an abnormal operation. However, if there is a temperature difference between ICs, there may be a fluctuation of the output offset. In order to avoid such a phenomenon, connect the ICs with each other through a resistor (47 kW ). Even if the ripple filter terminals are short circuited each other, that does not result in an abnormal operation. circuit after connecting a capacitor (33 mF) to each IC. condition. Avoid misuse and erroneous connection of the circuit. waveform as shown in Figure 11 is evaluated. The withstanding capability against power supply surge is 80 V for the AN7198Z/99Z.

10 W –1% 40 W

1 W –1% 20 W

Figure 10. Power supply surge test circuit Figure 11. Surge waveform

AN7198Z ICs for Audio Common Use n Technical Information (continued) 3. Application note (continued) 12) Precautions on misuse (continued) (1) Destruction mode for the AN7198Z/99Z The AN7198Z/99Z are the power ICs with high breakdown withstanding voltage but it has been found that the destruction occurs under special conditions.

• GND-open short-circuit to ground. Short-circuit the output terminal to the GND terminal of power supply when GND terminal of the IC is open, or a short-circuiting is made to GND when the GND terminal of the IC is over 0.7 V higher than the short- circuited output terminal. At that time, if V CC = 16 V or more and a voltage is also applied to STB terminal, then the destruction occurs.
• The plus and minus side output terminals are short-circuited to power supply at the same time. If short-circuit to power supply occurs on both the plus and minus side output terminals at the same time with a short-circuit resistor which does not actuate the protection circuit, the power GND terminal current may exceed 10 A and the wire melts down since the current exceeds the capacity of Au wire.
• V CC - GND reverse connection Parasitic device is created everywhere and the circuit destruction takes place. 4. Countermeasure for shock noise of the AN7198Z Points of shock noise prevention Plus and minus output of the BTL amp. is not changed suddenly by STB-on/off and Mute-on/off. 1) Standby pin to off (pin 5 VSTB = 5 V fi 0 V) (Standby state fi Operating state) (1) Ripple filter pin (pin 12) becomes on gradually (Charge up to VCC ) when VSTB = 0 V fi 5V. Current source and reference voltage are on instantaneously. (2) Output D range suppression circuit is incorporated which limits the dynamic range of output to 0 V < VOUT < VRF - 3 VBE when the ripple filter pin voltage is less than 6.8 V. DC voltage change of input circuit causes steep DC voltage change of output pin and that generates shock noise. This steep DC voltage change can be suppressed by the above mentioned circuit. Voltage of the mute pin (pin 7) makes high forcedly in the inside circuit. (3) Input mute is on when the ripple filter pin voltage V RF is less than 6.8 V. This prevents the shock noise which is inputted from the pre-stage of power amp. Also, mute is on in order to prevent the abnormal sound which is generated by clipping of waveform. (Output is clipped due to narrow D range at start up) (4) DC voltage of output pin changes with 1/2 voltage of the ripple filter pin. Steep changes of output pin voltage is suppressed by start up gradually of the ripple filter pin. (5) Output waveform of each plus and minus output at power supply on changes as same by symmetric placement of inverting and non-inverting amplifier which consist of BTL amp. Image figure of output waveform, RF-pin waveform has exponential characteristics in actually. V STB -on 3 VBE Clamp-off Mute-offReference voltage constant current source Mute-on t V OUT V OUT without D-range suppression circuit Output D-range on RF

ICs for Audio Common Use AN7198Z n Technical Information (continued) 4. Countermeasure for shock noise of the AN7198Z (continued) 2) Standby pin to off (pin 5 VSTB = 5 V fi 0 V) (Operating state fi Standby state) (1) Ripple filter pin (pin 12) becomes off gradually (Discharge down to 0 V) when VSTB = 5 V fi 0 V. Current source and reference voltage are on until VRF < 2 VBE . (2) Output D range suppression circuit operates when the ripple filter pin voltage is less than 6.8 V. The circuit limits to 0 V < VOUT < VRF - 3 VBE . DC voltage change of input circuit causes steep DC voltage change of output pin and that generates shock noise same as at standby pin is on. This steep DC voltage change can be suppressed by the above mentioned circuit. Voltage of the mute pin (pin 7) makes high forcedly in the inside circuit. (3) Input mute is on when ripple filter pin voltage V RF is less than 6.8 V. This prevents the shock noise which is inputted from the pre-stage of power amp. Also, mute is on in order to prevent the abnormal sound which is generated by clipping of waveform. (The purpose is same as the countermeasure of start up period.) (4) DC voltage of output pin changes with 1/2 voltage of the ripple filter pin. Steep changes of output pin voltage is suppressed by start up gradually of the ripple filter pin. (5) Output waveform of each plus and minus output at power supply on changes as same by symmetric placement of inverting and non-inverting amplifier which consist of BTL amp. Image figure of output waveform, RF-pin waveform has exponential characteristics in actually. 3) Muting on/off (Pin7 low: Muting state, high: Operating state) (1) AC mute circuit which mute the AC component only by the simple attenuator circuit is adopted. Conventional system generates shock noise due to change steeply of output DC voltage by cutting of input DC voltage and muting of AC component. V STB -off

3 VBE Clamp-off

V OUT V OUT without D-range suppression circuit Output D-range off RF 6 15 kW600 WAtt. 0 dB 15 kW600 W 22 kW V REF = VCC 30 kW 10 kW 1.0 mF Mute 5 V

0 V IO

AN7198Z ICs for Audio Common Use n Technical Information (continued) 4. Countermeasure for shock noise of the AN7198Z (continued) 3) Muting on/off (Pin7 low: Muting state, high: Operating state) (continued) (2) Attack and recovery time of muting on/off is determined by the external CR time constant of pin 7. (3) There is afraid of shock noise when time constant is set to 10 ms or less. (Since output DC voltage is changed approx. 50 mV by muting on/off.) Less than– 50 mV Approx. 6.3 V Output DC Mute pin voltage Output AC 5 V 0 V n Application Circuit Example Beep In GND(Sub) GND(Input) ch.1 In ch.2 In Ripple Filter Standby Mute ch.1 GND ch.2 GND 2200 mF 33 mF ch.1 Out (-) ch.1 Out (+) ch.2 Out (-) 10 kW 10 kW 20 kW 1 mF ch.2 Out (+) V CC 5 V 0 V 5 V 0 V Ref. Protection Cct. Att.Con. Att Att Att Att Figure 13