ICs for Audio Common Use AN7191NZ Dual 20 W BTL audio power amplifier ■ Overview 4.00±0.20 1.50±0.10 2.40±0.50 1 15 1.27 0.50+0.20 –0.10 • BTL 20 W × 2-channel (4 Ω), GV = 34 dB • Built-in various protection circuits (thermal protection, short circuit to VCC and short circuit to GND, VCC-open short circuit to VCC , GND-open short circuit to GND, overvoltage and supply surge, and ASO, etc.) Especially, the supply surge breakdown voltage is 100 V or more. GND open breakdown voltage is 16 V or more. • Built-in standby function (free from shock noise at standby 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 are 50 ms or less. • Reduction in external components It eliminates the need for NF and BS electrolytic capacitors. Muting function is not required, and power supply choke coil is unnecessary. • Provided with beep sound input pin • 2 Ω load guaranteed 13.25±0.30 15.65±0.50 18.95±0.50 φ3.60±0.10 (0.61) (1.80) (2.54) ■ Features 3.25±0.10 Unit : mm 18.00±0.30 13.50±0.30 10.0±0.30 The AN7191NZ is an audio power IC developed for the sound output of car audio (dual 20 W). It is incorporating various protective circuits to protect the IC from destruction by GND-open short circuit to GND and power supply surge which are the important subject of power IC protection, so the IC will largely contribute to a high reliability design of equipment. Also, it is incorporating a perfect muting circuit which is free from shock noise, so that a shock noise design under the set transient condition can be made easily using together with its standby function. R0.55 (1.95) 0.25+0.15 –0.05 19.00±0.30 19.30±0.30 HZIP015-P-0745A ■ Applications • Car audio 1 AN7191NZ ICs for Audio Common Use 1 12 VCC Ripple filter ■ Block Diagram 4 13 Protection cct. Att. 15 2 Att.con. Ch.2 out (−) Ch.2 out (+) Att. 9 11 GND (input) 5 Standby Ch.1 in 6 10 Beep in GND (sub) 8 Att. Ch.2 GND Att. Ch.2 in Ch.1 out (+) 14 Ref. 7 Ch.1 out (−) 3 Mute Ch.1 GND ■ Pin Descriptions Pin No. Description Pin No. Description 1 Power supply 9 Grounding (input) 2 Ch.1 output (+) 10 Beep sound input 3 Grounding (output ch.1) 11 Ch.2 input 4 Ch.1 output (−) 12 Ripple filter 5 Standby 13 Ch.2 output (−) 6 Ch.1 input 14 Grounding (output ch.2) 7 Muting 15 Ch.2 output (+) 8 Grounding (sub) ■ Absolute Maximum Ratings Parameter Supply voltage *2 Peak supply voltage *3 Supply current Power dissipation *4 Operating ambient temperature Storage temperature Note) *1 : *2 : *3 : *4 : 2 *1 *1 Symbol Rating Unit VCC 25 V Vsurge 80 V ICC 9.0 A PD 59 W Topr −30 to +85 °C Tstg −55 to +150 °C Ta = 25°C except power dissipation, operating ambient temperature and storage temperature. Without signal Time = 0.2 s Ta = 85°C ICs for Audio Common Use AN7191NZ ■ Recommended Operating Range Parameter Symbol Range Unit VCC 8.0 to 18.0 V Supply voltage ■ Electrical Characteristics at VCC = 13.2 V, freq. = 1 kHz, Ta = 25°C Parameter Symbol Quiescent current Standby current Output noise voltage *1 Voltage gain 1 Conditions Min Typ Max Unit ICQ VIN = 0 mV, RL = 4 Ω 120 250 mA ISTB VIN = 0 mV, RL = 4 Ω 1 10 µA VNO Rg = 4.7 kΩ, RL = 4 Ω 0.22 0.5 mV[rms] GV1 VIN = 40 mV, RL = 4 Ω 32 34 36 dB Total harmonic distortion 1 THD1 Po = 0.5 W, RL = 4 Ω 0.07 0.4 % Maximum output power 1 PO1 THD = 10%, RL = 4 Ω 16 18 W RR RL = 4 Ω, Rg = 4.7 kΩ, Vr = 1 V[rms], fr = 1 kHz 60 72 dB CB VIN = 40 mV, RL = 4 Ω 0 1 dB CT VIN = 40 mV, RL = 4 Ω, Rg = 4.7 kΩ 55 65 dB Ripple rejection ratio *1 Channel balance Cross-talk *1 Output offset voltage Muting effect *1 Input impedance Voltage gain 2 VOFF Rg = 4.7 kΩ, RL = 4 Ω − 250 0 250 mV MT VIN = 40 mV, RL = 4 Ω 70 82 dB VIN = ± 0.3 VDC 22 28 35 kΩ VIN = 40 mV, RL = 2 Ω 32 34 36 dB Zi GV2 Total harmonic distortion 2 THD2 Po = 0.5 W, RL = 2 Ω 0.1 0.5 % Maximum output power 2 16 24 W − 100 0 100 mV[p-0] 0.10 0.5 % PO2 THD = 10%, RL = 2 Ω *2 VS RL = 4 Ω, Rg = 4.7 kΩ, VMUTE = 5 V, VSTB = on/off, 50Hz HPF-on Total harmonics distortion 3 THD3 Shock noise VIN = 10 mV, fIN = 20 kHz, Rg = 4.7 kΩ, 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 voltages of 0 V and 5 V at the time shown in the right. Standby terminal voltage 5V 0V 120 ms 120 ms 3 AN7191NZ ICs for Audio Common Use ■ Terminal Equivalent Circuits Pin No. Equivalent circuit 1 2 1 Description Pre-amp. Drive circuit DC voltage Power supply connection pin 13.2 V Ch.1 output pin (+) : Ch.1 positive-phase output pin. 6.6 V GND (Output) : Grounding pin for ch.1 output. 0V Ch.1 output pin (−) : Ch.1 reverse-phase output pin. 6.6 V 2 Drive circuit 3 30 kΩ 1.2 kΩ 3 4 VREF = 6.6 V 1 Drive circuit Pre-amp. 4 Drive circuit 3 5 30 kΩ VREF = 6.6 V 1.2 kΩ 5 10 kΩ Standby control pin : Standby changeover pin threshold voltage approx. 2.1 V. Ch.1 input pin : Ch.1 input signal applied pin input impedance 30 kΩ. 0 mV to 10 mV Mute control pin : Mute changeover pin threshold voltage approx. 2.0 V. 900 Ω 6 6 Approx. Approx. 15 µA 15 µA 200 Ω 400 Ω 30 kΩ 7 7 5 kΩ 4 ICs for Audio Common Use AN7191NZ ■ Terminal Equivalent Circuits (continued) Pin No. Equivalent circuit 8 GND (sub) : Being connected to substrate only. 0V 9 GND (input) : Ground pin for input. 0V 10 1.2 kΩ VREF = 2.1 V Description 30 kΩ 1.2 kΩ 2 DC voltage Beep sound input pin : Beep sound signal input pin. Input impedance 10 kΩ. 2.1 V Ch.2 input pin : Ch.2 input signal applied pin. Input impedance 30 kΩ. 1 mV to 10 mV 20 kΩ 20 kΩ 10 1.2 kΩ VREF = 2.1 V 11 15 1.2 kΩ 30 kΩ 11 Approx. Approx. 15 µA 15 µA 200 Ω 400 Ω 30 kΩ VCC 12 Ripple filter pin : Output current 3 mA to 10 mA. 13.0 V Ch.2 output pin (−) : Ch.2 reverse-phase output pin. 6.6 V 30 kΩ 12 1.2 mA 40 kΩ 200 µA 13 1 Drive circuit Pre-amp. 13 Drive circuit 15 14 30 kΩ VREF = 6.6 V 1.2 kΩ GND (output) : Ground pin for ch.2 output. 0V 5 AN7191NZ ICs for Audio Common Use ■ Terminal Equivalent Circuits (continued) Pin No. 15 Equivalent circuit 1 Description Ch.2 output pin (+) : Ch.2 positive-phase output pin. Pre-amp. Drive circuit DC voltage 6.6 V 14 VREF = 6.6 V Drive circuit 15 30 kΩ 1.2 kΩ ■ Usage Notes 1. Always attach an outside heat sink when using the chip. Note that, 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. 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 Ω. 7. When the beep sound function is not used, open the beep sound input pin (pin 10) or connect it to pin 9 with around 0.01 µF 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 improve. ■ Technical Information • PD Ta curves of HZIP015-P-0745A P D Ta 120 Rth (j−c) = 1.1°C/W Pth (j−a) = 68.3°C/W Infinit heat sink 113.6 Power dissipation PD (W) 100 80 1°C/W heat sink 60 59.5 2°C/W heat sink 40.3 40 3°C/W heat sink 30.5 5°C/W heat sink 20.5 20 10°C/W heat sink 11.3 Without heat sink 1.8 0 0 25 50 75 100 Ambient temperature Ta (°C) 6 125 150 ICs for Audio Common Use AN7191NZ ■ Technical Information (continued) [1] Main characteristics PC , ICC PO Consumption power PC (W) 35 30 Output voltage PO (W) 45 10 VCC = 13.2 V RL = 4 Ω freq. = 1 kHz 9 40 8 35 7 30 6 50 RL = 4 Ω freq. = 1 kHz THD = 10% 25 20 15 10 25 5 ICC 4 20 3 15 PC 10 2 5 5 1 0 0 0 10 5 15 20 25 0 5 10 15 20 25 0 30 Output voltage PO (W) Supply voltage VCC (V) PO , THD VIN (RL = 4 Ω) PO , THD VIN (RL = 2 Ω) 100 10 50 5 50 5 20 2 10 1 0.5 THD 10 kHz 2 0.2 PO 1 0.1 THD 100 Hz 1 kHz 0.5 VCC = 13.2 V RL = 4 Ω freq. = 1 kHz 400 Hz HPF 30 kHz LPF 0.2 0.1 1 0.02 2 10 1 5 0.5 2 0.2 THD 100 Hz 1 kHz 1 0.1 PO 0.5 VCC = 13.2 V RL = 2 Ω freq. = 1 kHz 400 Hz HPF 30 kHz LPF 0.2 0.01 1 000 100 10 0.05 THD 10 kHz 20 Output power PO (W) 5 Total harmonic distortion THD (%) 10 Output power PO (W) 100 0.1 1 10 0.05 Total harmonic distortion THD (%) 40 Supply current ICC (A) PO VCC 0.02 0.01 1 000 100 Input voltage VIN (mV) Input voltage VIN (mV) GV , PO freq. THD freq. 10 25 Voltage gain GV (dB) GV −1 20 −2 PO −3 15 VCC = 13.2 V RL = 4 Ω PO = 1 W THD = 10 % −4 10 100 1k 10k Frequency freq. (Hz) 10 100k Total harmonic distortion THD (%) 34 dB Maximum output power PO (W) 0 5 2 1 0.5 0.2 0.1 0.05 VCC = 13.2 V RL = 2 Ω, 4 Ω PO = 1 W 0.02 0.01 10 100 1k 10k 100k Frequency freq. (Hz) 7 AN7191NZ ICs for Audio Common Use ■ Technical Information (continued) [1] Main characteristics (continued) GV VCC V THD VCC CC CC 10 VCC = 13.2 V RL = 4 Ω freq. = 1 kHz VIN = 20 mV 400 Hz HPF 30 kHz LPF Total harmonic distortion THD (%) 5 0 Voltage gain GV (dB) 34 dB −1 −2 −3 VCC = 13.2 V RL = 4 Ω freq. = 1 kHz 400 Hz HPF 30 kHz LPF −4 0 5 10 15 20 2 1 0.5 0.2 0.1 0.05 0.02 0.01 0 25 5 10 VNO Rg 1.0 Wide band 0.5 DIN audio 0 1k 10k RL = 4 Ω VIN = 0 mV Rg = 4.7 kΩ 2.0 Output end noise voltage VNO (mV) Output end noise voltage VNO (mV) 1.5 100 1.5 1.0 Wide band 0.5 DIN audio 0 100k 0 Input impedance Rg (Ω) 5 10 70 70 60 50 40 30 VCC = 13.2 V RL = 4 Ω VIN = 0 mV Rg = 0 Ω fr = 120 Hz DIN audio filter 1 10 100 1 000 10 000 Power supply ripple voltage Vr (mV[rms]) 8 Ripple rejection ratio RR (dB) Ripple rejection ratio RR (dB) 80 0 20 25 RR fr 80 10 15 Supply voltage VCC (V) RR Vr 20 25 VNO VCC g VCC = 13.2 V RL = 4 Ω VIN = 0 mV 10 20 Supply voltage VCC (V) Supply voltage VCC (V) 2.0 15 60 50 40 30 VCC = 13.2 V RL = 4 Ω VIN = 0 mV Rg = 0 Ω Vr = 1 V[rms] DIN audio filter 20 10 0 10 100 1k Power supply ripple frequency fr (Hz) 10k ICs for Audio Common Use AN7191NZ ■ Technical Information (continued) [1] Main characteristics (continued) CT VIN 80 80 70 70 60 60 Cross-talk CT (dB) Ripple rejection ratio RR (dB) RR VCC 50 40 30 RL = 4 Ω VIN = 0 mV Rg = 0 Ω fr = 120 Hz Vr = 1 V[rms] DIN audio filter 20 10 0 0 50 40 30 20 VCC = 13.2 V RL = 4 Ω freq. = 1 kHz Rg = 4.7 kΩ DIN audio filter 100 1 000 10 5 10 15 20 0 25 1 10 Supply voltage VCC (V) Input voltage VIN (mV) CT freq. CT VCC 80 80 70 70 60 60 ch.2 → ch.1 Cross-talk CT (dB) Cross-talk CT (dB) ch.2 → ch.1 50 40 30 20 0 10 100 1k 30 RL = 4 Ω VIN = 20 mV Rg = 4.7 kΩ fr = 1 kHz DIN audio filter 10 0 10k 0 5 10 15 Frequency freq. (Hz) Supply voltage VCC (V) ICQ VCC ISTB VCC 200 Quiescent circuit current ICQ (mA) 40 20 VCC = 13.2 V RL = 4 Ω Rg = 4.7 kΩ DIN audio Filter 10 50 20 VIN = 0 mV Rg = 0 Ω RL = 4 Ω 150 20 25 VIN = 0 mV Rg = 0 Ω RL = 4 Ω Standby current ISTB (µA) 15 100 50 10 5 ISTB 0 0 5 10 15 Supply voltage VCC (V) 20 25 0 0 5 10 15 20 25 Supply voltage VCC (V) 9 AN7191NZ ICs for Audio Common Use ■ Technical Information (continued) [1] Main characteristics (continued) ICQ VSTB VCC = 13.2 V VIN = 0 mV Rg = 0 Ω RL = 4 Ω VIN = 0 mV Rg = 0 Ω RL = 4 Ω 100 Output offset voltage VOFFSET (mV) Quiescent circuit current ICQ (mA) 200 VOFFSET VCC 150 100 200 100 0 − 100 50 − 200 − 300 0 0 1 2 3 4 0 5 5 Standby terminal voltage VSTB (V) 10 100 90 90 80 80 70 60 VCC = 13.2 V RL = 4 Ω Rg = 4.7 kΩ freq. = 1 kHz DIN audio filter 1 100 10 1k Muting effect ME (dB) Muting effect ME (dB) 100 30 70 60 50 40 VCC = 13.2 V RL = 4 Ω Rg = 4.7 kΩ PO = 1 W DIN audio filter 30 20 10k 10 ME VMUTE 100 70 60 50 RL = 4 Ω Rg = 4.7 kΩ freq. = 1 kHz PO = 1 W DIN audio filter 30 20 5 10 15 20 Supply voltage VCC (V) 25 Muting effect ME (dB) 80 100k RL = 4 Ω Rg = 4.7 kΩ freq. = 1 kHz PO = 1 W DIN audio filter 90 80 Muting effect ME (dB) 10k ME VCC 90 10 1k Frequency freq. (Hz) 100 0 100 Input voltage VIN (mV[rms]) 40 25 ME freq. 110 40 20 Supply voltage VCC (V) ME VIN 50 15 70 A B 60 50 40 30 20 A 4.7 kΩ 7 B 10 µF 10 0 0 1 2 3 4 Mute terminal voltage VMUTE (V) 5 ICs for Audio Common Use AN7191NZ ■ Technical Information (continued) [2] Application note 1. Standby function Terminal state Terminal voltage Power 1) The power can be turned on or off by making pin 5 (standby terminal) high or low. Open 0V Standby state 2) The standby terminal has threshold voltage of Low 0 V to 1.0 V Standby state approx. 2.1 V, however, it has temperature deHigh Higher than 3 V Operating state pendency of approx. − 6 mV/°C. The recommended range of use is shown in table 1. Table 1 3) The internal circuit of standby terminal 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. 5V VSTB 10 kΩ 5 Protection circuit RF Constant current source 0V Sub ISTB = VSTB−2.7 V [mA] 10 kΩ 3.5 kΩ 3.5 kΩ 3.5 kΩ 3.5 kΩ Figure 1 4) A power supply with no ripple component should be used for the control voltage of standby terminal. 2. Oscillation countermeasures 1) In order to increase the oscillation allowance, connect a capacitor and a resistor in series between each output terminal and GND as shown in figure 2. 2) The use of polyester film capacitor having a little fluctuation with temperature and frequency is recommended as the 0.22 µF capacitor for oscillation prevention. 1 2,4 13,15 To speaker 0.22 µF 2.2 Ω 3,14 Figure 2 11 AN7191NZ ICs for Audio Common Use ■ Technical Information (continued) [2] Application note (continued) 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 µF) for DC component cut in series with the input terminal. Check the low-pass frequency characteristics to determine the capacitance value. 2) 10 kΩ or less of signal source impedance Rg can reduce the output noise voltage. 3) The output offset voltage fluctuates when the signal source impedance Rg is changed. A care must be taken when using the circuit by directly connecting the volume 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 µF between the input terminal and input GND. When a high frequency signal is inputted, malfunction of protective circuits may occur. 15 µA 1 µF Input signal 0.01 µF 6 11 4.7 kΩ 200 Ω 15 µA To power 400 Ω Attenuator 30 kΩ Figure 3 4. Ripple filter 1) In order to suppress the fluctuation of supply voltage, connect a capacitor of approx. 33 µF between RF terminal (pin 12) and GND. 2) Relation between RR (ripple rejection ratio) and a capacitor The larger the capacitance of a ripple filter is, the better the ripple rejection becomes. 3) Relation between the rise time of circuit and a capacitor The larger the capacitance of a ripple filter is, the longer the time from the power-on (standby : high) to the sound release becomes. 4) The DC voltage of output terminal is approximately the middle point of the ripple filter terminal voltage. 5) The internal circuit of ripple filter terminal is as shown in figure 4 and the charge current is approx. 3 mA to 10 mA. 12 ICs for Audio Common Use AN7191NZ ■ Technical Information (continued) [2] Application note (continued) 4. Ripple filter (continued) VCC 30 kΩ Constant current source Protection circuit 12 33 µF 200 µA 20 kΩ 1.2 mA VREF 20 kΩ 3.5 kΩ 3.5 kΩ Figure 4 6) After power off (STB-low), it takes about 10 seconds or less for the total circuit current to become the standby current (10 µA or less). In order to reduce the inspection time at the set, insert the resistor of approx. 47 kΩ between the ripple filter terminal and GND. This can shorten the time to reach the standby current. 5. GND terminal _ _ g 1) Be sure to short-circuit each GND terminal of pin 3, pin 8, pin 9 and pin 14 at the outside 1 3 8 9 14 of the IC when use. 2) For each GND terminal, the onepoint earth, referenced to the GND connection point of electrolytic capacitor between the To GND of input supply terminal and GND, is Figure 5 most effective for reducing the distortion. Even in the worst case, ground pin 8, pin 9 of input GND separately from all the other GND terminals. 3) Each GND terminal is not electrically short-circuited inside. Only pin 8 is connected with the substrate. 4) Pin 9 is input signal GND. Connect only pin 9 with Pre-GND. 6. Cooling fin 1) The radiation 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 not necessary to connect with GND in use, but connect with the power GND when connect with GND.) 13 AN7191NZ ICs for Audio Common Use ■ Technical Information (continued) [2] Application note (continued) 7. Shock noise 1) STB on/off No shock noise is released. 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 µF 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 low. 2) The muting circuit is as shown in figure 6. The amplifier gain including attenuator block is given in the following equation : GV = I1 × 50 I2 Original gain From the above equation, the amplifier gain can be made as 0 time by setting I1 at 0 mA in muting. 3) The threshold voltage of VMUTE is as follows : Mute-off : Approx. 1 V or less g Mute-on : Approx. 3 V or less I1 Mute/On 5V Input 4.7 kΩ VMUTE 0V Mute/Off I2 10 µF Output stage 7 I1 I2 5 kΩ Output stage Attenuator block I1 = approx. 120 µA I2 = approx. 120 µA Figure 6 4) Attack time and recovery time can be changed by the external CR of pin 7. For recommended circuits (figure 7. 4.7kΩ, 10 µF), 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), (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 and can not be changed by the addition of an external resistor. 14 ICs for Audio Common Use AN7191NZ ■ Technical Information (continued) [2] Application note (continued) 10. Beep sound input function 1) The application circuit using the beep sound input is shown in figure 7. Connect the beep signals from the microcomputer to pin 10 via the capacitor C1 for DC cut and the resister R1 for voltage gain adjustment. 2) The voltage gain of beep sound terminal is approx. 3.4 dB. With settings shown in the following drawing, it is approx.−12.7 dB (f = 1 kHz). 3) The beep sound is outputted to output terminals pin 2 and pin 15 only. 1.2 kΩ VREF = 2.1 V 28 dB 2 Beep input C1 47 kΩ 10 20 kΩ 20 kΩ 0.022 µF R1 600 GV = × 25 20 k + 1 200 1/jωC1 + R1 + 2 15 1.2 kΩ VREF = 2.1 V 28 dB Figure 7 11. Two IC use Figure 8 shows the application circuit example when two ICs are used : Out(RR) 4.7 kΩ Power supply 15 13 11 9 7 5 3 1 2 200 µF Standby 0.22 µF 0.22 µF 2.2 Ω 14 12 10 8 6 2 Mute 4 2.2 kΩ Out(FR) 22 µF 0.22 µF 0.22 µF 47 µF 4.7 kΩ S-GND 15 1 µF 13 9 1 µF 11 1 µF 7 In(FL) 2.2 Ω Out(RL) 5 In(RL) 2.2 Ω 1 µF 3 In(FR) 1 In(RR) 2.2 Ω 0.22 µF 0.22 µF 14 12 10 8 6 4 0.022 µF 2 2.2 Ω 2.2 Ω Out(FL) In(FL) 47 kΩ 0.22 µF 0.22 µF 4.7 kΩ 2.2 Ω 2.2 Ω Figure 8 15 AN7191NZ ICs for Audio Common Use ■ Technical Information (continued) [2] Application note (continued) 11. Two IC use (continued) 1) Supply terminal Short-circuiting each other, insert an electrolytic capacitor of approx. 2 200 µF into the supply terminals. However, if sufficient characteristics of the ripple rejection can not be obtained, use an even larger capacitor or insert a 2 200 µF capacitor into each IC. The best sound quality can be obtained by inserting a 2 200 µF capacitor near the terminal of each IC. 2) Standby terminal (pin 5) The connection of standby terminals with each other does not result in an abnormal operation. Connect with the microcomputer after connecting the standby pins with each other. At that time, the current flowing into the standby terminal is twice larger the current which is described in 1. Standby function. 3) Muting terminal (pin 7) It does not result in the abnormal operation even if the muting terminals are short-circuited with each other. The muting time constant changes when two ICs connection is made. If the CR constants are set at twice and 1/2 time respectively, the time constant value becomes as same as the value when 1 IC is used. 4) Beep sound input terminal (pin 10) Short-circuit between the beep sound input terminals 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 kΩ). 5) Ripple filter terminal (pin 12) Short-circuit between ripple filter terminals does not result in an abnormal operation. However, if the standby of each IC is individually controlled, the short-circuiting is not allowed. Use the circuit after connecting a capacitor (33 µF) to each IC. 1 VCC 12 Ripple filter ■ Application Circuit Example 16 Muting Ch.1 in 9 Ch.2 in 11 15 Ch.2 out (+) 7 Ch.1 out (+) 2 Standby 5 13 Ch.2 out (−) 6 Ch.1 out (−) 4 Beep in 10 14 Ch.2 GND 8 Ch.1 GND 3