ICs for Audio Common Use AN5274 4.0 W × 2 (18 V, 8 Ω) Power Amplifier with Mute Function and Volume Control Unit : mm ■ Overview 12 7.7±0.3 (10.0) R1.8 21.9±0.3 29.6±0.3 3.5±0.3 1.45±0.15 1 (1.2) 19.1±0.3 1.80±0.15 1.2±0.1 (12.5) +0.10 0.25 –0.05 2.54 0.6 • Built-in DC volume control • Built-in mute circuit • Built-in thermal protection circuit • Built-in over current protection circuit • Higher ripple rejection as compared to AN5273 • VCC operating range : 14.2 V to 27.5 V +0.15 ■ Features 0.6 –0.05 (1.27) 20.0±0.3 (1.27) φ3.6 (10.0) 29.75±0.30 28.0±0.3 (1.3) The AN5274 is a monolithic integrated circuit designed for 4.0 W (18 V, 8 Ω) output audio power amplifier. It is a dual channel SEPP IC suitable for stereo operation in TV application. HSIP012-P-0000A ■ Applications • TV ■ Block Diagram Volume 12 Out1 11 NF1 10 VCC GND 8 NF2 7 Out2 6 RF 5 In2 4 RR 3 Vol. 2 In1 Mute 1 Ripple filter 9 Over current thermal protection circuit ■ Pin Descriptions Pin No. Description Pin No. Description 1 Mute control 7 Ch.2 output 2 Ch.1 input 8 Negative feedback ch.2 3 Volume control 9 GND 4 Ripple rejection 10 VCC 5 Ch.2 input 11 Negative feedback ch.1 6 Ripple filter 12 Ch.1 output 1 AN5274 ICs for Audio Common Use ■ Absolute Maximum Ratings Parameter Symbol Rating Unit VCC 29 V ICC 3.5 A PD 37.5 W Topr −25 to +75 °C Tstg −55 to +150 °C Supply voltage Supply current Power dissipation *2 Operating ambient temperature Storage temperature *1 *1 Note) *1 : Ta = 25 °C except power dissipation, operating ambient temperature and storage temperature. *2 : Power dissipation of the package at Ta = 75 °C. ■ Recommended Operating Range Parameter Supply voltage Symbol Range Unit VCC 14.2 to 27.5 V ■ Electrical Characteristics at VCC = 18 V, f = 1 kHz, RL = 8 Ω, Ta = 25 °C Parameter Symbol Quiescent current Voltage gain *1 Total harmonic distortion Maximum power output *1 Channel balance Max. volume attenuation Mute attenuation *1 *1 Output noise voltage *1 Ripple rejection *1 Conditions Min Typ Max Unit ICQ No input signal 17 25 33 mA GV VIN = 90 mV 28 30 32 dB THD VIN = 90 mV 0.3 1.0 % POmax THD = 10 % 3.6 4.1 W CB VIN = 90 mV −1 0 1 dB Att VIN = 90 mV −70 −64 dB MAtt VIN = 90 mV −70 −64 dB VNO Rg = 10 kΩ, Din-Audio Filter 0.6 1.0 mV[rms] RR VR = 280 mV[rms], fR = 100 Hz Rg = 10 kΩ 30 35 dB Note) *1 : With a filter band from 20 Hz to 20 kHz used. • Design reference data Note) The characteristic values below are theoretical values for designing and not guaranteed. Parameter Channel cross-talk Symbol Conditions Min Typ Max Unit CT VOUT = 1 V[rms], Volume = max. 47 57 dB Max. power dissipation PDmax1 Use 10 °C/W heat sink 5 7 W Max. power dissipation PDmax2 VCC = 15.6 V, RL = 16 Ω No heat sink 1.9 W Input dynamic range *2 DRIN THD = 1 %, PO = 1 W 6.1 7.2 V[p-p] Note) *2 : In order to measure input dynamic range correctly, it is necessary to reduce the gain by decreasing the DC volume to 1 V to 2 V. 2 ICs for Audio Common Use AN5274 ■ Application Circuit Example 22 kΩ 33 µF 1 µF Audio mute 5V 20 kΩ 20 kΩ 1000 µF 10 kΩ RL = 8 Ω Out1 12 NF1 11 VCC 10 GND 9 1 µF 100 µF NF2 8 Out2 7 3.3 µF RF 6 In2 5 RR 4 Vol. 3 In1 2 Mute 1 AN5274 0.047 µF 10 µF 20 Ω 1 kΩ 5V 10 µF 1000 µF 1 kΩ 0.047 µF 20 Ω 1000 µF RL = 8 Ω 18 V ■ Usage Notes 1) Depending on the maximum application output power, external heatsink may be needed. External heatsink should be fixed to the chassis. 2) Fin of the IC can be connected to GND. 3) Please prevent output to VCC short and output to GND short. 4) The temperature protection circuit will operate at Tj around 150 °C. However, if the temperature decreases, the protection circuit would automatically be deactivated and resume normal operation. ■ Technical Information • HSIP012-P-0000A Package power dissipation PD T a 70.0 Rth (j−c) = 2 °C/W Rth (j−a) = 42 °C/W Infinite heat sink Power dissipation PD (W) 62.5 60.0 50.0 41.7 1 °C/W heat sink 40.0 31.3 2 °C/W heat sink 30.0 3 °C/W heat sink 25.0 20.0 17.9 5 °C/W heat sink 10.4 10 °C/W heat sink 10.0 Without heat sink 3.0 0.0 0 25 50 75 100 125 150 Ambient temperature Ta (°C) 3 AN5274 ICs for Audio Common Use ■ Technical Information (continued) • Application Note 1) Voltage gain The voltage gain of the AN5274 can be varied by changing the resistor R2 as shown below : GV input= 4 dB which is fixed in internal circuit. R1 is always fixed at 20 kΩ. R2 is variable. Pin7,12 GVI GVO = 20 log (R1/R2) Pin8 11 Typical values are : R1 = 20 kΩ, R2 = 1 kΩ R1 GVO = 20 log (20 k/1 k) = 26 dB CNF = 10 µF R2 GVTOTAL = GVI + GVO = 4 dB + 26 dB = 30 dB 2) DC volume control The DC volume control range is 0 V to 5 V. This range is used in order to be easily controlled by micro-computer using PWM output. The recommended circuit and volume attenuation characteristic are shown below : AN5274 Volume attenuation 5V Microcomputer IC 300 Ω 3 Volume control R4 18 kΩ R5 12 kΩ PWM output C4 2.2 µF 0 5 (V) Volume at Pin3 Fig. Volume characteristic of AN5274 Fig. Volume control interface circuit for AN5274 0.6 3) Mute control Mute is ON when 5 V is applied to Pin1. Then Q1 would turn ON and able to drive other part of the circuits. The external RC components provide a time constant for switching ON and OFF. Mute ON 5 V 0V OFF R 22 kΩ ZMUTE C 33 µF 1 Q1 The purpose of the Mute is to attenuate the AC signal before it goes to the output. 20 kΩ 0V 1.8 V 2.1 V 5V Threshold voltage at Pin1 : Mute OFF 4 Mute ON ICs for Audio Common Use AN5274 ■ Technical Information (continued) • Application Note (continued) 4) Oscillation To prevent oscillation, it is advisable to use RC (Zobel network) at output. C of polyester film capacitor has smaller characteristic fluctuation with temperature and frequency. The resistor R connected in series with C is effective for phase correction at high frequency, and as a result, it improves the oscillation allowance. 1000 µF Pin7 12 C 0.047 µF R 20 Ω RL = 8 Ω 5) Power-ON/OFF pop-noise elimination The output pins 7, 12 and VO, during power turns ON and OFF are shown below : VO Pin7 & Pin12 33 µF CRF VCC 10 RF 6 VCC CVCC 47 µF CRF = 100 µF Turn ON time Turn OFF time The turn ON time in the AN5274 is determined by the capacitance value of CRF. If value of the CRF is smaller, VO will turn on faster. The turn OFF time is dependent on the capacitance value of CVCC. Pop-noise would occur when VCC voltage declines faster than RF voltage. To solve this, increase the discharge time of VCC by increasing the capacitance values of CVCC. The recommended values of capacitance for CVCC and CRF are shown below : CRF CVCC Recommended Operating VCC Range Unit 33 µF 470 µF 14.5 to 27.5 V 5 AN5274 ICs for Audio Common Use ■ Technical Information (continued) • Application Note (continued) 6) Standby circuit Standby function can be implemented in the AN5274 by external solution. It is realised by pulling the RF voltage to low and output voltage would follow RF as shown in the diagram. DC voltage 5V RF 6 1/2VCC Stand-by 0V ON (Pin7 & Pin12) VO (DC) 100 µF 5V 5V Stand-by Time OFF 7) Ripple rejection improvement RR 4 The ripple rejection of the AN5274 can be improved by another 15 dB by connecting a capacitor to Pin4. CRR 6 Recommended capacitor CRR = 1.0 µF to 4.7 µF ICs for Audio Common Use AN5274 ■ Technical Information (continued) • Characteristic Curve Chart PO, THD VIN 100 1 10 THD 0.1 1 0.01 1 6 RL = 16 Ω 4 0 10 0.1 1000 100 RL = 8 Ω 2 12 14 16 18 20 22 24 Input voltage VIN (mV) Supply voltage VCC (V) DC volume characteristics GV, THD f VCC = 18 V RL = 8 Ω VIN = 90 mV f = 1 kHz 0 30 26 28 GV 28 −10 Voltage gain GV (dB) Volume attenuation (dB) 10 8 −20 −30 −40 −50 26 24 22 VCC = 18 V RL = 8 Ω VIN = 90 mV Vol. = max. 1.0 0.8 0.6 THD −60 0.4 Total harmonic distortion THD (%) PO f = 1 kHz THD = 10 % Vol. = max. Output power PO (W) VCC = 18 V RL = 8 Ω f = 1 kHz Vol. = max. Total harmonic distortion THD (%) Output power PO (W) 10 PO VCC 10 0.2 −70 0 1 2 3 4 5 DC volume (V) 10 100 1k 10k 0 100k Frequency f (Hz) RR f Ripple rejection (dB) 50 40 RR 30 VCC = 18 V RL = 8 Ω VR = 280 mV Vol. = max. 20 10 100 1k 10k 100k Frequency f (Hz) 7