ICs for Audio Common Use AN5272 4.0 W × 2 (18 V, 8 Ω) Power Amplifier with Variable Audio Output and Volume Control Unit : mm ■ Overview 12 7.7±0.3 (10.0) 29.6±0.3 (1.27) 20.0±0.3 +0.15 R1.8 21.9±0.3 ■ Applications 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 thermal protection circuit • Built-in over current protection circuit • 2 Variable Audio Output (VAO) • VCC operating range : 12.2 V to 27.5 V 0.6 –0.05 (1.27) ■ Features φ3.6 (10.0) 29.75±0.30 28.0±0.3 (1.3) The AN5272 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 • TV ■ Block Diagram Volume 12 Out1 11 NF1 10 VCC GND 8 NF2 7 Out2 6 RF 5 In2 4 VAO2 3 Vol. 2 In1 VAO1 1 Ripple filter 9 Over current thermal protection circuit 1 AN5272 ICs for Audio Common Use ■ Pin Descriptions Pin No. Description Pin No. Description 1 Variable audio output 1 7 Ch.2 output 2 Ch.1 input 8 Negative feedback ch.2 3 Volume control 9 GND 4 Variable audio output 2 10 VCC 5 Ch.2 input 11 Negative feedback ch.1 6 Ripple filter 12 Ch.1 output ■ Absolute Maximum Ratings Parameter Symbol Rating Unit VCC 30 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 12.2 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 Total harmonic distortion Output power *1 *1 Channel balance Max. volume attenuation VAO voltage gain Output noise voltage *1 *1 Conditions 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 % PO THD = 10 % 3.6 4.1 CB VIN = 90 mV −1 0 1 dB Att VIN = 90 mV −70 −64 dB GVAO VIN = 90 mV 12 14 dB VNO Rg = 10 kΩ, Din-Audio Filter 0.6 1.0 mV[rms] Note) *1 : With a filter band from 20 Hz to 20 kHz used. 2 Min 10 W ICs for Audio Common Use AN5272 ■ Application Circuit Example 1 µF 1 µF 10 kΩ Variable audio output 1 100 µF 1000 µF 0.047 µF 10 µF RL = 8 Ω 20 Ω 1 kΩ Variable audio output 2 NF1 11 Out1 12 20 kΩ VCC 10 NF2 8 RF 6 In2 5 1 µF GND 9 5V Out2 7 1 µF VAO2 4 Vol. 3 In1 2 VAO1 1 AN5272 20 kΩ 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. 3 AN5272 ICs for Audio Common Use ■ Technical Information 1.Characteristic Curve Chart PO, THD VIN 30 10 THD 0.1 1 0.01 1 10 Voltage gain GV (dB) PO 1 26 VCC = 18 V RL = 8 Ω VIN = 90 mV Vol. = max. 24 22 1.0 0.8 0.6 0.4 THD 0.2 0.1 1000 100 GV 28 10 100 1k 0 100k 10k Input voltage VIN (mV) Frequency f (Hz) GVAO f PO VCC 10 14 f = 1 kHz THD = 10 % Vol. = max. GV 12 Output power PO (W) Voltage gain GVAO (dB) 8 10 8 VCC = 18 V RL = 8 Ω VIN = 90 mV Vol. = max. 6 4 RL = 8 Ω 6 RL = 16 Ω 4 2 2 0 10 1k 10k 14 12 16 18 20 22 Frequency (Hz) Supply voltage VCC (V) DC volume characteristics PD T a 62.5 7 60 許容損失 PD (W) −20 −30 −40 −50 24 26 28 Rth( j−c) = 2 °C/W Rth( j−a) = 42 °C/W 1. No heat sink 2. 10 °C/W heat sink 3. 5 °C/W heat sink 4. 3 °C/W heat sink 5. 2 °C/W heat sink 6. 1 °C/W heat sink 7. Infinity heat sink 50 −10 41.7 6 40 31.3 5 30 4 25 20 3 17.9 10.4 2 10 −60 1 3.0 0 −70 0 1 2 3 DC volume (V) 4 0 10 100k VCC = 18 V RL = 8 Ω VIN = 90 mV f = 1 kHz 0 Volume attenuation (dB) 100 4 5 0 25 50 75 100 周囲温度 Ta (°C) 125 150 Total harmonic distortion THD (%) 100 VCC = 18 V RL = 8 Ω f = 1 kHz Vol. = max. Total harmonic distortion THD (%) Output power PO (W) 10 GV, THD f ICs for Audio Common Use AN5272 ■ Technical Information (continued) 2.Application Note 1) Voltage gain The voltage gain of the AN5272 can be varied by changing the resistor R2 as shown below : Pin7,12 GVI GV input = 4 dB which is fixed in internal circuit. R1 is always fixed at 20 kΩ. R2 is variable. GVO = 20 log (R1/R2) Pin8 11 R1 Typical values are : R1 = 20 kΩ, R2 = 1 kΩ CNF = 10 µF GVO = 20 log (20 k/1 k) = 26 dB 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 : Volume attenuation AN5272 Microcomputer IC 300 Ω 3 Volume control R4 18 kΩ R5 12 kΩ PWM output C4 2.2 µF 0 Fig. Volume control interface circuit for AN5272 0.6 5 (V) Volume at Pin3 Fig. Volume characteristic of AN5272 3) 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 AN5272 ICs for Audio Common Use ■ Technical Information (continued) 2.Application Note (continued) 4) Power-ON/OFF pop-noise elimination The output pins 7, 12 and VO, during power turn ON and OFF are shown below : VO CRF 33 µF Pin7 & Pin12 VCC 10 RF 6 VCC CVCC 47 µF CRF = 100 µF Turn ON time Turn OFF time The turn ON time in the AN5272 is determined by the capacitance value of CRF. If value of the CRF is smaller, VO would 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 : No. CRF CVCC Recommended Operating VCC Range Unit 1 33 µF 470 µF 14.5 to 27.5 V 2 47 µF 470 µF 12.2 to 27.5 V 3 100 µF 1000 µF 12.2 to 27.5 V 5) Stand-by circuit Stand-by function can be implemented in the AN5272 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 6 ON OFF (Pin7 & Pin12) VO (DC) 100 µF 5V 5V Stand-by Time