AN5273

ICs for Audio Common Use AN5273 4.0 W × 2 (18 V, 8 Ω) Power Amplifier with Mute Function and Volume Control Unit : mm 29.75±0.30 28.0±0.3 20.0±0.3 s Features • Built-in DC volume control • Built-in mute circuit • Built-in thermal protection circuit • Built-in over current protection circuit • VCC operating range : 12.2 V to 27.5 V R1.8 0.6 +0.10 0.25 –0.05 2.54 1 0.6 –0.05 (1.27) (10.0) +0.15 (12.5) 1.2±0.1 1.45±0.15 (1.2) 19.1±0.3 21.9±0.3 s Applications • TV HSIP012-P-0000A s Block Diagram Volume Over current thermal protection circuit 10 11 12 Ripple filter 1 2 3 4 5 6 7 8 In1 Mute Vol. N.C. In2 RF Out2 NF2 GND 9 VCC Out1 NF1 1.80±0.15 3.5±0.3 29.6±0.3 The AN5273 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. 12 (10.0) s Overview 7.7±0.3 φ3.6 (1.27) (1.3) 1 AN5273 s Pin Descriptions Pin No. 1 2 3 4 5 6 Description Mute control Ch.1 input Volume control N.C. Ch.2 input Ripple filter Pin No. 7 8 9 10 11 12 ICs for Audio Common Use Description Ch.2 output Negative feedback ch.2 GND VCC Negative feedback ch.1 Ch.1 output s Absolute Maximum Ratings Parameter Supply voltage Supply current Power dissipation *2 *1 Symbol VCC ICC PD Topr Tstg Rating 30 3.5 37.5 −25 to +75 −55 to +150 Unit V A W °C °C Operating ambient temperature Storage temperature *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. s Recommended Operating Range Parameter Supply voltage Symbol VCC Range 12.2 to 27.5 Unit V s Electrical Characteristics at VCC = 18 V, f = 1 kHz, RL = 8 Ω, Ta = 25 °C Parameter Quiescent current Voltage gain Total harmonic distortion Output power *1 *1 Symbol ICQ GV THD PO CB *1 Conditions No input signal VIN = 90 mV VIN = 90 mV THD = 10 % VIN = 90 mV VIN = 90 mV VIN = 90 mV Rg = 10 kΩ, Din-Audio Filter Min 17 28 Typ 25 30 0.3 Max 33 32 1.0 Unit mA dB % W 3.6 −1 4.1 0 −70 −70 0.6 1 −64 −64 Channel balance Max. volume attenuation Mute attenuation *1 *1 dB dB dB Att MAtt VNO Output noise voltage 1.0 mV[rms] Note) *1 : With a filter band from 20 Hz to 20 kHz used. 2 ICs for Audio Common Use s Application Circuit Example AN5273 AN5273 VCC 10 NF1 11 Out1 12 RF 6 4 GND 9 Mute 1 Out2 7 N.C. NF2 8 In1 2 Vol. 3 In2 5 100 kΩ Audio mute 5V 1 µF 3.3 µF 5V 1 µF 100 µF 1000 µF RL = 8 Ω 20 kΩ 0.047 µF 20 Ω 10 µF 1 kΩ 18 V 10 µF 1000 µF 1 kΩ 20 kΩ 0.047 µF 20 Ω 1000 µF RL = 8 Ω 10 kΩ s 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 AN5273 s Technical Information 1.Characteristic Curve Chart PO, THD  VIN 10 VCC = 18 V RL = 8 Ω f = 1 kHz Vol. = max. PO 100 30 ICs for Audio Common Use GV, THD  f Total harmonic distortion THD (%) 28 1 10 26 24 22 VCC = 18 V RL = 8 Ω VIN = 90 mV Vol. = max. 1.0 0.8 0.6 0.4 THD 0.2 0.1 THD 1 0.01 1 10 100 0.1 1000 10 100 1k 10k 0 100k Input voltage VIN (mV) Frequency f (Hz) DC volume characteristics 10 0 VCC = 18 V RL = 8 Ω VIN = 90 mV f = 1 kHz f = 1 kHz THD = 10 % Vol. = max. 8 PO  VCC Volume attenuation (dB) −20 −30 −40 −50 Output power PO (W) −10 RL = 8 Ω 6 4 RL = 16 Ω 2 −60 −70 0 1 2 3 4 5 0 10 12 14 16 18 20 22 24 26 28 DC volume (V) Supply voltage VCC (V) PD  Ta 62.5 7 60 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 Power dissipation PD (W) 50 41.7 6 40 31.3 5 30 4 25 20 3 17.9 10.4 2 10 3.0 0 0 1 25 50 75 100 125 150 Ambient temperature Ta (°C) 4 Total harmonic distortion THD (%) GV Output power PO (W) Voltage gain GV (dB) ICs for Audio Common Use s Technical Information (continued) 2.Application Note 1) Voltage gain The voltage gain of the AN5273 can be varied by changing the resistor R2 as shown below : Pin7,12 Pin8 11 AN5273 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) R1 CNF = 10 µF R2 Typical values are : R1 = 20 kΩ, R2 = 1 kΩ GVO = 20 log (20 k/1 k) = 26 dB 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 : AN5273 Microcomputer IC R4 18 kΩ C4 2.2 µF R5 12 kΩ PWM output Volume attenuation 300 Ω 3 Volume control Fig. Volume control interface circuit for AN5273 5 (V) Volume at Pin3 Fig. Volume characteristic of AN5273 0 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 ZMUTE C 1.0 µF The purpose of the Mute is to attenuate the AC signal before it goes to the output. R 100 kΩ 1 20 kΩ Q1 0V Threshold voltage at Pin1 : Mute OFF 1.8 V 2.1 V Mute ON 5V 5 AN5273 s Technical Information (continued) 2.Application Note (continued) ICs for Audio Common Use 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 C R 0.047 µF 20 Ω Pin7 12 RL = 8 Ω 5) Power-ON/OFF pop-noise elimination The output pins 7, 12 and VO, during power turn ON and OFF are shown below : VCC VO 33 µF Pin7 & Pin12 47 µF CRF = 100 µF Turn ON time Turn OFF time CRF CVCC The turn ON time in the AN5273 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 : No. 1 2 3 CRF 33 µF 47 µF 100 µF CVCC 470 µF 470 µF 1000 µF Recommended Operating VCC Range 14.5 to 27.5 12.2 to 27.5 12.2 to 27.5 Unit V V V 6 VCC 10 RF 6 ICs for Audio Common Use s Technical Information (continued) 2.Application Note (continued) AN5273 6) Stand-by circuit Stand-by function can be implemented in the AN5273 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 100 µF 5V 5V Stand-by Time (Pin7 & Pin12) VO (DC) OFF 7