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1.

General description

The TDA8948J contains four identical audio power amplifiers. The TDA8948J can be used
as four Single-Ended (SE) channels with a fixed gain of 26 dB, two times Bridge-Tied
Load (BTL) channels with a fixed gain of 32 dB or two times SE channels (26 dB gain)
plus one BTL channel (32 dB gain) operating as a 2.1 system.

The TDA8948J comes in a 17-pin Dil-Bent-Sil (DBS) power package. The TDA8948J is
pin compatible with the TDA8944AJ, TDA8946AJ and TDA8947J.

The TDA8948J contains a unique protection circuit that is solely based on multiple
temperature measurements inside the chip. This gives maximum output power for all
supply voltages and load conditions with no unnecessary audio holes. Almost any supply
voltage and load impedance combination can be made as long as thermal boundary
conditions (number of channels used, external heat sink and ambient temperature) allow
it.

2.

Features

2.1 Functional features

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SE: 1 W to 18 W, BTL: 4 W to 36 W operation possibility (2.1 system)

Soft clipping.

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Standby and mute mode.

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No on/off switching plops.

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Low standby current.

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High supply voltage ripple rejection.

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Outputs short-circuit protected to ground, supply and across the load.

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Thermally protected.

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Pin compatible with TDA8944AJ, TDA8946AJ and TDA8947J.

3.

Applications

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Television

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PC speakers

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Boom box

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Mini and micro audio receivers

TDA8948J

4-channel audio amplifier

Rev. 01 — 27 February 2008

Product data sheet

Summary of Contents for TDA8948J

Page 1: ...put power for all supply voltages and load conditions with no unnecessary audio holes Almost any supply voltage and load impedance combination can be made as long as thermal boundary conditions number...

Page 2: ...therwise specified BTL VCC 17 V Tamb 25 C RL 8 f 1 kHz VMODE1 VCC VMODE2 VCC measured in test circuit Figure 11 unless otherwise specified Symbol Parameter Conditions Min Typ Max Unit VCC supply volta...

Page 3: ...ple and an amplitude of 300 mV RMS which is applied to the positive supply rail 5 Ordering information 6 Block diagram Table 2 Ordering information Type number Package Name Description Version TDA8948...

Page 4: ...tion Symbol Pin Description OUT1 1 non inverted loudspeaker output of channel 1 GND1 2 ground of channels 1 and 2 VCC1 3 supply voltage channels 1 and 2 OUT2 4 inverted loudspeaker output of channel 2...

Page 5: ...equency response and good switch on behavior 8 2 Power amplifier The power amplifier is a BTL and or SE amplifier with an all NPN output stage capable of delivering a peak output current of 4 A Using...

Page 6: ...VCC 17 V RL 8 and THD 0 1 5 The power dissipation can be derived from Figure 8 SE and BTL for a headroom of 0 dB and 12 dB respectively For heat sink calculation at the average listening level a powe...

Page 7: ...Rejection SVRR is measured with an electrolytic capacitor of 150 F on pin SVR using a bandwidth of 20 Hz to 22 kHz Figure 10 illustrates the SVRR as function of the frequency A larger capacitor value...

Page 8: ...be activated when necessary so even during a short circuit condition a certain amount of pulsed current will still be flowing through the short just as much as the power stage can handle without exce...

Page 9: ...fied Symbol Parameter Conditions Min Typ Max Unit Supply VCC supply voltage operating 1 9 17 26 V no clipping signal 2 28 V Iq quiescent current VCC 17 V RL 3 100 145 mA Istb standby current 10 A Outp...

Page 10: ...y fripple and an amplitude of 300 mV RMS which is applied to the positive supply rail 3 Output voltage in mute mode is measured with VMODE1 VMODE2 7 V and Vi 1 V RMS in a bandwidth from 20 Hz to 22 kH...

Page 11: ...105 104 103 102 10 1 coc005 fi 1 kHz 1 1 SE at THD 10 2 2 SE at THD 10 3 3 SE at THD 10 4 4 SE at THD 10 5 8 SE at THD 10 fi 1 kHz 1 16 BTL at THD 10 2 8 BTL at THD 10 3 6 BTL at THD 10 4 4 BTL at TH...

Page 12: ...TL Fig 6 Total harmonic distortion plus noise as a function of output power 102 10 1 10 1 10 2 mce488 10 1 102 1 10 Po W THD N 102 10 1 10 1 10 2 mce487 10 1 1 THD N 10 Po W 102 VCC 17 V Po 1 W RL 4 V...

Page 13: ...on as a function of channel output power per channel worst case all channels driven 010aaa430 0 20 Po W 20 0 4 8 12 16 4 Ptot W 8 12 16 Po W 0 20 16 8 12 4 010aaa432 8 12 4 16 20 Ptot W 0 VCC 17 V RL...

Page 14: ...V RMS A band pass filter of 20 Hz to 22 kHz has been applied Inputs short circuited VCC 17 V RSOURCE 0 Vripple 300 mV RMS A band pass filter of 20 Hz to 22 kHz has been applied Inputs short circuited...

Page 15: ...F 100 nF 470 nF IN3 IN4 OUT3 OUT4 Vi Vi Vi VCC VCC RL8 22 F 2 2 F 10 k 50 k 270 BC547 BC547 7 5 V micro controller 2 15 GND1 GND2 60 k 60 k 3 8 6 60 k 60 k 9 12 14 17 TDA8948J MUTE 3 4 ON 3 4 010aaa05...

Page 16: ...mended to use Schottky diodes to the supply voltage and ground Fig 12 Application diagram with one pin control and reduction of capacitor VCC1 VCC2 16 220 nF IN1 IN2 OUT1 OUT2 220 nF RL4 RL4 470 F 1 4...

Page 17: ...e rejection The respective capacitor location should be as close as possible to the device and grounded to the power ground Proper power supply decoupling also prevents oscillations For suppressing hi...

Page 18: ...the maximum temperature increase divided by the power dissipation Rth tot Tj max Tamb max P At VCC 17 V and RL 4 4 SE the measured worst case sine wave dissipation is 17 W see Figure 8 For Tj max 150...

Page 19: ...applicable Tamb 25 C external heat sink of 4 3 K W 1 RL 1 2 RL 2 3 RL 3 4 RL 4 5 RL 8 Tamb 25 C external heat sink of 4 3 K W 1 RL 2 2 RL 4 3 RL 6 4 RL 8 5 RL 16 a 4 times various SE loads with music...

Page 20: ...ions Note 1 Plastic or metal protrusions of 0 25 mm maximum per side are not included SOT243 1 0 5 10 mm scale D L E A c A2 L3 Q w M bp 1 d D Z e e x h 1 17 j Eh non concave 99 12 17 03 03 12 DBS17P p...

Page 21: ...older The wave soldering process is suitable for the following Through hole components Leaded or leadless SMDs which are glued to the surface of the printed circuit board Not all SMDs can be wave sold...

Page 22: ...It is imperative that the peak temperature is high enough for the solder to make reliable solder joints a solder paste characteristic In addition the peak temperature must be low enough that the packa...

Page 23: ...rther information on temperature profiles refer to Application Note AN10365 Surface mount reflow soldering description MSL Moisture Sensitivity Level Fig 16 Temperature profiles for large and small co...

Page 24: ...data sheet Rev 01 27 February 2008 24 of 26 NXP Semiconductors TDA8948J 4 channel audio amplifier 17 Revision history Table 14 Revision history Document ID Release date Data sheet status Change notic...

Page 25: ...to result in personal injury death or severe property or environmental damage NXP Semiconductors accepts no liability for inclusion and or use of NXP Semiconductors products in such equipment or appli...

Page 26: ...figuration 5 8 2 Power amplifier 5 8 2 1 Output power measurement 6 8 2 2 Headroom 6 8 3 Mode selection 6 8 4 Supply voltage ripple rejection 7 8 5 Built in protection circuits 8 9 Limiting values 8 1...

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