View PAM8803_7919026.PDF datasheet online --- IC-ON-LINE

Datasheet File OCR Text:

key features applications 3w output at 10% thd with a 4 load and 5v power supply filterless, low quiescent current and low emi low thd+n 64-step digital volume control superior low noise low pop noise efficiency up to 90% short circuit protection thermal shutdown few external components to save space and cost lcd monitors/tv projectors notebook computers portable speakers portable dvd players, game machines cellular phones/speaker phones directly it can extend the battery life, ideal for portable applications. general description the PAM8803 is a 3w, class-d audio amplifier with 64-step digital volume control. it offers low thd+n, allowing it to produce high-quality sound reproduction. the new filterless architecture allows the device to drive the speaker , without needing low-pass output filters which will save 30% system cost and 75% pcb area. with the same numbers of external components, the efficiency of the PAM8803 is much better than class-ab cousins. the PAM8803 is available in a ssop-24 package. , pb-free package PAM8803 3w filterless stereo class-d audio amplifier with digital volume control 1 www.poweranalog.com 0 10 20 30 40 50 60 70 80 90 100 0 0.5 1 1.5 2 2.5 3 output pow er(w) efficiency(%) r l =8 r l =4 efficiency vs output power typical application vdd -out_l pgnd pgnd +out_l pvdd pvdd pgnd pgnd +out _r -out_r mute inl inr gnd shdn ncncncnc vref dn up rst PAM8803 7 c1 1f vd d c2 1f c3 10f c4 10f c5 1f pvdd pvdd 5 20 sp_l sp_ r 23 18 22 23 9111216 4 1 21 24 c6 0.47f c7 0.47f in l inr c8 1f mute shdn s1 s2 s3 6 19 15 13 14 10 817 fcc class b limit radiated emissions , power analog microelectronics inc mute on shdn on 12/2009 rev 1.4
block diagram 2 pin configuration & marking information top view ssop-24 vdd/2 vdd/2 interface control attenuation decoder vdd inr up dn rst mute shdn inl gnd pvdd pgnd -out_l +out_l vref -out_r +out_r pgnd pvdd modulator driver internal oscillator osc bias and references modulator driver thermal protection current protection + - + - x: internal code y: year ww: week ll: internal code , power analog microelectronics inc www.poweranalog.com PAM8803 3w filterless stereo class-d audio amplifier with digital volume control -out_l pgnd pgnd +out_l pvdd mute vdd inl nc vref nc nc dn up rst nc inr gnd shdn pvdd +out_r pgnd pgnd -out_r PAM8803 xxxywwll 17 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 18 19 20 21 22 23 24 12/2009 rev 1.4
pin descriptions 3 absolute maximum ratings these are stress ratings only and functional operation is not implied exposure to absolute maximum ratings for prolonged time periods may affect device reliability all voltages are with respect to ground . . . supply voltage at no input signal...................6.0v input voltage.............................-0.3v to v +0.3v storage temperature.....................-65 to 150 soldering temperature....................... dd maximum junction temperature..................150c c c 300c, 5sec pin number pin name description 1 -out_l left channel negative output 2 pgnd power gnd 3 pgnd power gnd 4 +out_l left channel positive output 5 pvdd power vdd 6 mu te mute control input ac ti ve low , pull-up 7 vdd analog vdd 8 inl left channel input 9 nc no connect 10 vref internal analog reference, connect a bypass capacitor from vref to gnd 11 nc no connect 12 nc no connect 13 dn volume down control (active low) 14 up volume up control (active low) 15 rst volume controller reset (active low) 16 nc no connect 17 inr right channel input 18 gnd analog gnd 19 shdn shutdown control input(active low), pull-down 20 pvdd power vdd 21 +out_r right channel positive output 22 pgnd power gnd 23 pgnd power gnd 24 -out_r right channel negative output , power analog microelectronics inc www.poweranalog.com PAM8803 3w filterless stereo class-d audio amplifier with digital volume control recommended operating conditions supply voltage range........................ ambient temperature range...........-40 to 85 junction temperature range.........-40 to 125 2.2v to 5.5v c c c c 12/2009 rev 1.4
thermal information 4 electrical characteristic v =5v, gain = 18db, r =8 t =25 unless otherwise noted. dd l a , c parameter symbol package maximum unit thermal resistance (junction to ambient) ja ssop-24 96 c/w , power analog microelectronics inc parameter sym bol conditions min typ max units supply voltage range v dd 2.2 5.5 v no load 7 15 r l =8 8 quiescent current i q r l =4 8.5 ma mute current i mute v mute =0v 2.5 4 ma shutdown current i shdn v shdn =0v 0.5 10 a shdn input high v sh 1.2 shdn input low v sl 0.5 v mute input high v mh 1.2 mute input low v ml 0.5 v output offset voltage v os no load 120 300 mv p mosfet 0.3 0.40 drain-source on-state resistance r ds (on) i ds =0.5a n mosfet 0.22 0.35 r l = 8,thd=1% 1.1 1.3 r l = 8,thd=10% 1.5 1.7 r l = 4,thd=1% 1.9 2.1 output power p o f=1khz r l = 4,thd=10% 2.8 3.0 w r l =8, p o =0.5w 0.19 r l =8, p o =1.0w 0.22 r l =4, p o =1.0w 0.17 total harmonic distortion plus noise thd+n r l =4, p o =2.0w 0.25 % power supply ripple rejection psrr no input, f=1khz, vpp=200mv 45 55 db channel separation cs p o =1w, r l =4 6080db oscillator fre quency f osc 170 210 250 khz p o =1.7w, f=1khz, r l =8 85 89 % efficiency p o =3.0w, f=1khz, r l =4 80 83 % r l =4 85 db signal noise ratio snr f =22 to 22khz thd=1% r l =8 87 db under voltage lock-out uvlo 1.95 v over temperature protection otp 150 c over temperature hysteresis oth 60 c www.poweranalog.com PAM8803 3w filterless stereo class-d audio amplifier with digital volume control 12/2009 rev 1.4
5 typical operating characteristics (t =25c) a 3. thd+n vs output power v =5v,r=4 ,gain=18db dd l 4. thd+n vs output power v =5v,r=8 ,gain=18db dd l 0. 0 1 1 0 0 0. 0 2 0. 0 5 0 .1 0 .2 0 .5 1 2 5 1 0 2 0 5 0 % 2 0 m 4 5 0m 1 0 0m 2 00 m5 00 m1 2 w f=100hz f=10khz f=1khz 0. 01 100 0. 02 0. 05 0. 1 0. 2 0. 5 1 2 5 10 20 50 % 20m 4 50m 100m 200m 500m 1 2 w f=100hz f=10khz f=1khz 5. thd+n vs frequency v =5v,r=4 ,gain=18db dd l 0. 01 100 0. 02 0. 05 0. 1 0. 2 0. 5 1 2 5 10 20 50 % 20 20k 50 100 200 500 1k 2k 5k 10k h z po=2w po=1.5w po=2w 6. thd+n vs frequency v =5v,r=8 ,gain=18db dd l 0. 01 100 0. 02 0. 05 0. 1 0. 2 0. 5 1 2 5 10 20 50 % 20 20k 50 100 200 500 1k 2k 5k 10k h z po=2w po=0.5w po=1w , power analog microelectronics inc 1. thd+n vs output power r =4 , gain = 18db l 2. thd+n vs output power r =8 , gain = 18db l www.poweranalog.com 0.01 30 0.02 0.05 0.1 0.2 0.5 1 2 5 10 20 % 10m 4 20m 50m 100m 200m 500m 1 2 w v =2.5v dd v =3.6v dd v=5v dd 0.01 30 0.02 0.05 0.1 0.2 0.5 1 2 5 10 % 10 m 4 2 0m 5 0m 1 00 m 20 0m 50 0m 1 2 w v =2.5v dd v =3.6v dd v=5v dd PAM8803 3w filterless stereo class-d audio amplifier with digital volume control 12/2009 rev 1.4
6 typical operating characteristics (continued) 11. fft of noise output -150 +0 -140 -130 -120 -110 -100 -90 -80 -70 -60 -50 -40 -30 -20 -10 d b v 20 20k 50 100 200 500 1k 2k 5k 10k h z v =5v, gain = 18db dd 12.channel separation v =5v,r=4 ,p =1.0w,gain=18db dd l o - 110 -40 - 100 -90 -80 -70 -60 -50 d b 20 20k 50 100 200 500 1k 2k 5k 10k h z rtol ltor 9. frequency response v =5v, gain =18db dd 10. power supply ripple rejection vs frequency -70 +20 -60 -50 -40 -30 -20 -10 +0 +10 d b 10 20 k 20 50 100 200 50 01k 2k 5k10 k h z v =5v with 200mvpp ripple dd + 1 5 + 3 5 + 2 0 + 2 5 + 3 0 d b r 2 02 0 k 5 01 0 02 0 05 0 01 k2 k5 k1 0 k h z hz 7. thd+n vs. frequency po=0.1w,r =8 gain=18db l , po=0.8w,r =4 gain=18db l , 0. 01 100 0. 02 0. 05 0. 1 0. 2 0. 5 1 2 5 10 20 50 % 20 20k 50 100 200 500 1k 2k 5k 10k h z v=5v dd v =3.3v dd 8. thd+n vs. frequency 0. 01 100 0. 02 0. 05 0. 1 0. 2 0. 5 1 2 5 10 20 50 % 20 20k 50 100 200 500 1k 2k 5k 10k h z v=5v dd v =3.3v dd , power analog microelectronics inc www.poweranalog.com PAM8803 3w filterless stereo class-d audio amplifier with digital volume control 12/2009 rev 1.4
7 gain setting (v =5v) dd *power on gain or gain after reset. gain could have 1db deviation device to device. note: typical operating characteristics (continued) 13. output power vs power supply r=4 l , power analog microelectronics inc www.poweranalog.com PAM8803 3w filterless stereo class-d audio amplifier with digital volume control 0 0.5 1 1.5 2 2.5 3 3.5 4 23456 supply voltage (v) output power(w) 10%?d 1%?d 0 0.5 1 1.5 2 2.5 23456 supply voltage (v) output power (w) 14. output power vs power supply r=8 l 10%?d 1%?d step gain (db) step gain (db) step gain (db) step gain (db) 1 -75.0 17 4.8 33 11.2 49 17.6 2 -39.7 18 5.1 34 11.6 50 18.0 3 -34.0 19 5.5 35 12.0 51 18.4 4 -28.2 20 5.9 36 12.3 52 18.8 5 -22.4 21 6.3 37 12.7 53 19.2 6 -16.5 22 6.7 38 13.2 54 19.6 7 -10.5 23 7.1 39 13.6 55 20.0 8 -8.0 24 7.5 40 14.0 56 20.4 9 -5.5 25 7.9 41 14.4 57 20.9 10 -2.9 26 8.3 42 14.8 58 21.3 11 -0.4 27 8.7 43 15.2 59 21.7 12 1.1 28 9.1 44 15.6 60 22.1 13 2.6* 29 9.6 45 16.0 61 22.5 14 3.6 3010.0 4616.4 6222.9 15 4.0 3110.4 4716.8 6323.4 16 4.4 3210.7 4817.2 6423.8 12/2009 rev 1.4
8 application notice 1 when PAM8803 works without filter, we must connect the speaker before turn on. else, it will be easy to damage the chip. 2 when PAM8803 works without filter, it will be best that adding a ferrite chip bead at the outgoing line of speaker in order to suppress possible electromagnetic interference . 3 the absolute maximum rating of operation voltage is 6.0v. while using 6v power regulator, even the chip can deliver 4w sine wave with a 4 ohm speaker, it is not recommended for long term using due to the heat dissipation. but if the input signal is a music signal, then it can work in long term since the average power output is much less than 4w. when using dry battery cell, we should notice that if the battery cell is 4 new dry batteries or alkaline batteries, even the voltage will be over 6v, it still can work safety. since the output voltage of the 4 pack of new dry batteries will be reduced very quickly after turn on due to the internal resistance of the battery. there is no dangerous of damaging the chip when playing music or speech, even use 4 new dry batteries. to reduce the effect of the increasing of internal resistance of battery after long term discharging, it is recommended to connect a 1000uf electrolytic capacitor between the power supply and the ground. 4 because digital volume control has big gain, we can not make input signal too high to cause the clipping of the output signal when increase volume, also it may damage the chip. test setup for performance testing notes 1. the ap aux-0025 low pass filter is necessary for every class-d amplifier measurement done by ap analyzer. 2. two 22 h inductors are used in series with load resistor to emulate the small speaker for efficiency and quiescent current measurement. ap system one generator PAM8803 demo board +out input load ap low pass filter aux-0025 ap system one analyzer gnd -out vdd power supply , power analog microelectronics inc www.poweranalog.com PAM8803 3w filterless stereo class-d audio amplifier with digital volume control 12/2009 rev 1.4
9 maximum gain digital volume control (dvc) mute operation as shown in block diagram(page 2),the PAM8803 has two internal amplifiers stage. the first stage's gain is externally configurable, while the second stage's is internally fixed in a fixed-gain, inverting configuration. the closed-loop gain of the first stage is set by selecting the ratio of r to r while the second stage's gain is fixed at 2x. consequently, the differential gain for the ic is a =20*log [2*(r /r )] the PAM8803 sets maximum r =218k minimum r =27k , thus the maximum closed- gain is 24db. the PAM8803 features a digital volume control which consists of the up, dn and rst pins. an internal clock is used where the clock frequency value is determined from the following formula: f=f /2 the oscillator frequency f value is 200khz typical,with 20% tolerance.the dvcs clock frequency is 33hz (cycle time ) typical. volume changes are then effected by toggling either the up or dn pins with a logic low. after a period of 3.5 clocks pulses with either the up or dn pins held low, the volume will change to the next specified step, either up or dn, and followed by a short delay. this delay decreases the longer the line is held low, eventually reaching a delay of zero. the delay allows the user to pull the up or dn terminal low once for one volume change, or hold down to ramp several volume changes. the delay is optimally configured for push button volume control. if either the up or dn pin remains low after the first volume transition the volume will change again, but this time after 9.5 clock pulses. the followed transition occurs at 2 clock pulses for each volume transition. this is intended to provide the user with a volume control that pauses briefly after initial application, and then slowly increases the rate of volume change as it is continuously applied. this cycle is shown in the timing diagram shown in figure 1. there are 64 discrete gain settings ranging from +24db maximum to -75db minimum. upon device power on or applied a logic low to the rst pin, the amplifier's gain is set to a default value of 2.6db. however, when coming out of mute mode, the PAM8803 will revert back to its previous gain setting. volume levels for each step vary and are specified in gain setting table on page 7. if both the up and dn pins are held high, no volume change will occur. trigger points for the up and dn pins are at 70% of v minimum for a logic high, and 20% of v maximum for a logic low. it is recommended, however, to toggle up anddnbetweenv andgndforbest performance. figure 1.timming diagram the pin is an input for controlling the output state of the PAM8803. a logic low on this pin disables the outputs, and a logic high on this pin enables the outputs. this pin may be used as a quick disable or enable of the outputs without a volume fade. quiescent current is listed in the electrical characteristic table. the pin can be left floating due to the pull-up internal. f i vd f i f i clk osc osc dd dd dd 13 mute mute and 30ms in order to reduce power consumption while not in use, the PAM8803 contains shutdown circuitry that is used to turn off the amplifier's bias circuitry. this shutdown feature turns the amplifier off when logic low is placed on the pin. by switching the pin connected to gnd, the PAM8803 supply current draw will be minimized in idle mode. the pin cannot be left floating due to the pull-down internal. shutdown operation shdn shdn shdn application information , power analog microelectronics inc www.poweranalog.com PAM8803 3w filterless stereo class-d audio amplifier with digital volume control 3.5 cycles 9.5 cycles 2 cycles 2 cycles up/dn volume level 12/2009 rev 1.4
10 power supply decoupling input capacitor (c ) analog reference bypass capacitor (c ) the PAM8803 is a high performance cmos audio amplifier that requires adequate power supply decoupling to ensure the output thd and psrr are as low as possible. power supply decoupling is affecting low frequency response. optimum decoupling is achieved by using two capacitors of different types that target different types of noise on the power supply leads. for higher frequency transients, spikes, or digital hash on the line, a good low equivalent-series- resistance (esr) ceramic capacitor, typically 1.0f, placed as close as possible to the device v terminal works best. for filtering lower- frequency noise signals, a larger capacitor of or greater placed near the audio power amplifier is recommended. large input capacitors are both expensive and space hungry for portable designs. clearly, a certain sized capacitor is needed to couple in low frequencies without severe attenuation. but in many cases the speakers used in portable systems, whether internal or external, have little ability to reproduce signals below 100hz to 150hz. thus, using a large input capacitor may not increase actual system performance. in this case, input capacitor (c ) and input resistance (r ) of the amplifier form a high-pass filter with the corner frequency determined equation below, in addition to system cost and size, click and pop performance is affected by the size of the input coupling capacitor, c . a larger input coupling capacitor requires more charge to reach its quiescent dc voltage (nominally 1/2 v ). this charge comes from the internal circuit via the feedback and is apt to create pops upon device enable. thus, by minimizing the capacitor size based on necessary low frequency response, turn-on pops can be minimized. the analog reference bypass capacitor (c ) is the most critical capacitor and serves several important functions. during start-up or recovery from shutdown mode, c determines the rate at which the amplifier starts up. the second function is to reduce noise produced by the power supply caused by coupling into the output drive signal. this noise is from the internal analog reference to the amplifier, which appears as degraded psrr and thd+n. bypass capacitor (c ) values of 0.47f to 1.0f ceramic is recommended for the best thd and noise performance. increasing the bypass capacitor reduces clicking and popping noise from power on/off and entering and leaving shutdown. dd i i i dd byp byp byp i byp 10f (ceramic) the PAM8803 incorporates circuitry designed to detect when the supply voltage is low. when the supply voltage drops to 1.85v or below, the PAM8803 outputs are disable, and the device comes out of this state and starts to normal functional when the supply voltage increases. the PAM8803 has short circuit protection circuitry on the outputs that prevents damage to the device during output-to-output and output- to-gnd short. when a short circuit is detected on the outputs, the outputs are disable immediately. if the short was removed, the device activates again. thermal protection on the PAM8803 prevents damage to the device when the internal die temperature exceeds 150c. there is a 15 degree tolerance on this trip point from device to device. once the die temperature exceeds the thermal set point, the device outputs are disabled. this is not a latched fault. the thermal fault is cleared once the temperature of the die is reduced by 60c. this large hysteresis will prevent motor boating sound well and the device begins normal operation at this point with no external system interaction. a simple solution is to put an additional capacitor 1000uf at power supply terminal for power line coupling if the traces from amplifier to speakers are short (<20cm). under voltage lock-out (uvlo) short circuit protection (scp) over temperature protection how to reduce emi (electro magnetic interference) c ii 1 f= 2r c , power analog microelectronics inc www.poweranalog.com PAM8803 3w filterless stereo class-d audio amplifier with digital volume control 12/2009 rev 1.4
most applications require a ferrite bead filter which shows at figure 3. the ferrite filter reduces emi around 1 mhz and higher. when selecting a ferrite bead, choose one with high impedance at high frequencies, but low impedance at low frequencies. figure 3: ferrite bead filter to reduce emi at this stage it is paramount that we acknowledge the need for separate grounds. noise currents in the output power stage need to be returned to output noise ground and nowhere else. were these currents to circulate elsewhere, they may get into the power supply, the signal ground, etc, worse yet, they may form a loop and radiate noise. any of these instances results in degraded amplifier performance. the logical returns for the output noise currents associated with class d switching are the respective pgnd pins for each channel. the switch state diagram illustrates that pgnd is instrumental in nearly every switch state. this is the perfect point to which the output noise ground trace should return. also note that output noise ground is channel specific. a two channels amplifier has two mutually exclusive channels and consequently must have two mutually exclusive output noise ground traces. the layout of the PAM8803 offers separate pgnd connections for each channel and in some cases each side of the bridge. output noise grounds must tie to system ground at the power in exclusively. signal currents for the inputs, reference, etc need to be returned to quite ground. this ground only ties to the signal components and the gnd pin. gnd then ties to system ground. as same to the ground, vdd and each channel pvdd need to be separated and tied together at the system power supply. recommend that all the trace could be routed as short and thick as possible. for the power line layout, just imagine water stream, any barricade placed in the trace (shows in figure 4) could result in the bad performance of the amplifier. figure 4 the power supply decoupling capacitors need to be placed as close to vdd and pvdd pins as possible. the inputs need to be routed away from the noisy trace. the vref bypass capacitor also needs to be close to the pin of ic very much. pcb layout guidelines grounding power supply line components placement 11 220pf 220pf out+ out- ferrite bead ferrite bead , power analog microelectronics inc www.poweranalog.com figure 5: layout example pcb top layer pcb bottom layer PAM8803 3w filterless stereo class-d audio amplifier with digital volume control 12/2009 rev 1.4
ordering information 12 package type PAM8803 x x x number of pins , power analog microelectronics inc part number marking package type shipping package PAM8803nhr PAM8803 xxxywwll ssop-24 2,500 units/tape & reel www.poweranalog.com shipping package PAM8803 3w filterless stereo class-d audio amplifier with digital volume control 12/2009 rev 1.4
outline dimension 13 ssop-24 , power analog microelectronics inc www.poweranalog.com PAM8803 3w filterless stereo class-d audio amplifier with digital volume control 12/2009 rev 1.4

▲Up To Search▲

Price & Availability of PAM8803

	To Download PAM8803 Datasheet File
If you can't view the Datasheet, Please click here to try to view without PDF Reader .