tea2025b tea2025d stereo audio amplifier dual or bridge connection modes few external components supply voltage down to 3v high channel separation very low switch on/off noise max gain of 45db with adjust exter- nal resistor soft clipping thermal protection 3v < v cc < 15v p = 2 1w, v cc = 6v, r l = 4 w p = 2 2.3w, v cc = 9v, r l = 4 w p = 2 0.1w, v cc = 3v, r l = 4 w description the tea2025b/d is a monolithic integrated circuit in 12+2+2 powerdip and 12+4+4 so, intended for use as dual or bridge power audio amplifier port- able radio cassette players. september 2003 symbol parameter test conditions unit v s supply voltage 15 v i o ouput peak current 1.5 a t j junction temperature 150 c t stg storage temperature 150 c absolute maximum ratings decoupling 1 1 - + 2 - + 2 thermal protect. start circuit 10k w 10k w 50 w 50 w 5k w 50 w svr in 2+ feed gnd gnd boot 2 out 2 bridge v s+ out 1 boot 1 gnd gnd feed in 1+ gnd(sub) d94au120 block diagram powerdip 12+2+2 so20 (12+4+4) ordering numbers: tea2025b (pdip) tea2025d (so) ? 1/9
bridge out.2 boot.2 gnd gnd feedback in.2 (+) svr +vs out.1 boot.1 gnd gnd feedback in.1 (+) gnd (sub.) 1 2 3 4 5 6 7 8 16 15 14 13 12 11 10 9 powerdip 12+2+2 pin connection (top view) bridge out 2 boot 2 gnd gnd gnd gnd feedback in 2(+) 1 3 2 4 5 6 7 8 9 in 1(+) feedback gnd gnd gnd gnd boot 1 out 1 v cc 20 19 18 17 16 14 15 13 12 d94au119 svr 10 gnd(sub) 11 so 12+4+4 pin connection (top view) symbol description so 12+4+4 (*) pdip 12+2+2 (**) unit r th j-case r th j-amb thermal resistance junction-case thermal resistance junction-ambient max max 15 65 15 60 c/w c/w (*) the r th j-amb is measured with 4sq cm copper area heatsink (**) the r th j-amb is measured on devices bonded on a 10 x 5 x 0.15cm glass-epoxy substrate with a 35 m m thick copper surface of 5 cm 2 . thermal data tea2025b - tea2025d 2/9
electrical characteristics (t amb = 25 c, v cc = 9v, stereo unless otherwise specified) symbol parameter test conditions min. typ. max. unit v s supply voltage 3 12 v i q quiescent current 35 50 ma v o quiescent output voltage 4.5 v a v voltage gain stereo bridge 43 49 45 51 47 53 db d a v voltage gain difference 1db r j input impedance 30 k w po output power (d = 10%) stereo 8 (per channel) 9v 9v 6v 6v 6v 6v 3v 3v 12v 4 w 8 w 4 w 8 w 16 w 32 w 4 w 32 w 8 w 1.7 0.7 2.3 1.3 1 0.6 0.25 0.13 0.1 0.02 2.4 w bridge 9v 6v 6v 3v 3v 8 w 4 w 8 w 16 w 32 w 4.7 2.8 1.5 0.18 0.06 w d distortion vs = 9v; r l = 4 w stereo bridge 0.3 0.5 1.5 % svr supply voltage rejection f = 100hz, v r = 0.5v, r g = 0 40 46 db e n ( in ) input noise voltage r g = 0 r g = 10 4 w 1.5 3 3 6 mv ct cross-talk f = 1khz, r g = 10k w 40 52 db term. n (pdip) 12345678910111213141516 dc volt (v) 0.04 4.5 8.9 0 0 0.6 0.04 8.5 0 0.04 0.6 0 0 8.9 4.5 9 figure 1: bridge application (powerdip) figure 2: stereo application (powerdip) c6 c4 c8 c5 c7 c9 c2 c11 c3 c1 c10 tea2025b - tea2025d 3/9
10 20 30 40 50 3 6 9 12 15 i(ma) vs(v) stereo figure 3: supply current vs. supply voltage (r l = 4 w ) 0 0.5 1 1.5 2 2.5 3 3.5 3 6 9 12 15 po(w) vs(v) stereo rl=4ohm rl=8ohm rl=16ohm figure 5: output power vs. supply voltage (thd = 10%, f = 1khz) 0.1 1 10 0 0.2 0.4 0.6 0.8 1 thd(%) po(w) stereo rl=4 ohm rl=16ohm rl=8ohm figure 6: thd versus output power (f = 1khz, v s = 6v) 0 1 2 3 4 5 6 7 8 3691215 vo(v) vs(v) vs(v) stereo figure 4: output voltage vs. supply voltage tea2025b - tea2025d 4/9
application information input capacitor input capacitor is pnp type allowing source to be referenced to ground. in this way no input coupling capacitor is required. however, a series capacitor (0.22 uf)to the input side can be useful in case of noise due to variable resistor contact. bootstrap the bootstrap connection allows to increase the output swing. the suggested value for the bootstrap capacitors (100uf) avoids a reduction of the output signal also at low frequencies and low supply voltages. voltage gain adjust stereo mode the voltage gain is determined by on-chip resis- tors r1 and r2 together with the external rfc1 series connected between pin 6 (11) and ground. the frequency response is given approximated by: v out v in = r1 rf + r2 + 1 jwc1 with rf=0, c1=100 uf, the gain results 46 db with pole at f=32 hz. the purpose of rf is to reduce the gain. it is rec- ommended to not reduce it under 36 db. bridge mode the bridge configuration is realized very easily thanks to an internal voltage divider which pro- vides (at pin 1) the ch 1 output signal after reduc- tion. it is enough to connect pin 6 (inverting input of ch 2) with a capacitor to pin 1 and to connect to ground the pin 7. the total gain of the bridge is given by: v out v in = r1 rf + r2 + 1 jwc1 ( 1 + r3 r4 r1 r2 + r4 + 1 jwc1 ) and with the suggested values (c1 = c2 = 100 m f, rf= 0) means: gv = 52 db with first pole at f = 32 hz output capacitors. the low cut off frequency due to output capacitor depending on the load is given by: f l = 1 2 p c out r l with c out 470 m f and r l = 4 ohm it means f l = 80 hz. pop noise most amplifiers similar to tea 2025b need exter- nal resistors between dc outputs and ground in order to optimize the pop on/off performance and crossover distortion. the tea 2025b solution allows to save compo- nents because of such resistors (800 ohm)are in- cluded into the chip. figure 7 figure 8 figure 9 tea2025b - tea2025d 5/9
stability a good layout is recommended in order to avoid oscillations. generally the designer must pay attention on the following points: - short wires of components and short connec- tions. - no ground loops. - bypass of supply voltage with capacitors as nearest as possible to the supply i.c.pin.the low value(poliester)capacitors must have good temperature and frequency charac- teristics. - no sockets. 2) the heatsink can have a smaller factor of safety compared with that of a conventional circuit. there is no device damage in the case of ex- cessive junction temperature: all that happens is that p o (and therefore p tot ) and id are re- duced. application suggestion the recommended values of the components are those shown on stereo application circuit of fig. 2 different values can be used, the follow- ing table can help the designer. component recommended value purpose larger than smaller than c1,c2 0.22 m f input dc decoupling in case of slider contact noise of variable resistor c3 100 m f ripple rejecton degradation of svr, increase of thd at low frequency and low voltage c4,c5 100 m f bootstrap c6,c7 470 m f output dc decoupling increase of low frequency cut- off c8,c9 0.15 m f frequency stability danger of oscillations c10, c11 100 m f inverting input dc decoupling increase of low frequency cut- off tea2025b - tea2025d 6/9
11 0 11 20 a e b d e l k h a1 c so20mec h x 45? so20 dim. mm inch min. typ. max. min. typ. max. a 2.35 2.65 0.093 0.104 a1 0.1 0.3 0.004 0.012 b 0.33 0.51 0.013 0.020 c 0.23 0.32 0.009 0.013 d 12.6 13 0.496 0.512 e 7.4 7.6 0.291 0.299 e 1.27 0.050 h 10 10.65 0.394 0.419 h 0.25 0.75 0.010 0.030 l 0.4 1.27 0.016 0.050 k 0? (min.)8? (max.) outline and mechanical data tea2025b - tea2025d 7/9
dip16 dim. mm inch min. typ. max. min. typ. max. a1 0.51 0.020 b 0.77 1.65 0.030 0.065 b 0.5 0.020 b1 0.25 0.010 d 20 0.787 e 8.5 0.335 e 2.54 0.100 e3 17.78 0.700 f 7.1 0.280 i 5.1 0.201 l 3.3 0.130 z 1.27 0.050 outline and mechanical data tea2025b - tea2025d 8/9
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