unisonic technologies co., ltd tea2025d linear integrated circuit www.unisonic.com.tw 1 of 7 copyright ? 2014 unisonic technologies co., ltd qw-r107-017.c stereo audio amplifier ? description the utc tea2025d is a monolithic integrated circuit that intended for use as dual or bridge power audio amplifier portable radio cassette players. ? features * 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 external resistor. * soft clipping. * thermal protection. * 3v tea2025d linear integrated circuit unisonic technologies co., ltd 2 of 7 www.unisonic.com.tw qw-r107-017.c pin configuration 2 3 4 5 6 1 7 8 9 10 19 18 17 16 15 20 14 13 12 11 out2 boot2 gnd gnd gnd gnd feedback in 2(+) svr bridge gnd(sub) in 1(+) feedback gnd gnd gnd gnd boot1 out1 vcc block diagram
tea2025d linear integrated circuit unisonic technologies co., ltd 3 of 7 www.unisonic.com.tw qw-r107-017.c absolute maximum ratings parameter symbol ratings unit supply voltage v ss 15 v output peak current i o ( peak ) 1.5 a junction temperature t j 150 ? c storage temperature t stg 150 ? c note absolute maximum ratings are those values beyond which the device could be permanently damaged. absolute maximum ratings are stress ratings only an d functional device operat ion is not implied. thermal data parameter symbol ratings unit thermal resistance junction-case jc 15 ? c/w thermal resistance junction-ambient ja 65 ? c/w note: the ja is measured with 4 cm 2 copper area heatsink. electrical characteristics (ta=25 ? c, v cc =9v, stereo unless otherwise specified) parameter symbol test conditions min typ max unit supply voltage v ss 3 12 v quiescent current i q 35 50 ma quiescent output voltage v out 4.5 v voltage gain g v stereo 43 45 47 db bridge 49 51 53 db voltage gain difference ? g v ( diff ) 1 db input impedance r i 30 k ? output power (d=10%) r l =4 ? p out stereo 8 (per channel) v ss =3v 0.1 w r l =32 ? 0.02 r l =4 ? v ss =6v 0.7 1 r l =8 ? 0.6 r l =16 ? 0.25 r l =32 ? 0.13 r l =4 ? v ss =9v 1.7 2.3 r l =8 ? 1.3 r l =8 ? v ss =12v 2.4 r l =16 ? p out bridge v ss =3v 0.18 r l =32 ? 0.06 r l =4 ? v ss =6v 2.8 r l =8 ? 1.5 r l =8 ? v ss =9v 4.7 distortion stereo d v ss =9v; r l =4 ? 0.3 1.5 % bridge 0.5 % supply voltage rejection svr f=100hz,v r =0.5v,rg=0 40 46 db input noise voltage en (in) rg=0 1.5 3 mv rg=104 ? 3 6 mv cross-talk ct f=1khz, rg=10k ? 40 52 db
tea2025d linear integrated circuit unisonic technologies co., ltd 4 of 7 www.unisonic.com.tw qw-r107-017.c 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 f) 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 (100 f) avoids a reduction of the output signal also at low frequencies and low supply voltage. voltage gain adjust stereo mode the voltage gain is determined by on-chip resistors r1 an d r2 together with the external rfc1 series connected between pin 8(13) and ground. the frequency response is given approximated by: v out v in = r1 rf +r2+ 1 jwc1 with rf=0,c1=100 f, the gain results 46db with pole at f=32hz the purpose of rfi is to reduce the gain. it is recommended to not reduce it under 36db. bridge mode rf c1 r2 50 r1 10k 8(13) 2(19) figure 7 the bridge configuration is realized very easily thanks to an internal voltage divider which provides (at pin 1)the ch1 output signal after reduction. it is enough to connect pin8( inverting input of ch 2 )with a capacitor to pin 1 and to connect to ground the pin 9. 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 f,rf=0)means: gv=52db r1 10k figure 8 r1 10k r3 5k r4 50 r2 r2 out out in with first pole at f=32hz
tea2025d linear integrated circuit unisonic technologies co., ltd 5 of 7 www.unisonic.com.tw qw-r107-017.c application information(cont.) output capacitors . the low cut off frequency due to output capacitor depending on the load is given by: f l = 1 2 c out *r l with c out 470 f and r l =4 ohm it means f l =80hz. stability a good layout is recommended in order to avoid oscilla tions. in general, the designer must pay attention on the following points: -short wires of components and short connections. -no ground loops. -bypass of supply voltage with capacitors as nearest as possible to the supply i.c. pin. the low value (polyester) capacitors must have good temperat ure and frequency characteristics. -no sockets. 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 excessive junction te mperature: all that happens is that p out (and therefore p d ) and id are reduced. application suggestion the recommended values of the components are those shown on stereo application circuit of fig.2 different values can be used, the following table can help the designer. component recommended purpose larger than smaller than c1,c2 0.22 f input dc decoupling in case of slider contact noise of variable resistor c3 100 f ripple rejection degradation of svr, increase of thd at low frequency and low voltage c4,c5 100 f bootstrap c6,c7 470 f output dc decoupling increase of low frequency cut-off c8,c9 0.15 f frequency stability danger of oscillations c10,c11 100 f inverting input dc decoupling increase of low frequency cut-off
tea2025d linear integrated circuit unisonic technologies co., ltd 6 of 7 www.unisonic.com.tw qw-r107-017.c typical application circuit
tea2025d linear integrated circuit unisonic technologies co., ltd 7 of 7 www.unisonic.com.tw qw-r107-017.c typical characteristics utc assumes no responsib ility for equipment failures that result from using products at values that exceed, even momentarily, rated values (such as maximum ratings, operating condition ranges, or other parameters) listed in products specifications of any and all utc products described or contained herein. utc products are not designed for use in life support appliances, devices or systems where malfunction of these products can be reasonably expected to result in personal injury. reproduction in whole or in part is prohibited without the prior written consent of the copyright owner. the information presented in this document does not form part of any quotation or contract, is believed to be accurate and reliable and may be changed without notice.
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