TDA7240A december 1998 20w bridge amplifier for car radio . compact heptawatt package . few external components . output protected against short circuits to ground and across load . dump transient . thermal shutdown . loudspeaker protection . high current capability . low distortion/low noise description heptawatt h heptawatt v ordering numbers: TDA7240Ah TDA7240Av the TDA7240A is a 20w bridge audio amplifier ic designed specially for car radio applications. thanks to the low external part count and compact heptawatt 7-pin power package the TDA7240A occupies little space on the printed circuit board. reliable operation is guaranteed by a comprehen- sive array of on-chip protection features. these in- clude protection against ac and dc output short circuits (to ground and across the load), load dump transients, and junction overtemperature. additio- nally, the TDA7240A protects the loudspeaker when one output is short-circuited to ground. figure 1: test and application circuit ? 1/8
absolute maximum ratings symbol parameter value unit v s operating supply voltage 18 v v s dc supply voltage 28 v v s peak supply voltage (for 50ms) 40 v i o (*) peak output current (non repetitive t = 0.1ms) 4.5 a i o (*) peak output current (repetitive f 3 10hz) 3.5 a p tot power dissipation at tcase = 85 c 16 w t stg , t j storage and junction temperature C40 to 150 c (*) internally limited pin connection (top view) thermal data symbol parameter value unit r th j-case thermal resistance junction-case max. 4 v TDA7240A 2/8
electrical characteristics (refer to the circuit of fig. 1, t amb = 25 c, r th (heatsink) = 4 c/w, v s = 14.4v) symbol parameter test conditions min. typ. max. unit v s supply voltage 18 v v os output offset voltage 150 mv i d total quiescent current r l = 4 w 65 120 ma p o output power f = 1khz; d = 10% r l = 4 w r l = 8 w 18 10 20 12 w w d distortion r l = 4 w f = 1khz p o = 50mw to 12w 0.1 0.5 % r l = 8 w f = 1khz p o = 50mw to 12w 0.05 0.5 % gv voltage gain f = 1khz 39.5 40 40.5 db svr supply voltage rejection f = 100hz r g = 10k w 35 40 db e n total input noise r g = 10k w (*) (**) 2 310 m v m v h efficiency r l = 4 w f = 1khz 65 % i sb stand-by current 200 m a r i input resistance f = 1khz 70 k w v i input sensitivity f = 1khz; p o = 2w; r l = 4 w 28 mv f l low frequency roll off (C3db) po = 15w; r l = 4 w 30 hz f h high frequency roll off (C3db) po = 15w; rl = 4 w 25 khz a s stand-by attenuation v o = 2vrms 70 90 db v th (pin2) stand-by threshold 1 v (*) b= curve a (**) b = 22hz to 22 khz figure 2 : p.c. board and components layout of the circuit of fig. 1.(1:1scale) TDA7240A 3/8
application suggestion the recommended values of the components are those shown on application circuit of fig. 1. different values can be used, the following table can help the designer. component recommended value purpose larger than smaller than r1, r2 2.2 w frequency stability danger of high frequency oscillation c1 1 m f input dc decoupling higher turn on and stand-by delay higher turn on pop. higher low frequency cutoff c2 22 m f ripple rejection increase of svr increase of the turn on delay degradation of svr c3 22 m f feedback low frequency cutoff higher low frequency cutoff c6, c7 0.22 m f frequency stability danger of oscillation c4 220 m f supply filter danger of oscillation c5 0.1 m f supply bypass danger of oscillation figure 4 : distortion vs. output power. figure 3 : output power vs. supply voltage. figure 6 : distortion vs. output power. figure 5 : output power vs. supply voltage. TDA7240A 4/8
figure 8 : supply voltage rejection vs. frequency. figure 7 : distortion vs. frequency. figure 10 : power dissipation and efficiency vs. output power. figure 9 : power dissipation and efficiency vs. output power. TDA7240A 5/8
heptawatt v dim. mm inch min. typ. max. min. typ. max. a 4.8 0.189 c 1.37 0.054 d 2.4 2.8 0.094 0.110 d1 1.2 1.35 0.047 0.053 e 0.35 0.55 0.014 0.022 e1 0.7 0.97 0.028 0.038 f 0.6 0.8 0.024 0.031 f1 0.9 0.035 g 2.34 2.54 2.74 0.095 0.100 0.105 g1 4.88 5.08 5.28 0.193 0.200 0.205 g2 7.42 7.62 7.82 0.295 0.300 0.307 h2 10.4 0.409 h3 10.05 10.4 0.396 0.409 l 16.7 16.9 17.1 0.657 0.668 0.673 l1 14.92 0.587 l2 21.24 21.54 21.84 0.386 0.848 0.860 l3 22.27 22.52 22.77 0.877 0.891 0.896 l4 1.29 0.051 l5 2.6 2.8 3 0.102 0.110 0.118 l6 15.1 15.5 15.8 0.594 0.610 0.622 l7 6 6.35 6.6 0.236 0.250 0.260 l9 0.2 0.008 m 2.55 2.8 3.05 0.100 0.110 0.120 m1 4.83 5.08 5.33 0.190 0.200 0.210 v4 40? (typ.) dia 3.65 3.85 0.144 0.152 a l l1 c d1 l5 l2 l3 d e m1 m h3 dia. l7 l6 f1 h2 f gg1g2 e1 f e l9 v4 l4 h2 vv heptamec h1 outline and mechanical data TDA7240A 6/8
heptawatt h dim. mm inch min. typ. max. min. typ. max. a 4.8 0.189 c 1.37 0.054 d 2.4 2.8 0.094 0.110 d1 1.2 1.35 0.047 0.053 e 0.35 0.55 0.014 0.022 f 0.6 0.8 0.024 0.031 f1 0.9 0.035 g 2.41 2.54 2.67 0.095 0.100 0.105 g1 4.91 5.08 5.21 0.193 0.200 0.205 g2 7.49 7.62 7.8 0.295 0.300 0.307 h2 10.4 0.409 h3 10.05 10.4 0.396 0.409 l 14.2 0.559 l1 4.4 0.173 l2 15.8 0.622 l3 5.1 0.201 l5 2.6 3 0.102 0.118 l6 15.1 15.8 0.594 0.622 l7 6 6.6 0.236 0.260 l9 4.44 0.175 dia 3.65 3.85 0.144 0.152 outline and mechanical data TDA7240A 7/8
information furnished is believed to be accurate and reliable. however, stmicroelectronics assumes no responsibility for the co nse- quences of use of such information nor for any infringement of patents or other rights of third parties which may result from i ts use. no license is granted by implication or otherwise under any patent or patent rights of stmicroelectronics. specification mentioned in this publication are subject to change without notice. this publication supersedes and replaces all information previously supplied. stmi- croelectronics products are not authorized for use as critical components in life support devices or systems without express wr itten approval of stmicroelectronics. the st logo is a registered trademark of stmicroelectronics heptawatt ? is a trademark of sgs-thomson microelectronics ? 1998 stmicroelectronics C printed in italy C all rights reserved stmicroelectronics group of companies australia - brazil - canada - china - france - germany - italy - japan - korea - malaysia - malta - mexico - morocco - the neth erlands - singapore - spain - sweden - switzerland - taiwan - thailand - united kingdom - u.s.a. http://www.st.com TDA7240A 8/8
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