september 2003 1/7 tea6420 bus-controlled audio matrix switch n 5 stereo inputs n 4 stereo ouputs n gain control 0/2/4/6db/mute for each output n cascadable (2 different addresses) n serial bus controlled n very low noise n very low distorsion description the tea6420 switches 5 stereo audio inputs on 4stereo outputs. all the switching possibilities are changed through the i 2 c bus. figure 1. pin connections so28 (plastic micropackage) order code: tea6420d shrink dip 24 (plastic package) order code: tea6420 6420-01.eps - 6420-02.eps 1 2 3 4 5 6 7 8 9 10 20 19 18 17 16 15 14 13 24 23 22 21 11 12 gnd capacitance l1 l2 l3 l4 l5 lout1 rout1 lout2 rout2 sda scl addr r1 r2 r3 r4 r5 rout4 lout4 rout3 lout3 v s gnd capacitance l1 l2 l3 l4 l5 lout1 rout1 lout2 rout2 sda scl addr r1 r2 r3 r4 r5 rout4 lout4 rout3 lout3 v s 1 2 3 4 5 6 7 8 9 10 20 19 18 17 16 15 24 23 22 21 11 12 25 13 14 28 27 26 nc nc nc nc 1
tea6420 2/7 figure 2. block diagram 6420-03.eps supply bus decoder right outputs left outputs sda scl addr right inputs gain = 0/2/4/6db gain = 0/2/4/6db v s c gnd left inputs t e a 6 4 2 0 1
tea6420 3/7 absolute maximum ratings thermal data electrical characteristics t a = 25 oc , v s = 10v, r l = 10k w , r g = 600 w , f = 1khz (unless otherwise specified) symbol parameter value unit v cc supply voltage (pin 9) 12 v t oper operating ambient temperature range 0 to +70 o c t stg storage temperature range -20 to +150 o c symbol parameter+ value unit r th (j-a) junction-ambient thermal resistance sdip24 so28 75 75 o c/w symbol parameter test conditions min. typ. max. unit supply v s supply voltage 8 9 10.2 v i s supply current 58ma svr ripple rejection v in = 500mv rms , bw = 20 - 20khz 70 80 db matrix v in input dc level 4.5 5 5.5 v r i input resistance 30 50 100 k w c s channel separation v in = 2v rms gain = 0db f = 1khz gain = 6db 80 70 90 82 db db output buffer v out output dc level 4.5 5 5.5 v r out output resistance 70 200 w e ni input noise bw = 20 - 20khz, flat 3 v s/n signal to noise ratio v in = v out = 1v rms 110 db g min min. gain -1 0 + 1 db g max max. gain 56 7db d distortion v in = v out = 1v rms 0.01 0.05 % v cl clipping level d = 0.3% 2 2.5 v rms r l output load resistance 2k w bus input v il input low voltage 1.5 v v in input high voltage 3v i i input current - 10 10 a v o output voltage i o = 3ma ; sda acknowledge pin 0.4 v r pu addr pullup resistor note 40 50 k w 1
tea6420 4/7 software specification 1. chip address 2. data bytes x = don't care - msb is transmitted first example : 010xx100 connects outputs 3 with input 5 at a gain of 4db the following are selected after power-on reset : input 5 selected for all outputs ; gain = 0db. address hex addr 1001 1000 98 0 1001 1010 9a 1 output select x0 0 1 1 0 1 0 1 g 1 g 0 i 2 i 1 i 0 output 1 output 2 output 3 output 4 input select xq 1 q0 g 1 g 0 0 0 0 0 1 1 0 0 1 1 0 0 0 1 0 1 0 1 input 1 input 2 input 3 input 4 input 5 mute gain select xq 1 q0 0 0 1 1 0 1 0 1 i 2 i 1 i 0 gain = 6 db gain = 4 db gain = 2 db gain = 0 db 1
tea6420 5/7 typical application figure 3. 6420-08.04 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 m 22 f 100nf c 1 c 2 c 3 c 4 c 5 c 11 c 12 c 13 c 14 ch2 output l r l r ch1 output left inputs c 15 c 16 c c 17 18 c 10 c c 9 8 c c 7 6 sw r l ch3 output r l ch4 output right inputs bus inputs scl sda t e a 6 4 2 0 +9v 1
tea6420 6/7 package mechanical data 24 pins - plastic dip figure 4. 24-pin package 28 pins - plastic so figure 5. 28-pin package stand-off a1 b e b1 d 13 12 24 1 f la e1 a2 c e1 e e2 gage plane .015 0,38 e2 e3 e sdip24 1
tea6420 7/7 information furnished is believed to be accurate and reliable. however, stmicroelectronics assumes no responsibility for the co nsequences of use of such information nor for any infringement of patents or other rights of third parties which may result from its use. no license is granted by implication or otherwise under any patent or patent rights of stmicroelectronics. specifications mentioned in this publicati on are subject to change without notice. this publication supersedes and replaces all information previously supplied. stmicroelectronics prod ucts are not authorized for use as critical components in life support devices or systems without the express written approval of stmicroele ctronics. the st logo is a registered trademark of stmicroelectronics ? 2003 stmicroelectronics - all rights reserved. purchase of i 2 c components by stmicroelectronics conveys a license under the philips i 2 c patent. rights to use these components in an i 2 c system is granted provided that the system conforms to the i 2 c standard specification as defined by philips. stmicroelectronics group of companies australia - brazil - china - finland - france - germany - hong kong - india - italy - japan - malaysia - malta - morocco - sin gapore - spain sweden - switzerland - united kingdom - u.s.a. http://www.st.com
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