KT8554B/ 7b 1 chip codecs introduction the KT8554B/7b are single-chip pcm encoders and decoders (pcm codecs) and pcm line filters. these devices provide all the functions required to interface a full-duplex voice telephone circuit with a time-division-multiplex (tdm) system. these devices are designed to perform the transmit encoding and receive decoding as well as the transmit and receive filter- ing functions in pcm system. they are intended to be used at the analog termination of a pcm line or trunk. these devices provide the bandpass filtering of the analog signals prior to encoding and after decoding. these combina- tion devices perform the encoding and decoding of voice and call progress tones as well as the signalling and supervision information. features complete codec and filtering system meets or exceeds at&t d3/d4 and ccitt specifications m - law : KT8554B, a-law : kt8557b on-chip auto zero, sample and hold, and precision voltage references low power dissipation : 60mw (operating) 3mw (standby) 5v operation ttl or cmos compatible automatic power down pin configuration fig. 1 device package operating temperature KT8554Bj kt8557bj 16-cerdip - 25 ~ 125 c kt8557bn KT8554Bn 16-dip-300a - 25 ~ 70 c KT8554Bd kt8557bd 16-sop-bd300 -sg - 25 ~ 70 c vf x i + vf x i - gs x ts x fs x s d x bclk x mclk x v bb gnda vf r o v cc fs r d r bclk r /clksel mclk r /pdn 1 2 3 4 5 6 7 8 16 15 14 13 12 11 10 9 kt8554 b /7 b ordering information 16-cerdip 16-dip- 300a 16-sop-bd300 -sg
KT8554B/ 7b 1 chip codecs pin description absolute maximum ratings ( ta = 25 o c) pin no symbol description 1 v bb v bb = - 5v 5%. 2 gnda analog ground. 3 vf r o analog output of the receive power amp. 4 v cc v cc = +5v 5%. 5 fs r receive frame sync pulse. 8khz pulse train. 6 d r pcm data input. 7 logic input which selects either 1.536mhz/1.544mhz or 2.048mhz for master clock in normal operation and bclk x is used for both tx and rx directions. alternately direct clock input available, very from 64khz to 2.048mhz. 8 when mclk r is connected continuously high, the device is powered down. normally connected continusously low, mclk x is selected for all dac timing. alternately direct 1.536mhz/1.544mhz or 2.048mhz clock input available. 9 mclk x must be1.536mhz/1.544mhz or 2.048mhz. may be vary from 64khz to 2.048mhz but bclk x is externally tied with mclk x in normal operation. 11 d x pcm data output. 12 fs x tx frame sync pulse. 8khz pulse train. 13 ts x changed from high to low during the encoder timeslot. open drain output. analog output of the tx input amplifier. used to set gain through external resistor. 15 vf x i - inverting input stage of the tx analog signal. 16 vf x i + non-inverting input stage of the tx analog signal. characteristic symbol value unit positive supply voltage v cc 7 v negative supply voltage v bb - 7 v voltage at any analog input or output v i (a) v cc + 0.3 to v bb - 0.3 v voltage at any digital input or output v l (d) v cc + 0.3 to gnda - 0.3 v operating temperature range ta - 25 to + 125 o c storage temperature range t stg - 65 to + 150 o c lead temperature (soldering, 10 secs) t lead 300 o c 10 bclk x bclk r / clksel mclk r / pdn gs x 14
KT8554B/ 7b 1 chip codecs electrical characteristics (unless otherwise noted, v cc = 5.0v 5%, v bb = - 5.0v 5%, gnda = 0v, ta = 0 o c to 70 o c ; typical characteristics specified at v cc = 5.0v, v bb = - 5.0v, ta = 25 o c ; all signals referenced to gnda). characteristic symbol test conditions min typ max unit power dissipation power-down current i cc (down) no load 0.5 1.5 ma power-down current i bb (down) no load 0.05 0.3 ma active current i cc (a) no load 6.0 9.0 ma active current i bb (a) no load 6.0 9.0 ma digital interface input low voltage v il 0.6 v input high voltage v ih 2.2 v input low current i il gnda v in v il , all digital inputs -10 10 m a input high current i ih v ih v in v cc -10 10 m a output low voltage v ol d x ,i l = 3.2ma sig r , i l = 1.0ma ts x , i l = 3.2ma,open drain 0.4 0.4 0.4 v v v d x , i h = -3.2ma sig r , i h = -1.0 ma 2.4 2.4 v v output current in high impedance state (tri-state) i o (hz) d x , gnda v o v cc -10 10 m a analog interface with receive filter output resistance r o pin vf r o 1 3 w load resistance r l vf r o = 2.5v 600 w load capacitance c l 500 pf output dc offset voltage v oo (rx) -200 200 mv analog interface with transmit input amplifier input leakage current i lkg -2.5v v +2.5v, vf x i + or vf x i - -200 200 na input resistance r i -2.5v v +2.5v, vf x i + or vf x i - 10 m w output resistance r o closed loop, unity gain 1 3 w load resistance r l gs x 10 k w load capacitance c l gs x 50 pf output dynamic range v od (tx) gs x , r l 10kw 2.8 v voltage gain g v vf x i + to gs x 5,000 v/v unity gain bandwidth bw 1 2 mhz offset voltage v io (tx) -20 20 mv common-mode voltage v cm (tx) cmrrxa > 60db -2.5 2.5 v common-mode rejection ratio cmrr dc test 60 db power supply rejection ratio psrr dc test 60 db output high voltage v oh
KT8554B/ 7b 1 chip codecs timing characteristics (unless otherwise noted , v cc = 5.0 5%, v bb = -5.0v 5%, gnda = 0v, ta = 0 o c to 70 o c; typical characteristics specified at v cc = 5.0v, v bb = -5.0v, ta = 25 o c; all signals referenced to gnda.) characteristic symbol test conditions min typ max unit frequency of master clocks f mck depends on the device used and the bclk r /clksel pin. mclk x and mclk r 1.536 1.544 2.048 mhz mhz mhz rise time of bit clock t r (bck) t pb = 488ns 50 ns fall time of bit clock t f (bck) t pb = 488ns 50 ns holding time from bit clock low to frame sync 0 ns holding time from bit clock high to frame sync 0 ns set-up time from frame sync to bit clock low 80 ns delay time from bclk x high to data valid 0 180 ns delay time to ts x low t d (tsxl) load = 150pf plus 2 lsttl loads 140 ns delay time from bclk x low to data output disabled 50 165 ns delay time to valid data from fs x or bclk x , whichever comes later t d (vd) c l = 0pf to 150pf 20 165 ns set-up time from d r valid to bclk r/x low 50 ns hold time from bclk r/x low to d r invalid 50 ns set-up time from fs x/r to bclk x/r low short frame sync pulse (1 or 2 bit clock periods long) (note1) 50 ns width of master clock high t w (mckh) mclk x and mclk r 160 ns width of master clock low t w (mckl) mclk x and mclk r 160 ns rise time of master clock t r (mck) mclk x and mclk r 50 ns fall time of master clock t f ( mck) mclk x and mclk r 50 ns set-up time from bclk x high (and fs x in long frame sync mode) to mclk x falling edge t su (bhmf) period of bit clock t ck 485 488 15,72 5 ns width of bit clock high t w (bckh) v ih = 2.2v 160 ns width of bit clock low t w (bckl) v il = 0.6v 160 ns t h (lfs) t h (hfs) t su (fbcl) t d (hdv) t d (ldd) t su (dr bl) t h (bl dr) t su (fbls) long frame only short frame only long frame only load = 150pf plus 2 lsttl loads first bit clock after the leading edge of fs x
KT8554B/ 7b 1 chip codecs timing characteristics (continued) note 1 : for short frame sync timing, fs x and fs r must go high while their respective bit clocks are high. timing diagram fig. 2. short frame sync timing characteristic symbol test conditions min typ max unit hold time from bclk x/r low to fs x/r low short frame sync pulse (1 or 2 bit clock periods long) (note 1) hold time from 3rd period of bit clock low to frame sync (fs x or fs r ) t h (3rd ) long frame sync pulse (from 3 to 8 bit clock periods long) 100 ns minimum width of the frame sync pulse (low level) t h (blfl) t wfl 64k bit/s operating mode 100 160 ns ns t d (ldd) t d (ts x l) t h (bldr) t h (bldr) t su (dr bl) t h (blfl) t h (hfs) t su (fbcl) t d (ldd) t d (hdv) t su (bhmf) t h (hfs) t su (fbls) t h (blfl) t w (mckh) t ck t w (mckl) t f (mck) t r (mck)
KT8554B/ 7b 1 chip codecs timing diagram (continued) fig. 3 long frame sync timing t w (bckh) t w (bckl) t r (mck) t w (mckl) t ck t h (bl dr) t h (bl dr) t su (dr bl) t h (3rd) t su (fbck) t h (hfs) t d (ldd) t d (hdv) t d (vd) t d (vd) t h (hfs) t rb t su (bhmf)
KT8554B/ 7b 1 chip codecs transmission characteristics (unless otherwise specified : ta = 0 o c to 70 o c, v cc = 5v 5%, v bb = -5v 5%, gnda = 0v, f = 1.02khz, v in = 0dbm0, transmit input amplifier connected for unity-gain non-inverting.) characteristic symbol test conditions min typ max unit amplitude respons receive gain, absolute g v (arx) ta = 25 o c, v cc = 5v, v bb = -5v input = digital code sequence for 0dbm0 signal at 1020hz -0.15 0.15 db receive gain, relative to g v (arx) g v (rrx) f = 0hz to 3000hz f = 3300hz f = 3400hz f = 4000hz -0.15 -0.35 -0.7 0.15 0.05 0 -14 db db db db absolute receive gain variation with temperature d g v (arx) / d t ta = 0 o c to 70 o c 0.1 db absolute receive gain variation with supply voltage d g v (arx) / d v v cc = 5v 5%, v bb = -5v 5% 0.05 db receive gain variations with level d g v (rxl) sinusoidal test method ; reference input pcm code corresponds to an ideally encoded -10dbm0 signal pcm level = -40dbm0 to +3dbm0 pcm level = -50dbm0 to -40dbm0 pcm level = -55dbm0 to -50dbm0 -0.2 -0.4 -1.2 0.2 0.4 1.2 db db db receive output drive level v o (rx) r l = 600 w -2.5 2.5 v absolute levels v al nominal 0dbm0 level is 4dbm (600 w ) 0dbm0 1.2276 v rms max overload level (3.17dbm0): KT8554B max overload level (3.14dbm0): kt8557b 2.501 v pk ta = 25 o c, v cc = 5v, v bb = -5v input at gs x = 0dbm0 at 1020hz -0.15 0.15 db transmit gain, relative to g v (atx) g v (rtx) f = 16hz f = 50hz f = 60hz f = 200hz f = 300hz - 3000hz f = 3300hz f = 3400hz f = 4000hz f = 4600hz and up, measure response from 0hz to 4000hz -1.8 -0.15 -0.35 -0.7 -40 -30 -26 -0.1 0.15 0.05 0 -14 -32 db db db db db db db db db absolute transmit gain variation with temperature d g v(atx) / d t ta = 0 o c to 70 o c 0.1 db absolute transmit gain variation with supply voltage d g v (atx) / d v v cc = 5v 5%, v bb = -5v 5% 0.05 db sinusoldal test method reference level = - 10dbm0 vf x i + = - 40dbm0 to + 3dbm0 vf x i + = - 50dbm0 to - 40dbm0 vf x i + = - 55dbm0 to - 50dbm0 - 0.2 - 0.4 - 1.2 0.2 0.4 1.2 db db db transmit gain, absolute g v (atx) max overload level v ol (max) d g v (txl) transmit gain variations with level
KT8554B/ 7b 1 chip codecs transmission characteristics (continued) characteristic symbol test conditions min typ max unit envelope delay distortion with frequency receive delay, absolute t d (arx) f = 1600hz 180 200 m s receive delay, relative to t d (arx) t d (rrx) f = 500hz - 1000hz f = 1000hz - 1600hz f = 1600hz - 2600hz f = 2600hz - 2800hz f = 2800hz - 3000hz -40 -30 -25 -20 70 100 145 90 125 175 m s m s m s m s m s transmit delay, absolute t d (atx) f = 1600hz 290 315 m s transmit delay, relative to t d (atx) t d (rtx) f = 500hz - 600hz f = 600hz - 800hz f = 800hz - 1000hz f = 1000hz - 1600hz f = 1600hz - 2600hz f = 2600hz - 2800hz f = 2800hz - 3000hz 195 120 50 20 55 80 130 220 145 75 40 75 105 155 m s m s m s m s m s m s m s noise receive noise, c message weighted n rxc pcm code equals alternating positive and negative zero, KT8554B 8 11 dbrnc0 receive noise, p message weighted n rxp pcm code equals, positive zero, kt8557b -82 -79 dbm0p transmit noise, c message weighted n txc KT8554B 12 15 dbrnc0 transmit noise, p message weighted n txp kt8557b 74 -67 dbm0p noise, single frequency n sf f = 0khz to 100khz, loop around measurement, vf x i + = 0v rms -53 dbm0 positive power supply rejection, transmit psrr (ptx) vf x i + = 0v rms , v cc = 5.0v dc + 100mv rms f = 0khz - 50khz 40 dbc negative power supply rejection, transmit psrr (ntx) vf x i + = 0v rms , v bb = -5.0v dc + 100mv rms f = 0khz - 50khz 40 dbc positive power supply rejection, receive psrr (prx) pcm code equals positive zero v cc = 5.0v dc + 100mv rms f = 0hz - 4000hz f = 4khz - 25khz f = 25khz - 50khz 40 40 36 dbc db db negative power supply rejection, receive psrr (nrx) pcm code equals positive zero v bb = 5.0v dc + 100mv rms f = 0hz - 4000hz f = 4khz - 25khz f = 25khz - 50khz 40 40 36 dbc db db
KT8554B/ 7b cmos integrated circuit transmission characteristics (continued) note 1. ct ( rx-tx) is measured with a - 40dbm0 activating signal applied at vf x i + encoding format at dx output characteristic symbol test conditions min typ max unit spurious out-of-band signals at the channel output sos loop around measurement, 0dbm0, 300hz - 3400hz input pcm applied to d r , measure individual image signals at vf r o 4600hz - 760hz 7600hz - 8400hz 8400hz - 100,000hz -32 -40 -32 db db db distortion signal to total distortion transmit or receive half-channel thd tx thd rx sinusoidal test method level = 3.0dbm0 = 0dbm0 to 30dbm0 = -40dbm0 xmt rcv = -55dbm0 xmt rcv 33 26 29 30 14 15 dbc dbc dbc dbc dbc dbc single frequency distortion, transmit -46 db single frequency distortion, receive -46 db intermodulation distortion thd imd loop around measurement, vf x i + = -4dbm0 to -21dbm0, two frequencies in the range 300hz - 3400hz -41 db crosstalk transmit to receive crosstalk, 0dbm0 transmit level f = 300hz - 3400hz d r = steady pcm code -90 -75 db receive to transmit crosstalk, 0dbm0 receive level -90 -70 (note1) db m -law KT8554B a-law kt8557b v in (at gs x ) = + full scale 1 0 0 0 0 0 0 0 1 0 1 0 1 0 1 0 1 1 1 1 1 1 1 1 0 1 1 1 1 1 1 1 1 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 v in (at gs x ) = - full scale 0 0 0 0 0 0 0 0 0 0 1 0 1 0 1 0 thd sf (tx) thd sf (rx) ct ( tx-rx) ct (rx-tx) f = 300hz - 3400hz, vf x i = 0v v in (at gs x ) = 0v
KT8554B/ 7b cmos integrated circuit application circuit fig. 4 note 1 : supposing desired line termination impedance r l = 600ohm it is 0dbm = 0.77459vrms note 2 : t x gain 20 log (r2/r1), r1 + r2 < 100kohm, or the correspondence of 1-chip codec 0dbm 0 = 4dbm. selection of master clock frequency vf x i + vf x i - gs x d x fs x s bclk x mclk x v bb gnd vf r o v cc fs r d r bclk r /clksel mclk r /pdn 1 2 3 4 5 6 7 8 16 15 14 11 12 10 9 kt8554 b /7 b r2 to slic from slic r1 r4 r3 pdn r6 fs x/r u-low only clock dr dx +5v -5v 0.1 m f 0.1 m f bclkr/clksel kt 8554 kt 8557 clocked 0 1 (or open) 1.536 / 1.544 mhz 2.048 mhz 1.536 / 1.544 mhz 2.048mhz 1.536 / 1.544 mhz 2.048mhz
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