mitsumi ic for multifunction telephones lag640 ic for multifunction telephones monolithic ic lag640 this ic was developed for use in multifunctional telephones with security features; it has the following functions. features 1. incorporates efficient switching regulator with broad input voltage range v out 5v0.25 i l 250ma (13~45v) v in 15~45v 2. internal data transmission/reception circuits data can be superposed on the power supply line for transmission. can be switched between two different input modes 3. internal system reset circuit 5v line abnormal voltage detection circuit watchdog timer reset circuit 4. internal speaker amp 260 mw typ. at 8 load mute pin 5. internal beep sound generator circuit with pin to vary audio volume (also used to turn beep sound on and off) package sdip-30a (LAG640D) absolute maximum ratings (ta=25 c ) item symbol ratings units operating temperature t opr - 20~+70 c storage temperature t stg - 40~+125 c power supply current v cc max. 46 v allowable loss pd 750 mw outline
mitsumi ic for multifunction telephones lag640 electrical characteristics (except where noted otherwise, ta=25c, v cc =30v) item symbol measurement measurement conditions min. typ. max. units circuit swr unit output voltage (5v) v o 11 v cc =15~45v 4.75 5.00 5.25 v i l =0~250ma output voltage (5v) v o 21 v cc =13~45v 4.70 5.00 5.25 v i l =0~200ma output ripple voltage vr 1 i l =250ma 50 mv p - p reactive current i cc q1 i l =0ma 610ma amp & transmission unit swr oscillation frequency f osc 180khz output current on short-circuit i os 1r s =0.2 70 110 150 ma power supply voltage detection unit detection voltage v s 2 * 4.30 4.50 4.80 v detection drop voltage v s 2v s =vo - v s 0.2 v output current while on ir on 2 vo=4v 10 20 ma leakage output current while off ir off 2 vo=5.25v 1 a note: the asterisk ( * ) indicates that the power supply voltage detection unit characteristics are standards in the transient power on/off states. however, for convenience the detection voltage is taken to be the value of v 0 when v 0 in measurement circuit 2 is varied and the pin 6 output state is switched from off to on.
mitsumi ic for multifunction telephones lag640 electrical characteristics (except where noted otherwise, ta=25c, v cc =30v faudio=1khz) item symbol measurement measurement conditions min. typ. max. units circuit power amp unit amp gain g v 1 voa=0.775vrms 37 40 43 db maximum distortion-free output p o max. 1 thd=10% 150 260 mv distortion thd 1 p o =100mw 5 % attenuation at 100 hz gf1/gf0 1 f o =1khz, fl=100hz - 14 db voa=0.775vrms attenuation at 10 hz gf2/gf0 1 f2=10 khz, above conditions - 8db input imp 1 r in 1 3 mute off 10 15 k input imp 2 r in 2 3 mute on 2.5 3.5 k mute on residual noise 1 vno1 1 audio in 20mvrms 0.5 mvrms i l =10 70ma 1.5khz transmission unit on ft=1khz mute off residual noise 2 vno2 1 audio off 1.2 mvrms i l =10 70ma 1.5khz transmission unit on ft=1khz beep sound generator unit beep sound frequency fb 1 0.85 1.0 1.15 khz beep off switching point ibsw 1 pin 9 input current 20 35 48 a beep sound output 1 vob1 1 pin 9 connected to gnd through 4.7k 1.0 1.4 1.8 vrms amp output voltage beep sound output 2 vob2 1 pin 9 connected to gnd through 47k 0.11 0.16 0.22 vrms watchdog timer unit timer time tt 1 cf. watchdog timer 2.4 3.0 3.6 s waveform diagram cf. watchdog timer 0.45 1.1 output pulse width t pw 1 waveform diagram ms t=beep sound period (1/2t) (1t) output voltage while on vw on 1 0.5 v leakage output current while off iw off 11a timer-clearing pulse width tcl 1 5 s transmission circuit unit transmission output voltage (1) vto1 2 r l -110 , peak value 5.1 5.8 6.6 vp-p across pins l3 - l4 transmission output voltage (2) vto2 2 r l -1 , peak value 5.5 6.2 7.0 vp-p across pins l3 - l4 l3 pin voltage vl3 2 no signal 4.0 4.4 4.8 v l4 pin voltage vl4 2 no signal 0.5 0.7 0.9 v reception sensitivity vrs 2 0.8 1.0 1.2 vp-p input imp r in 3 4 both pins 7and 8 14 20 26 k transmission delay time td1 2 cf. transmit/receive 0.4 s waveform diagrams transmission delay time td2 2 cf. transmit/receive 0.4 s waveform diagrams transmission delay time td3 2 cf. transmit/receive 0.8 s waveform diagrams transmission delay time td4 2 cf. transmit/receive 0.8 s waveform diagrams reception output h voltage vroh 2 r l =10k 4.5 v reception output l voltage vrol 2 r l =1.5k 0.5 v general logic unit characteristics h level input voltage vih 3 2.4 v l level input voltage vil 3 0.8 v h level input current iih 3 v in =2.4v 10 a l level input current iil 3 v in =0.4v - 300 a
mitsumi ic for multifunction telephones lag640 watchdog timer waveform diagrams tt tpw timer clear (22pin) (21pin) interrupt output (20pin) note: pulses to clear the timer must have a width of 5 s or more. transmit/receive waveform 1. when pulling pin 25 up to v dd (+5v) sg (24pin) sd (dtc) 23pin l3 (27pin) l4 (26pin) 2. when shorting pin 25 to gnd sg (24pin) sd (dtc) 23pin l3 (27pin) l4 (26pin) td2 td1 td4 td3 sg l3 l4 reception data out
mitsumi ic for multifunction telephones lag640 measuring circuit measurement circuit 1 measurement circuit 2
mitsumi ic for multifunction telephones lag640 measurement circuit 3 measurement circuit 4
mitsumi ic for multifunction telephones lag640 switch operation (measurement circuit 1) measurement item sw1 sw2 sw3 sw4 other conditions vo1, vo2 1 vr 1 no spike noise i cc q 1 a1 only i os 1 a2 only g v , p o max., thd 1 thd measured after passing through gf1/gf0, gf2/gf0 400hz-15khz bpf vno1 2 using 400hz-15khz bpf vno2 2 using 400hz-15khz bpf fb, ibsw, vob1, vob2 1 - 1 tt, t pw , vwon, tcl cf. watchdog timer waveform diagram i woff - 1 switch operation (measurement circuit 2) measurement sw1 sw2 sw3 sw4 sw5 sw6 sw7 vto1 11 - peak value across pins l3, l4 22 - peak value across pins l3, l4 vto2 11 - peak value across pins l3, l4 22 - peak value across pins l3, l4 vl3 231 vl4 232 vrs 22 - measured with rt adjusted td1~td4 22 - cf. transmit/receive waveform diagrams vroh, vrol 22 -
mitsumi ic for multifunction telephones lag640 block diagram and application circuits 1. the watchdog timer time is determined by the values of rw and cw. tt . = . rw cw where rw is 56k to 560k cw is between 0.01f and 10f 2. the beep sound frequency is determined by rb and cb. fb . = . 1/rb cb where rb is 56k to 330k cb is between 4700pf and 22,000pf. 3. the beep sound volume can be varied through the resistance connected to pin 10. 4.7k the voltage is approx. 4v p-p , and at 47k it is about 0.4v p-p . 4. in overload protection operation the voltage across pins 1 to 30 is tested, with a limit of 100 20mv. on load shorting, the test voltage is dropped to about 1/4 to conserve power.
mitsumi ic for multifunction telephones lag640 even when a 5v external voltage can be supplied, an addition voltage of 13 to 45v must be applied to pins 3 and 4 in order to obtain an internal biased power supply of 7.4v. in order to prevent abnormal oscillation of the amplification circuit, a 5 v power supply must be connected to pin 15 to halt amplification functions. (swr circuit not used) additional application example 1 (speaker amp not used) additional application example 2
mitsumi ic for multifunction telephones lag640 notes on use 1. protection from high-frequency noise in consideration of applications in which telephone sets are connected over long distances, this ic is designed for high withstand and static breakdown voltages at pins 3 and 4, which are in danger of being exposed to electrostatic charge and high-frequency noise. pins 3 and 4 dc withstand voltage 46v or higher static breakdown voltage 1000v or higher (human body buildup method, 200pf, 0 ) other pins dc withstand voltage 15v or higher static breakdown voltage 300v or higher (human body buildup method, 200pf, 0 ) however, the ic may be damaged by adverse mounting or use conditions, and so it is recommended that a surge suppressor be inserted between pin 4 and gnd. 2. protection from surge currents a diode for capacitor charging is connected between data transmission output pins 26 and 27 as shown below; the surge current ratings shown below should not be exceeded. if these ratings are to be exceeded, it is recommended that a resistance r for surge current limiting or a diode dt for absorption be inserted. internal diode maximum ratings io 100ma if (peak) 500ma if (surge) 700ma
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