ICM7111 speech and ringer ic rev. 2.1 icmic reserves the right to change the spe cifications without prior notice 1 features ? includes speech and ringer circuit in a single chip ? operating range from 15 to 100ma ? dtmf interface with adjustable gain ? mute input for pulse of dtmf dialing ? voltage regulator output ? ring frequency discrimination ? ring melody generator overview ICM7111 is a low cost cmos speech and ringer integrated circuit (ic) that perform all the necessary speech and line interface functions for telephone sets. . typical application circuit figure 1 : typical application circuit
ICM7111 speech and ringer ic rev. 2.1 icmic reserves the right to change the spe cifications without prior notice 2 package 24-lead soic 24 lead so ic agnd 1 24 stb vdd 2 23 rxi vddi 3 22 rxo gnd 4 21 ci txo 5 20 m1 vl 6 19 m2 llc 7 18 muteb hs 8 17 dtmf osc1 9 16 dtmf o osc2 10 15 vupb rgd 11 14 vclkb mo 12 13 n/c top view
ICM7111 speech and ringer ic rev. 2.1 icmic reserves the right to change the spe cifications without prior notice 3 pin description pin no symbol description 1 agnd analog ground analog ground reference. 2 vdd regulated supply voltage can be used to power up external microcontroller. 3 vddi supply input voltage power for the chip is extracted from this pin. 4 gnd ground 5 txo transmit output transmit output to be connected to external power t ransistor for regulating vddi (dc) and for the modulation of line voltage. 6 vl line voltage 7 llc line loss compensation 0v = no llc; agnd=low llc; vdd=high llc. 8 hs hook switch input must be high to activate the speech network. must be low when line is disconnected to properly r eset the speech network. 9 osc1 oscillator input 3.58mhz ceramic resonator input. 10 osc2 oscillator output 11 rgd ring detection input input for ring frequency detection. 12 mo melody output melody pulse output for tone ringer. open drain nmo s. 13 n/c no connection 14 vclkb volume control clock input if vupb = 0; vclkb pulse increases the volume in 3 steps to maximum. if vupb = 1; vclkb pulse decreases the volume in 4 steps to minimum. has weak internal pull-up. should be connected to v dd if not used. 15 vupb volume up/down determines whether a pulse on vclkb would increase or decrease the volume. has weak internal pull-up. should be connec ted to vdd if not used. 16 dtmf dtmf input dtmf input (or any analog input signal). use a seri es resistor (for input resistance) and a series capacitor (for decoupling) to the dtmf pin. see dtmfo pin. 17 dtmfo dtmf feedback output dtmf feedback output. connecting a resistor between dtmf and dtmfo pins provides feedback. referring to figure 1, dtmf o = (r23/r24) x dtmfin. 18 muteb mute transmitter when muteb is low, the m1/m2 mic input is blocked, and the input from dtmf pin is transmitted. meant for dtmf dialing. 19 20 m2 m1 microphone inputs input for electret microphone. 21 ci complex impedance input connecting capacitor to this pin results in complex ac impedance. 22 rxo receive output these outputs drive a dynamic earpiece. 23 rxi receive input input for received signal. 24 stb side tone balance input side tone cancellation input.
ICM7111 speech and ringer ic rev. 2.1 icmic reserves the right to change the spe cifications without prior notice 4 functional description system startup ICM7111 generates internal power-on-reset when vdd reaches around 1.5v. power-on- reset appropriately initiates the system to a known initial state. ICM7111 stays in shutdown mode so long as hs pin stays low. however, the ringer circuitry is activated in this mode to monitor the incoming ringing signal. oscillator all the timing of ICM7111 is based on a clock frequency of 3.58 mhz. a crystal oscillator or ceramic resonator of this frequency should be connected to oscilator pins of ICM7111. care has to be taken in selecting this components since in practise minor deviations from the nominal frequency may occur due to the characteristics of the oscillator used. it is recommended to connect a small value capcitors ( 47pf) in parallel with the oscillator to ensure proper start-up and operation at the nominal frequency. tone ringer the tone ringer of ICM7111 consists of ring detection circuit and melody generator circuit. ring detection circuit ring detection circuit will assures the signal that present on rgd pin input is valid. the signal is considered as a valid signal if the signal has frequencies between 13hz and 70hz. melody generator once the valid ring signal is detected on the ring detection (rgd) pin and is present for about 75 ms continously, the melody generator will be actived, the ring signal will be monitored continously and the melody generator will be immediately turn on or off according to the momentary presence of a valid or unvalid ring signal respectively until next power on reset or off-hook. the melody generator of ICM7111 creates 2 frequencies of 1250hz and 1600hz. speech network the speech network of ICM7111 consists of a transmitter and a receiver path, side tone cancellation and line loss compensation. the speech network is activated as soon as the phone goes off-hook (i.e. when hs pin goes high). transmit for 600 ohm termination, the typical transmit gain from microphone input to the line voltage is 35db. receive typical receive path gain is 3db for 600 ohm termination. side tone cancellation as shown in the typical application circuit, side tone cancellation can be achieved best by balancing the whitestone bridge of r11, r12, and r13 + r14//c6 (refer to figure 1). line loss compensation llc input level is scanned as the phone goes off-hook (i.e. as hs pin goes high). at the same time, the loop current level is sensed and determined. if llc=0, no compensation scheme is in effect. if llc=agnd, ?low? compensation scheme is in effect. transmit and receive gains are reduced by as much as 6db when the loop current exceeds 50ma. if llc=vdd, ?high? compensation scheme is in effect. transmit and receive gains are reduced by as much as 6db when the loop current exceeds 75ma. dtmf/analog signal transmission ICM7111 can transmit dtmf (or any analog signal) through dtmf pin. referring to figure 1, the typical transmit gain is as follow: dtmfo = (r23/r24) x dtmfin txo = 4 x dtmfo muteb must be low for the input thru dtmf pin to be transmitted to txo.
ICM7111 speech and ringer ic rev. 2.1 icmic reserves the right to change the spe cifications without prior notice 5 absolute maximum rating symbol parameter value unit vddi supply line voltage -0.3 to 7.0 v v in_ digital input voltage -0.3 to 7.0 v t stg storage temperature -55 to +150 o c t sol soldering temperature 300 o c note 1: stress greater than those listed under abso lute maximum ratings may cause permanent damage to the device. this is a stress rating only and functional operati on of the device at these or any other conditions a bove those indicated in the operational sections of this specification is not i mplied. exposure to absolute maximum rating conditi ons for extended periods may affect reliability. operating range range ambient temperature commercial -25 o c to 70 o c electrical characteristics (i line = 15ma unless otherwise specified) symbol parameter test conditions min typ max unit vddi regulated line voltage (dc) i line : 13ma to 100ma 4.0 v vdd regulated supply i line : 13ma to 100ma 3.7 v agnd regulated agnd reference i line : 13ma to 100ma 1.5 v i dd operating current speech mode ring mode v dd = 2.5v 3 0.3 ma ma i ol output current sink txo, mo v ol = 0.4v 1.5 ma vil input voltage low hs, rgd t a =25 o c vss 0.3 vdd vih input voltage high rgd t a =25 o c 0.7 1 vdd hs t a =25 o c 2.7 vdd v transmit (tx) g tx_m1m2 transmit gain (m1/m2) muteb = high 35 db g tx_dtmf transmit gain (dtmfo to txo) muteb = low 12 db thd distortion v il < 0.5 v rms 2 % z in m1m2 input impedance (m1/m2) 20 k g mute mute attenuation (m1/m2) muteb = low 60 db v in m1m2 input voltage range (m1/m2) differential single ended +/- 1 +/- 0.5 v pp v pp receive (rx) g rx receive gain (vl to rxo) 3 db thd distortion v rxi < 0.5 v rms 2 % z in_rxi input impedance (rxi) 8 k z in_stb input impedance (stb) 80 k v in rxi input voltage range +/- 2 v peak
ICM7111 speech and ringer ic rev. 2.1 icmic reserves the right to change the spe cifications without prior notice 6 output driver (bjt) v in max input voltage range +/- 2 v peak v tx dynamic range +/- 2 v peak rl return loss z rl = 1000 18 db side tone (st) g st side tone cancellation 26 db v in stb input voltage range +/- 2 v peak hs input t hs-l low to high debounce going off-hook 15 ms tone ringer v mo melody output pdm t md melody delay 10 ms f1 frequency 1 1250 hz f2 frequency 2 1600 hz t dt detection time ring freq = 20hz 50 80 ms f min min. detection frequency 13 hz f max max. detection frequency 70 hz
ICM7111 speech and ringer ic rev. 2.1 icmic reserves the right to change the spe cifications without prior notice 8 package information 24-lead soic (unit: inches)
ICM7111 speech and ringer ic rev. 2.1 icmic reserves the right to change the spe cifications without prior notice 9
ICM7111 speech and ringer ic rev. 2.1 icmic reserves the right to change the spe cifications without prior notice 10 disclaimer the information contained herein is current as of t he date of publication; however, delivery of this document shall not under any circumstances create a ny implication that the information contained herein is correct as of any time subsequent to such date. icmic reserves the right to make changes without notification, even if such changes would re nder information contained herein inaccurate or incomplete. icmic makes no representation or warran ty that any circuit designed by reference to the information contained herein, will function without errors and as intended by the designer.
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