Semiconductor C January Features Monolithic Silicon COS/MOS ual-tone Multifrequency Tone Generator escription Mute rivers On-Chip evice Power can Either be Regulated C or Telephone Loop Current Use of an Inexpensive 3.MHz TV Crystal Provides High ccuracy and Stability for all Frequencies pplications For Use In ual-tone Telephone ialing Systems Ordering Information PRT NUMBER TEMP. RNGE ( o C) PCKGE PKG. NO. CE -0 to Ld PIP E.3 The C is a CMOS dual-tone multifrequency (TMF) tone generator for use in dual-tone telephone dialing systems. The device can easily be interfaced to a standard push-button telephone keyboard to provide enabling operation directly with the telephone lines. The C generates standard TMF sinusoidal dialing tones from an on-chip reference crystal oscillator. The reference oscillator uses an inexpensive 3.MHz color TV crystal to create highly stable and accurate tones. The sinusoidal tones are digitally synthesized by a stair-step approximation. One of four low-frequency band row tones and one of four high-frequency band column tones are selected by driving one of the four row inputs and one of the four column inputs low. Simultaneous selection of more than one row input and/ or more than one column input will inhibit tone generation, or generate a single-tone sinusoid. These operating modes are described in the functional truth table. Control logic is included to allow easy interface to standard K00-type telephones. Two CMOS outputs (T X, R X ) capable of driving external pnp receiver and transmitter muting transistors are provided. low input to the C pin inhibits tone generation, turns off the reference oscillator and causes T X and R X outputs to go to logic 0. uring tone generation mode, C = and T X, R X = logic. The row, column and C inputs are provided with pull-up resistors to allow the use of SPST switch matrixes. Pinout C (PIP) TOP VIEW TX C C 3 R C 3 R C3 R3 V SS R OSC 0 RX OSC C CUTION: These devices are sensitive to electrostatic discharge. Users should follow proper IC Handling Procedures. Copyright Harris Corporation - File Number.3
bsolute Maximum Ratings Supply Voltage ( - V SS ).......................-0. to V Input Voltage............................. -0.V to 0.V Power issipation, P T = -0 o C to 0 o C............................. 00mW T = 0 o C to o C...... erate Linearly at.mw/ o C to 00mW Thermal Information Maximum Junction Temperature....................... o C Maximum Junction Temperature (Plastic)................ 0 o C Maximum Storage Temperature Range.......... - o C to 0 o C Maximum Lead Temperature (Soldering 0s)............. 300 o C Operating Conditions Power issipation Per Output........................ 00mW Temperature Range.......................... -0 o C to o C CUTION: Stresses above those listed in bsolute Maximum Ratings may cause permanent damage to the device. This is a stress only rating and operation of the device at these or any other conditions above those indicated in the operational sections of this specification is not implied. T = - o C to 0 o C, ll Voltages Referenced to V SS = 0V PRMETER (V) MIN MX UNITS YNMIC C SUPPLY VOLTGE Tone Generation Mode with Valid Input (Note ). 0 V Non-Tone Generation (Note ). 0 V YNMIC OPERTING CURRENT Tone Generation Mode (Outputs Unloaded) 3. -. m.3-3 m No Keydown Mode 3. - 00 µ.3-00 µ Input Pull-Up Current 3-0 - 00 µ Input Low Voltage (V IL ) Maximum 3-0 - 0. V Input Low Voltage (V IH ) Minimum 3-0 - 0. V T = - o C to 0 o C STTIC TONE OUTPUTS (R L = Ω) PRMETER (V) V O (V) MIN MX UNITS V O ; ual-tone Output 3. -.3-30 00 mv RMS V O (C L ); Single-Tone Output, Column (Note 3) 3. -.3-300 - mv RMS V O (R L ); Single-Tone Output, Row (Note ) 3. -.3-0 - mv RMS istortion (Note ) 3. -.3 - - 0 % Rise and Fall Time (ual-tone Out) (Note ) 3. -.3 - - ms Pre-Emphasis (Note ) 3. -.3-3 db Output Frequency (Note ) 3. -.3 - (Nom. -%) (Nom. +%) Hz -
T = - o C to 0 o C (Continued) STTIC MUTE OUTPUT CURRENT PRMETER (V) V O (V) MIN MX UNITS Transmitter.. -0. - m I OH (Source) 0. -3. - m I OL (Sink) 0. - 0 µ Receiver.. -0. - m I OH (Source) 0. -3. - m I OL (Sink) 0. - 0 µ NOTES:. ll logic and counters functional.. Mute switches remain open. 3. Two or more row inputs low and one column input low.. Two or more column inputs low and one row input low.. istortion is defined as: The ratio of all extraneous frequency components generated in the voiceband 0.kHz to 3kHz, to the power of the dual-tone signal, measure across R L. ( V + V +... + V n ) istortion= ------------------------------------------------------------------, V L + V H where V, V.... V n are extraneous frequency components in the voiceband 0.kHz to 3kHz, V L is the low-band frequency tone, and V H is the high-band frequency tone.. Tone rise time is defined as the time for each of the TMF frequencies to attain 0% of full amplitude, measured from the time when a row and column signal are driven low.. Pre-emphasis is the ratio of the high-group level to the low-group level.. Refer to Figure for standard TMF frequencies.. Corresponds to normal dual-tone operation. 0. Corresponds to single-tone generation mode. -
COL COL COL 3 COL ROW 3 (.) ROW B 0 (.) ROW 3 C (.) ROW * 0 # (.0) 0 (.) 33 (33.) (.) 33 (.0) NOMINL OUTPUT FREQUENCY FIGURE. BELL N NOMINL OUTPUT FREQUENCIES (IN PRENTHESIS) FOR 3.MHz CRYSTL TMF GENERTOR FUNCTIONL TRUTH TBLE INPUTS OUTPUTS KEYBOR MOE NUMBER OF COLUMN INPUTS CTIVTE LOW NUMBER OF ROW INPUTS CTIVTE LOW C TONE OSC RUNNING R X T X X X X 0 None No 0 0 No Key epressed 0 0 None No 0 0 0 ual Tone R, C Yes,, 3, or 0 None No 0 0 Normal ialing One Key epressed (Note ) Same Row (Note 0) Same Column ifferent Rows and Columns ual Tone R, C B Yes, 3, or Single Row Tone R Yes, 3, or Single Column Tone C B Yes, 3, or, 3, or None Yes Where: X = on t Care R refers to Tone Output frequencies corresponding to Row, Row, Row 3, Row ; C B refers to Tone Output frequencies corresponding to Column, Column, Column 3, Column. =,, 3, B =,, 3, = B, or B -
Functional iagram C 3 COUNT CONT. COL. IVIER C- C3-3 C- C-3 3 C COL SENSE COL INH C3 C ROW IVIER R-0 R3- R-3 R- 3 C COUNT CONT. R ROW INH R 3 ROW SENSE ENBLE OP MP R3 R R X 0 OSC OSC OSC MUTE CONTROL T X V SS L d K.K.K K a G I K T X R X F RR B GN GN L R R C C V V C 3 L L g f /C R 3 R R L I T + R X T X OSC OSC VSS KEYP 3 * 0 # b L a c 3 C NETWORK FIGURE. INTERFCE WITH STNR K00 TELEPHONE NETWORK -0