TCM50

TCM5087 TI | Alldatasheet

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02650, NOVEMBER 1982—REVISED DECEMBER 1990 ©@ Low-Cost TV Color-Burst Crystal Sine-Wave N PACKAGE Input Produces Highly Accurate and Stable (Top view) Tones Vo fr Ure tone out © Device Powered Directly by Telephone or XMITTER SW(]2 _15[-] SINGLE-TONE ENABLE ‘Small Batteries cov1(js 1a[)ROW1 e cor2Qjs 13,)ROW 2 Keyboard or Electronic Input Capability cou3fls 2f}ROW 3 © Dual-Tone and Single-Tone Capability VssQe [Row 4 i osc inQ]7 —10f]MuTe ouT © Minimal Standby Power Requirement osc our fe eflcou 4 © Total Harmonic Distortion Meets EIA Standard RS-470 © PEP Processing Available © Wide Supply-Voltage Range © Minimal Parts Required NOT RECOMMENDED FOR NEW DESIGN © Single-Tone Production Can be Inhibited © Auxiliary Switching Outputs: One Bipolar Transistor and One CMOS Gate © Designed to be Interchangeable with Mostek MK5087 4. Caution. These devices have limited built-in gate protection. The leads should be shorted together or the device Mita Faced’ conductive foum during storage o handing to prevent electrostatic damage to the MOS gotes.

description

The TCMS087 tone encoder is a CMOS integrated circuit designed specifically to generate the dial tones used in dual-tone telephone dialing systems. It requires a sine-wave input normally supplied by a low-cost TV color-burst crystal at 3.579545 MHz to generate eight different audio sinusoidal frequencies. With this input the encoder generates dial tones that are very low in total harmonic distortion and comply with standard Dual-Tone Multi-Frequency (DTMF) specifications without any need for frequency adjustment. When generating a dual-tone signal, the encoder generates one column tone and one row tone and adds them for its output. The table below presents the frequencies produced by the tone encoder with the 3.579545-MHz TV-crystal signal input. Any deviation in this frequency will be reflected in the frequency output. The tolerance of the crystal is normally 0.02%. DTMF ENCODER ERROR TONE STANDARD | OUTPUT* | FROM STANDARD* (2) (tH) (%) Row? 697 701.8 70.62 Row 2 770 m4 +0.19 Row 3 852 857.2 +0.61 Row 4 941 935.1 -0.63 Column 1 1209 1215.9 +0.57 Column 2] 1336 1931.7 -0.32 Column 3 1477 1471.9 -0.35 Column 4 1633 1645 +0.73 “Using an input signal from a 3.679545-MHz crystal. LS PRODUCTION DATA decaments contain information Copyight © 1890, Texes instruments Incorporstad sara of pala data Produc cufora Te we ‘pacification per eras lastramest XAS stendard . Production does, tecestariy inaudefoting oa paramere INSTRUMENTS POST OFFICE BOX 655303 - DALLAS, TEXAS 78205 2-157

keyboard and electronic inputs The specific tone or tones generated are determined by inputs designated ROW 1 through ROW 4 and COLUMN 1 through COLUMN 4. The inputs are normally received from a 2-of-8 DTMF (DPST) keyboard, a Class A (SPST) keyboard, or an electronic circuit. Unlike dynamic or scanned inputs, the static inputs of the TCM5087 do not generate noise. See function table for input and output description. CLASS A KEYBOARD (SPST) 20f-8 DTMF KEYBOARD (DPST) | 4—— cOoLUMN COLUMN 4——4 4» row ‘Oren 4— row single-tone enable input This input inhibits the generation of single tones when taken low. All other chip functions remain unchanged. If the input is high or left open, single-tone operation is enabled. transmitter switch output This output is at high impedance when one or more of the column inputs are active and is high when all column inputs are inactive. The output is the emitter of a bipolar transistor whose collector is at VDD. ‘mute output The mute output is high when one or more column inputs are active and is low when all column inputs are inactive. functional block diagram ‘ose nw f° {8) osc our Yoo" a Yoo it TATE owt SE 2 OS Se BD: 000 pow Eg ce RR a we: iP, 7 a 1) [ : J yoo ONE ENABLE |) )> [ : | 116) TONE OUT vo0 ma, iH) an: CIRO K CI en 12). xMiTTER SW COLUMN 1 i=zseey Seer pC > oS (So Slee OS 6 |e o COLUMN 3“) $$ e2632) $2 wore our Vss i ss ———— TEXAS ap INSTRUMENTS 2-158 POST OFFICE 80x 685903 » DALLAS, TEXAS 75265

A TONE ENCODER FUNCTION TABLE INPUT TRANSMITTER SWITCH comanationst [PIN 15 OPEN | PIN 18 AT Ves | 0 columns. a ee Row and column | Rew end column 1 column [ica | come fee Column 1 column T row a ee 2 or more rows ee fs, fee fe fe [| O rows lomme |e | 2 foe fT | Row inputs will be active (on) when the input voltage is at a low level (V| # Vi), and column inputs are active +Pin 15 is the single-tone disable input. absolute maximum ratings over operating free-air temperature range (unless otherwise noted) Operating free-air temperature range, TA... 6.6 e eee e ees = 830°C to 70°C NOTES: 1. All voltage values are with respect to the Vgg terminal. 2. For operation above 25°C free-air temperature, derate linearly to 736 mW at 70°C at the rate of 9.2 mW/°C. TEXAS % INSTRUMENTS 0ST OFFIC 60X 088203 + DALLAS. TEXAS 78268 2-159

recommended operating conditions | Suppiv vottege, Vopr OT Row inputs (off High tevel in . orieve oa eee Wik [ait emerinputs “0.7 Vo voo.| Column inputs (off) Vss 0.1 Vpp. 1 input voltage, V v Low-level input voltage, Vit ‘All other inputs Vv. 0.3 Vp [ Contact resistance between row andcolumninputs | 100 | | [Tone-ourput loadresiatince, RLY 288 | Operating free-ir temperature, TA electrical characteristics over operating free-air temperature range (unless otherwise noted) [ aRAMETER TEST CONDITIONS uniT [Gotu orrowinpat OT tC | Single-tone-enable input resistance toVop | Ta= 25°C i 20ST [rate owe | Voo=3V,ion=02ma [2 Vpp = 10V. ton = 0.5ma [9 Vo High-level output vol v on Me tput vokeae |Tranamitter switch | Vpp = 35V. low= -15mA | 15 25 + output Yoo =10V, Jon == 40ma [8 | Vop =3V, lop = -0.2ma |i | level tage, m v Voi Low-level output voltage, mute output eS Vpp = 10V, Vo = OV [0 | Vp = 3.5.V, See Note 3 Dep _ Operating current Vpp =10V, See Note 3 [0] operating characteristics over recommended ranges of operating free-air temperature and supply voltage {unless otherwise noted) [ ParamereR ‘TEST CONDITIONS? UNIT [ Row tone | RL = 3309, 317400 500 Ta = 25°C 396600620 | ™ Preemphasis (column tone to row tone) ee [Duattone output distortion (seo Note 4) | op AV POY [Quiescent tone-ourput power 80 | am] Tone-output rise time (see Note 6) ns Unless otherwise noted, test conditions are: RL = 620 9 for Vpp < 5 V or RL = 3302 for Vpp > 5 V. Crystal parameters are the following: f = 3.579545 MHz +0.02%, Rg < 1009, Cy = 18 pF, Cy = 0.02 pF, Cy = 5 pF, Lu = 96 mH, NOTES: 3. Operating current is measured with all outputs unloaded, one row input connected to one column input. and normal oscillator input (Ta at O°C to 70°C). 5. This is the time required for output to change from its quiescent value to 90% of its final rms value. ee TEXAS id INSTRUMENTS 2-160 POST OFFICE BOX 655303 * DALLAS, TEXAS 75265,

Typical row and column stairstep approximations of sinusoidal outputs are shown in Figures 1 and 2. The row and column outputs are added together resulting in a typical dual-tone waveform as shown in Figure 3. Spectral analysis of this dual-tone waveform shows that all harmonic and intermodulation distortions are typically 30 dB below the strongest column-tone fundamental. —. _ =, a > ' : 2. ws, Pod ‘, : ia ZX rn’ = ros . 3 ed SS LS aed i. wo | Le “a 0.2 msidiv 0.2 maldiv 0.2 msidiv FIGURE 1 FIGURE 2 FIGURE 3 distortion considerations The following formula is used to calculate the total harmonic distortion of a single row or a single column: Wat2 + Vat2 + Var? + Ver2 +... + Vite THD = {>< 100% Vit where V2¢ is the second harmonic of the fundamental frequency V1f waveform and so on. The dual-tone total harmonic distortion is: Nor2 2 2 2 2 2 Wer2 + Vec2 where VeR and VEC are the row and column fundamental frequency waveforms, and V2R and V2, etc., are the corresponding harmonics. The total intermodulation distortion is: vimp2 = (Vig + Vicl2 + (Vig - Vicl2 +... + (Var + Vacl2 + (VaR - Vacl2 A relatively simple method of distortion measurement uses @ spectrum analyzer to relate the harmonics to the fundamental frequency waveform. The tone encoder spectrum indicates the harmonics and intermodulation distortion at least 30 dB down relative to the column tone. Another method for distortion measurement of the dual-tone waveform is to compare the total power in the fundamental frequencies with the total power in the various harmonics plus intermodulation on a signal analyzer. The encoders provide an output distortion of — 20 d8 maximum when operated between 3.5 V and 10 V. If operated between 3 V and 3.5 V, some clipping occurs at the output causing the distortion to exceed the — 20 dB level TEXAS % INSTRUMENTS POST OFFICE BOX 055209 « DALLAS. TEXAS 78205, 2-161

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APPLICATION INFORMATION

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1 @ sd ;? @ 0 "2N3906 VoD cor 2 ! i« . 5 Yen 6; SINGLE. COL 3 | 1 15) Fone (9) 3 t 1 24ko pismaLe COL fy ~~~ ©» H on 1 (ro |MUTE put] t Q ! tail TRansrreR O xrat ' t foureur osc} @) 1 t OUTPUT] ! XTAL PARAMETERS ' =O. wef) | . I TYPICAL VALUES hreanel ! Q I D1, D2, 03, D4 = 1N4004 Cy = 5 pF H ! DS = 1N4743 (13 V) 1 = 3.579545 MHz tL -_ SIDETONE BALANCE NETWORK ! 1 ' | H \\ © ] ch | i 1 ® _ t 1 I Gs —- PTT TSpeTONESALANCE NETWORK FIGURE 4. TYPICAL APPLICATION USING HYBRID COIL SIDETONE-BALANCE NETWORK,