AMI IZ STANDARD PRODUCTS $2559E/F February 1993 Features Wide Operating Supply Voltage Range: 2.5 to 10 Volts Low Power CMOS Circuitry Allows Device Power to be Derived Directly from the Telephone Lines or from Small Batteries, e.g., 9V Uses TV Crystal Standard (3.58MHz) to Derive all Frequencies thus Providing Very High Accuracy and Stability Mute Drivers On-Chip Interfaces Directly to a Standard Telephone Push- Button or Calculator Type X-Y Keyboard The Total Harmonic Distortion is Below Industry Specification DTMF Tone Generator Oscillator Resistor On Chip * On-Chip Generation of a Reference Voltage to Assure Amplitude Stability of the Dual Tones Over the Operating Voltage and Temperature Range * Single Tone as Well as Dual Tone Capability Two Options Available: E: Mode Select F:Chip Disable The S2559 DTMF Generator is specifically designed to implement.a dual tone telephone dialing system. The device can interface directly to a standard pushbutton Block Diagram Pin Configuration *oo Vop 01 xTAL =f >| ] | 2 | XMIT 5 OSCILLATOR +2 TRANSMIT MUTE 2] asamuz { a | f > ha] mute TFT INH 4 FO Vo (] 1 16 [7] TONE OUT | | at [rape] LI | | xmiT (] 2 15 |] MOSL/cD nz [1a}+>] now KevaoaRo aenwioen | 8h 8 STAGE or | 3 14 [7] Ry n3 [12> toGic ew SROUF COUNTER NETWORK eC] 4 13k, na [ir] I fen | $2559 | lt ee 12 [7 Rs | comwost [15] occ, +H & ADDER Vss [] 6 11 J Ra ry a ose; (} 7 10 [7] MUTE t1 Ek cK EN | y, Osc, Cl 8 9 [_] C a2 oo 0 4 c2[abery conunn PROS AMABLE Tet, | 8 STAGE nesisran | | c3 [5 }e>{xevgoanp Locic oan taro eB T | counter werwonk [7 a 2] . | | [16] TONE OUT Lo Z Veg [5]$2599E/F AMI iZ STANDARD PRODUCTS DIMF Tone Generator General Description (Continued) telephone keyboard or calculator type X-Y keyboard and operates directly from the telephone lines. All necessary dual-tone frequencies are derived from the widely used TV crystal standard providing very high ac- curacy and stability. The required sinudsoidal wave- form for the individual tones is digitally synthesized on the chip. The waveform so generated has very low total harmonic distortion. A voltage reference is generated on the chip which is stable over the operating voltage Absolute Maximum Ratings February 1993 and temperature range and regulates the signal levels of the dual tones to meet the recommended telephone industry specifications. These features permit the $2559 to be incorporated with a slight modification of the standard 500 type telephone basic circuitry to form a pushbutton dual-tone telephone. Other applications of the device include radio and mobile telephones, remote control, Point-of-Sale, and Credit Card Verifica- tion Terminals and process control. DC Supply Voltage (Vpp-Vss) bce eee eee ete e eee Ln beeen e ett teen ener ees + 10.5V Operating Temperature ........................0.0. Com-0C to + 70C, Ind-45C to + 85C, Mil--55 to + 125C Storage Temperature .............0... 0... cere eee eee Power Dissipation at 25C ...........0..0...0. 0.00222. Ta) . | Ltn nee eee terete renee ees 30C to + 125C $2559E/F Electrical Characteristics: Symbol Parameter/Conditions oe a Min. Typ. Max. Units Supply Voltage Tone Out Mode (Valid Key Depressed) 25 10.0 V Voo NonTone Out Mode (No Key Depressed) 16 10.0 V Supply Current Standby ( No Key Selected, Tone, XMIT 3.0 0.3 30 pA loo and MUTE Outputs Unioaded) 100 10 400 yA Operating ( One Key Selected, Tone, XMIT 3.0 1.0 2.0 mA and MUTE Outputs Unioaded) 10.0 8 16.0 mA ToneOutput Com 335 Com 565 Single Tone Row Tone, RL = 390Q 35 Ind 255 465 Ind 660 mVims SO56QE/F Mil 235 Mil 700 Com 380 Mode Output 5.0 Ind 300 540 710 mVrms Mil 250 Com 380 Vor Voltage Row Tone, RL = 2400 10.0 tnd 300 550 735 mVrms Mil 250 dBcr Ratio of Column to Row Tone (Dual Tone Mode) 2559E/F 3.5-10.0 10 2.0 3.0 dB %DIS Distortion * 2559E/F 3.5-10.0 7 %IZ STANDARD PRODUCTS | S2559E/F February 1993 DTMF Tone Generator $2559E/F Electrical Characteristics: (continued) Symbol Parameter/Conditions (on-tss) Min. Typ. Max. Units XMIT, MUTE Outputs V, XMIT, Output Voltage, High (lo = 15mA) 3.0 1.5 1.8 OH (No Key Depressed){Pin 2} (lo4 = 50mA) 10.0 8.5 8.8 lor XMIT, Output Source Leakage Current, Vop =0V 10.0 100 pA V MUTE (Pin 10) Output Voltage, Low, 2.75 0 0.5 OL (No Key Depressed), No Load 10.0 0 0.5 V MUTE, Output Voltage, High, 2.75 2.5 2.75 oH (One Key Depressed) No Load 10.0 9.5 10.0 lo MUTE, Output Sink VoL =0.5V 3.0 0.53 1.3 mA Current 10.0 2.0 5.3 mA lon MUTE, Output Source Vou = 2.5V 3.0 0.17 0.41 mA Current Vou =9.5V 10.0 0.57 1.5 mA Distortion is defined as the ratio of the total power of all extraneous frequencies, in the VOICE and above 500Hz, to the total power of the DTMF frequency pair. Table 1. Comparisons of Specified vs Actual Tone Frequencies Generated by $2559 Table 2. XMIT and MUTE Output Functional Relationship OUTPUT FREQUENCY Hz ACTIVE % ERROR OUTPUT DIGIT KEY INPUT SPECIFIED ACTUAL SEE NOTE RELEASED | vepressen | DIGIT KEY | = COMMENT R1 697 699.1 +0.30 R2 770 766.2 ~0.49 XMIT Vop High Can source at least R3 852 847.4 0.54 Impedance 50mA at 10V with R4 941 948.0 +0.74 1.5V max. drop C1 1,209 1,215.9 +0.57 C2 1,336 1,331.7 0.32 C3 1,477 1,417.9 0.35 MUTE Vss Vop Can source or C4 1,633 1,645.0 +0.73 sink current NOTE: % Error does not include oscillator drift.S2559E/F AMI iZ STANDARD PRODUCTS DTMF Tone Generator February 1993 Figure 1. Standard Telephone Push Button Keyboard ? -O--O--O --O-O- 4 eo Ry -O-O--O-- COMMON > 14 R, NN > 13], a 2 Ny, 12], i 3 > 11 Ry $2559 > 3 C, pte. Dt hes 9 Cy D8 Vg Vss I G G1 THRU G8 ANY TYPE CMOS GATE D1 THRU D8 DIODES TYPE IN914 2,3,4,5 ! 7,8, 9 10,14 12; 13,14 5 Figure 4. Stairstep Waveform of the Digitally Synthesized Sinewave 16 7 18,1920 21, 22,2324 25 26 27 28 29 30/31, 32 (Yop) 1.05 094 os 07+ > a w 064 3