MK53731 STMICROELECTRONICS | Alldatasheet
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- MICROELECTRONICS MK53731 SINGLE NUMBER PULSE TONE SWITCHABLE DIALER = SINGLE CHIP DTMF AND PULSE DIALER = SOFTSWITCH CHANGES SIGNALING MODE. ia FROM PULSE TO TONE See = RECALL OF LAST NUMBER DIALED (up to 28 get eee digits long) Mey yl Real = FLASH KEY INPUT INITIATES TIMED HOOK Nat FLASH = TIMED PABX PAUSE DiPts 020 = 8 TONES PER SECOND DIALING IN TONE MODE AND 10 PPS IN PULSE MODE ORDERING NUMBERS : MK53731NO0 (DIP18) = DTMF ACTIVE UNTIL KEY RELEASE MK53731D (S020) = MINIMUM DTMF DURATION/SEPARATION GUARANTEED (74/54ms) + PACIFIER TONE PROVIDES AUDIBLE IND DESCRIPTION CATION OF VALID KEY INPUT FOR NON. _ The MKS3731 is a Silicon Gate CMOS IC that pro- DTMF KEY ENTRIES. vides necessary signals for either DTMF or loop dis- s POWERED FROM TELEPHONE LINE, Low —oo"!nect (pulse) dialling. The MK53731 buffers up to OPERATING VOLTAGE FORLONGLOOP AP. _28 digits into memory that can be later redialed with PLICATIONS asingle key input. This memory capacity is sufficient for local, long distance, overseas, and even compu- Figure 1 : Pin Connections (top view). turized long-haul networks Users can store all 12. signaling keys and access several unique functions with single key entries. These functions include : wdi 18 by PULSE OUTPUT Last Number Dialled (LND), Softswitch, Flash and wove | 2 17 B vs Pause. Figure 2 shows the keypad configuration. ads 16D A ALND key input automatically redials the last num- eds she ber dialled. ads oweuba Two features simplify PABX dialling. The PAUSE vde Che key stores a timed pause in the number sequence. a Redial is then delayed until a outside line can be ac- osc: 7 42 A) MUTE OUTPUT cessed or some other activity occurs before normal oscz Ye 11,7 PACIFIER TONE signalling resumes. The FLASH key simulates a aqe to F) orwrourrur 560ms hook flash to transfer calls orto activate other Sa special features provided by the PABX or a central office ve Cs 20 f PULSEOUTPUT Figure 2 : Keypad Configuration. ove CH 2 19 FD Ks = a ays whom BEE = Bays viDR . i — Bas so ef 5} 6 Po v- C6 18 [D L ~ (SUITCH} osct C7 14D mOTEOUTROT al osce Cl} 8 13 [TD PACIFIER TONE a | Gays 12 FD orm oureut a TRAE naGrmSI791 1 wyiess gg 7929237 0053488 TL? mM ———__1@ 141
FUNCTIONAL PIN DESCRIPTION Table 1. Output Tone Duration. onl ‘ ” V+ | T<32ms No Output, Ignored by Pin 1. V+ is the positive supply for the cirouit and MK53731. must meet the maximum and minimum voltage re- z quirements. (see Electrical Specifications). | sams <7 <76m6 + Tox| 75ms Duration Output | MODE Input. Pin 2. MODE determines the dialer's defauit _* Note: Tro Isthe keypad debounce ime which s Wplcaly 22 ms. operating mode. When the device is powered up or Wien reqialing in the tone mode, each DTMF output the hookswitch input is switched from on-hook, | (V+), is 75 ms duration, and the tone separation (intersig- to off-hook, (V-), the default determines the signal- cia ig 50 ms ing mode. A V+ connection defaults to tone mode ¥) 7 operation and a V- connection defaults to pulse mode operation. “ When dialling inthe pulse mode, asoftswitchfeature ‘i : the device. Thi will allow a change to the tone mode whenever the _-Pin 6 Is the negative supply input to the device. This “key, or softswitch, is depressed. Subsequent "key _ is the voltage reference for all specifications. inputs will cause the DTMF code for an* tobe dialed. The softswitch will only switch from pulse to tone. Af ter retuming to on-hook and back to off-hook, the OSC, OSC2 partwill be in pulse mode. Redial bythe LND key will Pin 7 (input), pin 8 (output). OSC1 and OSC2 are repeat the softswitch. connections to an on-chip inverter used as the tim- a ing reference for the circuit. Ithas sufficient loop gain C1, C2, C3, C4, Ra, R3,A2,R1 | to oscillate when used with a low-cost television Keyboard inputs. The MK53731 interfaces with _color-burst crystal. The nominal crystal frequency is either the standard 2-of-8 with negative common or —_ 3579545 MHz and any deviation from this standard the single-contact (Form A) keyboard. is directly reflected in the Tone output frequencies. A valid keypad entry is either a single Row con- —_The crystal oscillator provides the time reference for nected to a single Column or V- simultaneously all circuit functions. A ceramic resonator with toler- presented to both a single Row or Column. In its ance of + 0.25 % may also be used. quiescent or standby state, during normal off-hook operation, either the Rows or the Columns are at a logic level 1 (V+). Pulling one input low enables the © OTMF OUTPUT ae on-chip oscillator. Keyboard scanning then begins. Output, Pin 10. An NPN transistor emitter with acol Scanning consists of Rows and Columns alter. lector tied to V+ drives the DTMF OUTPUT pin. The nately switching high through on-chip pullups. After transistor base is connected to an on-chip opera both a Row and Column key have been detected, nal a if ha nth nd the debounce counter is enabled and any noise tones. Figure 7 shows the timing at this pin, {oouncing contacts, etc.) is ignored foradebounce — The DTMF OUTPUT is the summation of a single period (Tko) of 32 ms. Atthis time, the keyboard is Row frequency and a single Column frequency. A sampled and if both Row and Column information typical single tone sine wave is shown in Figure 4. are valid, the information is buffered into the LND This waveform is synthesized using a resistor tree location. if switched on-hook (pin 17 to pin 1), the with sinusoidally weighted taps. keyboard inputs are pull high through on-chip pull- up resistors. ‘The MK53731 is designed to operate from an unregu- In the tone mode, it 2 or more keys in the same row _ lated supply ; the TONE LEVEL is supply independent, or if 2 or more keys in the same column are de- _and the single row tone output level willbe typically : pressed a single tone will be output. The tone will corres-pond to the row or column for which the 2 Tor = 128m +148 keys were pushed. This feature is for test purposes, and single tones will not be redialed. ; Also in the tone mode, the output tone iscontinuous The DC. component of the DTMF output while active in manual dialing as long as the key is pushed. The _is described by the following equation : output tone duration follows the table 1 Voci = 0.3 x V+ + 0.5V 218 142
Figure 3 : MK53731 Block Diagram. Hl ar) Lt Tay te I lf [Hamill Th i (Tels |sJ=lelele} \\7 ree Pee a | l l-[r] & ze 8 tefeete] = Boe 6 Bo eaot) a 2 Fy 143
DEVICE OPERATION (Tone Mode) When the MK53731 is not actively dialing, it con- (measured from initial key closure). Output tone du- sumes very itle current. While on-hook, all keypad ration is shown in Table 2, input pins are intemally pulled high. Row and Col- The MK5371 allows manual dialing of an indefinite umn inputs assume opposite states off-hook. The number of digits, but if more than 28 digits are dialed, Circuit verifies that a valid key has been entered by —_the'§3731 will “wrap around”. Thatis, the extra digits alternately scanning the Row and Column inputs. If beyond 28 will be stored at the beginning of the LND the input is still valid following 32 ms of debounce, buffer, and the first 28 digits will no longer be avail- the digitis stored into memory, and dialing beginsat- ple tor redial ter a pre-signal delay of approximately 40 ms Table 2: DTMF Output Frequency. ROW 1 697 699.1 +0.31 2 770 766.2 0.49 3 852 8474 0.54 4 941 948.0 40.74 COL1 1209 1215.9 +0.57 2 1336 1331.7 0.32 3 1477 1471.9 0.35 Figure 7 : Tone Mode Timing. ou seouece [7] [3] Cas) G) een ern exten enter io) [ease] a wr OS USS...) rer ourrur oe F + 2 fF ~ i ae motes fi rs | on woseeseee Noto For this oxamplo, Key entries are < 76 ma, bul 32 ha 145
Figure 8 : Pulse Mode Timing. ome seournce (7) [1] Coause) [i] ere omen ewe ae 2 © cme © sir? ee ee wo I HL) Coes) a soos uw ur tp PACIFIER ars NORMAL DIALING (off-hook) HOOK FLASH Normal dialing is straightforward, all keyboard en- Look flash may i ; lormal $ | , y be entered into the dialed sequence tries wil be stored in the butter and signaled in suc- at any point by keying in the function key, FLASH. cession. Flash consists of a timed Break of 560 ms. The FLASH function is stored in memory, but it will not LAST NI q ‘ST NUMBER DIALED (LND) be redialed as such. When a FLASH key is pressed, no further key inputs will be accepted until the hook- LND flash function (560 ms break) has been dialed. The key input following a FLASH will be stored as the in- i , z itia digit of a new number (overwriting the number tae qumber dialing is accomplished by entering the Giated prior to the FLASH) unless it is another i FLASH. Consecutive FLASH entries after a number PAUSE is dialed will be stored sequentially in the LND mem- ory anda subsequent LND entry will cause the redial of that number with a delay, but not hookflash +-ETC breaks, at the end of the redialing sequence. When redialing in tone mode, MUTE OUTPUT will remain ‘A pause may be entered into the dialed sequence active during the flash delay period. at any point by keying in the special function key, PAUSE. Pause inserts a 1.1-second delay into the dialing sequence. The total delay, including pre-digi- _ SOFTSWITCH tal and post-cigital pauses is shown in Table 3. When the dialing in the puise mode, a softswitch fea- ture will allow a change to the tone mode whenever seg 2qe9237 0053493 384 MB — 146
the * key, or SOFTSWITCH, is depressed. Sub- pulse to tone. After returning to on-hook and back sequent * key inputs will cause the DTMF code for _to off-hook, the part will be in pulse mode. Redial by an * to be dialed. The softswitch will only switch from the LND key will repeat the softswitch. Table 3 : Special Function Delays. Each delay shown below represents the time required from after the special function key is depressed until a new digit can be dialed. The time is considered "FIRST" key is all previous inputs have been completed dialed. The time is considered “AUTO’ if in redial, or if previous dialing is still in progress. | Functon | Frevauto |] Belay fps ~~] [Pulse Tone a a AUTO 1.85 a a a AUTO. 2.50 ABSOLUTE MAXIMUM RATINGS: Parameter [Value Unit _| [DoSupeivvege Cos | | Maximum Power Dissipation @ 25°C | 80m | * All specifications are for 2.5 Volt operation ang full operating temperature range unless otherwise stated. ELECTRICAL CHARACTERISTICS (Tamb = 25°C unless otherwise specified) DC Characteristcs [ne [symboi[ Parameter | Min. | Typ. | Max. | Unit [Notes | in a el TONE [| Vue [Memory Retention Votage TS || Tt | | [ts [ stand-by Curent To Tt |v | | [| twa [Memory Retention Curent | 5 | 75 | wv | 56 | |__| Vwure [Mute Output Operating Voltage | te || Tv C7 | |__| tr | Operating Current (Tone) || 800 | 00 | A | 2 | || te | Operating Current (Pulse) | (150 | 250 | wa | 2 | |_| hw [Mute Oupur@@syy a ma | | Sink Cureni@ (vy TT ma | |_| ta | Pulse Output Sink Curent Tt | 2 TT mw] 8 | |__| tec | Pacitier Tone SinwSouce (250 | 500 | | A | | [| key | Keypad Pullup Resistance || too | —Ssd| Ko | |__| kro [Keypad Pulkiown Resistance | S| 0 | S| | |__| vu | Keypad input Level-iow | Tove] v || |_| vin [Keypad inputLevel-high sve] ve Tv | |__| Vewse | Operating Vottage (puisemode) Tt | foo Lv || Notes : 1. Allinputs unloaded. Quiescent Mode (Oscillator off).
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- Proper memory retention s guaranteed ifeither the minimum Ina is providedor the minimum Vue. The design doesnot have to provide both the minimum current or voltage simultaneously. 7. Ml wge were schvatort oe oto ah key ery ented. 147
‘AC Characteristics - TONE MODE [we [symboi[ Parameter | Min. | Typ. | ax. | Unit | Notes | [| tue [Tone GutputNoKeyDown TT 80 [atm |_| pe Peers STE el 173, 194 mvVims | [| Pa _| Pre-emphasis, High Band [ia {2 [26 |e | | a or '+ = 3.5V) vo [| fe [Tone Outputoad Tt | Ka | [| Ts [Tone Output RiseTime | Tt Ts Ts [| pis | Output TMF Distoion Ts Tc Pe Ts | [| ta [Tone signatingRate Ts tse | [1 | Toso | Presignal Delay | Ts | | [2 | Tis | inter-signal Delay (repertoy) | | | ms || [| Tour [Tone Output Duration (repertoy) | 4 Te ms | Notes : 1. O dBm equals 1 mW power into 600 2 or 775 mVolts Important Note. The MK53731 is designed to drive a 10k load. The 600 2 toads only fr reterence. 2. Single tone (low group) as measured at pin 10 Ts = 25 °C. 4. Supply voltage = 2.5 Volts. 5. Time from beginning of tone output waveform to 90 % of final magnitude of either frequency Crystal parameters suggested for proper operation are Fis < 100 22, Lm = 96 MH, Cr, 0.02 pF, Cy = SpF, f = 3.579545 MHz and C, = 18 pF. 6. Time from initial key input until beginning of signaling. ‘AC Characteristics - KEYPAD INPUTS, PACIFIER TONE (numbers in left hand column refer to the limiting diagrams) [ne [symbot[ Parameter | Min. | Typ. | Max. | unit | Notes | [3 | Tw [Keypad DebounceTime | te | ms [| [| Fes | Keypad Scan Frequency | oc |e | [| Fer | Frequency Paciier Tone | | S00 |e || [4] ter [Pacifier Tone Duration | | ms [| [_[ tHrP [Hooktiash timing TS 80 | ms Tt | Note: 1. Crystal oscillator accuracy directly affects these times. AC Characteristics ~ PULSE MODE OPERATION [we [symbot[ Parameter Min. | Typ. | Max. | unit [Notes | [ [Pa [Pusepate CT to Ts | [5 | Po | PedigialPause | S| a | ms | [6 | toe | intwiigial Pause | so | ms | 2 [7 | Two | Mute Qveriap time | Ts | | (re [ts [Breaktme CTC co Ts [| Lo Tw [Make time ao J ms Te | Notes : 1. 10 PPS ithe nominal ae, 2. Figure 8 ilustrates this relationship. 148