M293

M293 STMICROELECTRONICS | Alldatasheet

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Technical content

7 7) SGS-THOMSON MICROELECTRONICS M293 EPM 32 ELECTRONIC PROGRAM MEMORY FOR 32 STATIONS = ONE CHIP INCLUDING CONTROL AND NV semiautomatic or manual modes. The search speed MEMORY is controlled externally by an RC network and is a SUPPLY VOLTAGE Vop =5 V+5% Vpp = 25 V+ adapted internally to the various bands and mode 1 V (only for storage and reading) of operation. In the automatic mode the M293 works = AUTOMATIC, SEMIAUTOMATIC AND MA- in conjunction with the TDA4433, which recognizes NUAL SEARCH MODES TV stations and converts the AFC-S-curve into a = MANUAL SEARCH CONTROLLED BY ONLY digital command. The stations are selected by ap- TWO KEYS (up and down). THE SEARCH plying a static bit binary word. A strobe input is also SPEED IS AUTOMATICALLY INCREASED provide. A 7 segment decoder-driver (e.g. SMOOTHLY WITH THE TIME TDA4092) can be connected to the same lines for = 4 BAND OUTPUTS WITH STEP-BY-STEP SE- Program number display. LECTION AND THE POSSIBILITY OF SKIP- A serial information output is provided so that using the M191, the varicap voltage in the form of a linear . we ADDRESSING AND COPY CAPA- bar and the selected band can be displayed on the = EXTERNALLY ADJUSTABLESEARCHSPEED Soh a = 445 TO 510 kHz CLOCK OSCILLATOR The M293 is available in a 28 lead dual in-line plas- = VOLTAGE SYNTHESIZER, 8192 STEP RES- __ tic package. OLUTION : = FINE TUNING IN 8 STEPS, STORABLE FOR EACH PROGRAM SEPARATELY = MINIMUM EXTERNAL COMPONENTS « INTEGRATED DIGITAL POWER-ON RESET (1 second) = TECHNICAL NOTE TN 153 AVAILABLE Vite of A) S DIP28

DESCRIPTION

The M293 is a monolithic integrated circuit con- ORDER CODE : M293B1 _ _ structed in N-channel silicon gate technology, de- , _ Signed to control a varicap tuner with a resolution of 8192 steps (13 bits) via a D/A converter, using the |__ Principle of voltage synthesis. | The device also includes a 544 bit NV Memory for storage of 32 stations. Each station is identified by a 17 bit word containing the information for tuning voltage (12 bits), band (2 bits) and fine tuning (3 bits). The circuit is able to operate in automatic, January 1989 Wi? | 121

[Symbol [Parameter | Value | nit | Off State Input Voltage (except pin 10) Pin 10 28 Vv | Pins 11-19 75 mA ton | Ouiput Curent (pin) Tema [Por | Total Package Power Dissipation | tw Stresses above those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress rating only and functional operation of the device at these or any other conditions above those indicated in the operational sections of this specifi- cation is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability PIN CONNECTIONS

7 GND q: 2ef) cATY

PA [3 261) VHF IIL PB (j« 2s) VHF 1 Pc (js aay} z PO Qe 23) v PE Q7 22) x yaory (le 2if) sToP/AF C2 search = (]9 20f] STOP/AFC1 | MEMORY — ho ssf) tune our TIMING. Frour | 18f) cLock our Yoo jiz vf} DATA OUT | osc.t (ji3 we ARTO! osc. rs 150] TEST Earrery gy scs-tHomson

192 MICRORLECTRONICS

RECOMMENDED OPERATING CONDITIONS [Symbol [SSS arameter—SSSS*dYSS Valu | Uni | Supply Voltage 4.75 to 5.25 Input Voltage Vo (ott) | Off State input Voltage (except pin 10) Max. 13,2 Vv Pin 10 Max. 26 Vv | lou Output Current (except pins 11 - 19) Max. 2.5 mA Pins 11-19 Max. 5 mA Output Current (pin 2) Max, — 0.25 | tps __| Delay between Memory Timing and Memory Supply Pulses Clock Frequency [| 500 ke | Operating Temperature c [| Ro _| Search Speed Resistance (pin 9) 18 to 330, KQ Search Speed Capacitance (pin 9) [| Max.100 | nF | ts | Delay of Vee from Voo at Power-on Rise Time of Vep (during storage or reading) 2 to 10 in Serial Resistance of the Ceramic Resonator / BLOCK DIAGRAM Figure 1. T_T TDA 4092 mi90 FF DISPLAY DRIVER: keveoaRD [PC , ENCODER [pp Yss Yoo TEST (GND) 5¥) PIN Fr CL) | wv j Tt Teal, 26h lt PA. __ re 5 pp[UHE. | BAND OUTPUTS M104 Pe — | leo 6 ze |CATY of PC [pe| _— 7 M105 19) TUNING Remote fP0 STROBE IN M293 VOLTAGE OUT contro. [pe 2 RECEIVER foe MUTE OUT EPM32 "— fUNiNG our | ‘OUT OSC.OUT 14 t 21

1 SOOKHz x

| 22 DATA t INTRO| Y | —- 2424 16 9 se} StOCK i M191 AUTO/MAN. SEARCH ‘ON-SCREEN SPEED DISPLAY DRIVER: ‘YI icicrosuscTaomes | 123

STATIC ELECTRICAL CHARACTERISTICS (over recommended operating conditions) Typical Values are at 5 V and Tamp = 25 CT [svmect | rarameter | ens | r Gonal E on un arameter est Conditions | min. | Typ. | Max. | Vi | input Low ee Vol onage [es-ecer2s | | CT os 16-20-21-22 } 23-24 vot [-as-e6-er-ae [ = 16-20-21-22 3.5 23-24 Vor | Output Low 25-26-27-28 | Voo=475Vlo.=1mA | | | 3 | Vol [e718 | Voo=475V lou = 100yA_| | | 0a | Veo =475Vlo.-SmA || | 8 | loom | Output Leakage Von =825V Yowom=132v] | | 100 | Current [ 119 Vow =8.25V Vowm=t92v] | | 50 | HA [0 | Yoo =4.75V Vowm=26v | [| 100 | i Input Low Current 3-4-5-6-7 Vop =5.25V Vi =0.8V - - 0.4 1622-23-24 [2 [Woo =825VV,-cav | | _[-16 [too | Stpniy Curent_[ 42 | Voo=s2sv «| | 20 | 0 | ma | Memory Supply Ver =26V === Current | [Average| | 48] | Average] | | 2 | DESCRIPTION (all timings are given with fret = 500 kHz) The circuit description follows both pin sequence can also work with Remote Control receivers with- and pin function. out any strobe output, the strobe function is useful, for example, to recall the stored tuning voltage after PIN 1. Vss a search. The substrate of the integrated circuit is connected This input is active low and has an internal pull-up to this pin. to 6 K (typ). PIN 2. PROGRAM STROBE INPUT/MUTE INPUT A second mute cycle restarts when the input goes low and the memory is read after 110 ms. ; PROGRAM STROBE INPUT. Although the pro- | gram change is internally detected and the M293 ST/ iacroauscTaomes 124

[—Presram_ [PAT PB[Pc[PD[PE| Program | PA PB | Pc | PD | Pe |

1 Lye; eFPuye 17 Li} e}ue} ty] Hu

2 H}eE|LJeIL 18 H}L]UL]L]H

3 Ly H}evuye 19 L]H |e] tL] H

4 H] HJ EL] LIL 20 H}H]t )L IH

. 5 Lye}; uHfP eye 24 t]te)H | tH 6 so 22 Hj}tL]HI|L]H

7 Ly} H] AH] ete 23 L | H}|HI] LH

) 8 H| HJ] HJ] LL 24 HH} H{|H|L|H

9 Lye} epuye 25 [ee oe

10 H]} UL] LJ] HI L 26 H{| tL] L]HY]H

1 L}H} LP AH] Le 27 L|H}t]HIH

12 H}/H] tL] HI e 28 H}]H]-L|HYH

13 Lyu}Ht Ate 29 uc} tc}H HI H

14 H}L]HI HL 30 H| LJ] H|HIH

15 L H H H L 31 L H H H H

16 H}H]H{HIL 32 H|H]H!]HI{H | PIN 8. MEMORY SUPPLY VOLTAGE During both write and erase cycles the memory situ- : : A ation is checked continuously ; therefore after each A supply voltage of 25 + 1 V has to be applied to this senting j . : write or erase pulse a read operation is carried out. pin during the modify and read cycles. The write or the erase operations are stopped as MODIFY CYCLE soon as the result of the read operation is valid. A modify cycle consists of three steps : WRITE CYCLE. The peak of the current flowing | 4. All'"1"s are written in the bits of the selected through pin 8 during a write operation is shown in word. fig. 4, while fig. 5 shows the envelope of the same 2. All bits of the selected word are erased (all current. | an . | "O"s). The typical write time is 3-4 ms for the first cycles 3. The new content is written. and increase to about 30 ms after 1000 cycles In this way a constant aging of all the bits of the word is obtained. Figure 4. | 40mA ama 6mA | | mn | | n : 62 32] 4) 6us |artER ABOUT 30msec. o/h ScscTHomsom 126

Fig. 7 shows the waveform of the current during a read operation Figure 7. ; 6mA | — 44. | Baus 480msec $5682 PIN 9. SEARCH SPEED PIN 11. FINE TUNING OUT An external RC network is connected to this pin in Fine tuning information is available on this pin in the order to set the frequency of the internal oscillator form of a square wave having a frequency of which, in turn, sets the scan speed during search. 15.625 Hz and duty cycle variable in 8 positions as The search speed ratios in the bands are explained indicated in fig. 8. in the description of pins 22, 23, 24 (UP/DOWN Ma- nual) and of pins 20 and 21. PIN 10. MEMORY TIMING OUTPUT This output gives the timing for the pulses to be ap- plied at pin 8 during the modify and read cycles. The | output consists of an open drain transistor. | Figure 8. FINE TUNING OUTPUT | 64S | a | ce es ee 1 ' Pre 1M a T _ __ $-5098 ey ep ses-THOMSON STF mecromscraoxics 128

The voltage generated after filtering is fed to the PIN 12. Vop ane ee angie. re receive bY a smalll Af ans pin has to be connected to a 5 V + 0.25 V sup- . ply. The Fine tuning function operates as follows : Whi . . fe ni 1 en the Vpp is applied to this pin an internal power - at Start of the Apres een the onreset of 1 sec is generated : therefore, for a cor- When the search has been completed it is rect reading of the memory, the Vep supply voltage ~ possible to operate on the FINE TUNING + com. must reach the value of 25 V within 1 sec after the oo ends Pe = cor presence of Vpp. The STORE command memorizes this informa- PIN 13-14. OSCILLATOR tion together with the 12 tuning voltage and 2 bit band orormmation, 9 o The internal oscillator operates with a cheap 445 to . When a memorized channel is recalled it is 510 kHz ceramic resonator connected as shown in possible to act on the FINE TUNING + com- fig 9. mands. If an external oscillator is used, the signal to be ap- Any change is Fine tuning is memorized only by the Pied must be 0.5 Ver min. STORE command. The output circuit consists of an open drain transistor. Figure 9. M293 M104 M293 13 % 7 16 1300 “th S500KHz InF 100pF 100 pF O- I I 100pF SS 100pF: 33M PIN 16. AUTOMATIC/MANUAL SEARCH MODE information, 5 bits for program information and 1 bit SELECTION which indicates that the system is in the search is pin j i Manual). The display is This pin is used to change the search mode. When mode (both Automatic or itis connected to Von the system works in Automatic 9/0 enabled at the band change. mode ; when itis connected to Vss the system works. These outputs are active low and incorporate a | manually. 10 KQ (typ) pull-up resistors. _ The change Auto-Manual or viceversa can be made PIN 18. CLOCK OUTPUT FOR EXTERNAL DIS- at any time without affecting other circuit functions. PLAY (M191) __ The input has an integrated pull-up of 30 K2 (typ.). A burst containing 16 clock pulses is available on | PIN 17. DATA OUTPUT FOR EXTERNAL DIS- this pin. This clock pulses are synchronized with | PLAY (M191) Data Information as described in fig. 10. A 16 bit burst is available on this pin. It contains the A pull-up of 10 KQ (typ) is integrated.

8 MSB of the digitized tuning voltage, 2 bits for band

Figure 10. cock - _ TRANSMISSION TIME = 992 ps REPETITION TIME = 18 ms __ _ 2ys oe BEEELCCEBL CLIC = =6 TONING | wee | BAND | PROGRAM TUNING VOLTAGE SEARCH : +1 5 90be : PIN 19. TUNING VOLTAGE OUT starting from this point the number of pulses remains

7 A 2" = 8192 step pulse modulated signal for the ire same but the pulses get larger unt tney reach

tuning voitage is available on this pin. le maximum content of the internal counter. The ae a output consists of an open drain transistor which of- | Pulse modulation is implemented by combination of fers a low impedance to ground when in the ON arate multiplier and pulse width principle. state. With a tuning voltage increasing from zero, the num- ber of pulses increases continuously up to 2° = 256 ; Figure 11. ait pie] | “if ! | 1 ova ve ve ~-----4 | UU U U LIL "SLILIJLILI UL + -——— own-up— saa tony eee scs-tHomson MICROELECTRONICS 130

PIN 20-21. STOP/AFC has been given just before an AFC control com- These pins are used only in automatic search mode. mes time the FAST UP speed is automati- When the M293 is in manual operation these pins cally reduced to half during each UP signal (ME- are disabled internally. DIUM UP = FAST UP/2). The STOP/AFC inputs are also disabled internally A DOWN signal preceded by at least an UP sig- during any program or band change for the duration nal will set the search to MEDIUM DOWN mode of the Mute signal. (FAST UP/4). These pins work according to the truth table given 3 - the next UP signal will switch the search to below : SLOW UP speed (61 Hz) a At this point the system is in normal AFC oper- M293 Pin 20 | M293 Pin 21 fatores to ation. TDA4433 Pin 2/TDA4433 Pin 6) ring voltage) B) AFC operation : when a station is perfectly tuned, the input signals coming from TDA4433 H t Up are at tuning condition. L H vow If the tuning moves lower than the threshold 4 4 N wee below 38.9 MHz, the pin 20 is put H and pin 21

0 Cperation is put L ; the 13 bit internal counter is moved with

These inputs have two different functions depend- SLOW UP speed to increase the varicap voltage. ing on whether the system is in the search or in nor- When a detuning occurs in the opposite direction mal operation (AFC control). the input 20 goes low and 21 goes high and the . . A tuning voltage is decreased with VERY SLOW The inputs have internal pull-up resistors of 30 KQ DOWN speed (7.6 Hz). typ. (10 KQ min). The increase or decrease of the tuning voltage is A) Search mode : after depressing the Search start stopped as soon as the input returns to middle key, the levels of the signals coming from the conditions. TDA4433, applied to these pins, control the Therefore during normal operation pins 20 and search function and determine when the search 21 act as the AFC control command. must stop, i.e. a TV station has been recognized. —_) Recall from memory : when the circuit is in auto- The circuit operates in the following sequence matic mode and a pre-memorized program is re- (see fig. 12 for reference and explanation of pins called from Memory, a fixed value of 8 steps 22, 23, 24 for definition) : (~31.2mV) is subtracted from the tuning voltage. 1 - after pressing the search start key the search This corresponds to a detuning of 0.6 MHz (UHF) occurs in the FAST UP mode. and of 0.3 MHz in VHF til into that part of the IF 2 - eventual transitions available on these inputs response curve which corresponds to the fully are ignored during the first 15 search steps if transmitted sideband. the system is in the UHF or CATV bands. At this point the AFC operation takes over as de- B ih Ifthe system operates in VHF | and Il! the first 60 Sofibed it poirt B above and the exact tuning is Search steps are ignored. The acceptance delay This feature increases the AFC capture range of 15 (60) search steps has been introduced to and relaxes the stability requirements of the Prevent the system from stopping at the previous tuner, voltage references and the D/A converter. station (for example if the search start command ep sermon JF isichosucrromecs 131

Figure 12. 3435 36 37 JeMHz 388 F RESPONSE 388 NORMAL AFC POSITION ~ -39.0MH> 33,4Mez 2oMte ——--+1 40 a9 PING Toa 6033 <308 >38,0MH2 PIN 2 Fast up | MeDiuM up £0 DIGITAL INFORMATION g'| ~S. } stop / NX a.omMz -—f-———-- -# f — . SSN wo fone f resto. / SQ se.emne in - ee RN] _ ae —— | PINS 22-23-24 CONTROL INPUTS X - Y -Z | The M293 accepts binary coded commands as follows : (x ]y¥ | z Function L H H_ | Memory Addressing/Store H L H_ | Band Selection H|HIL FT. L | Ly | Manual Mode (pin 16 L) { en Automatic Mode (pin 16 H) { ane H L L_ | Automatic Search Start (without band change) L H L Automatic Search Start (with band change) The inputs have integrated pull-up resistors of 30 KQ (typ). Commands are accepted after 30 ms of continu- | ous presence. A new command is not accepted until the previous one has been released. 1217 ky7 SGS-THOMSON “TU mcroauscracmes 132

Figure 13. x oy 2 x, MEMORY ADDRESSING/STORE x BAND SELECTION Pa MANUAL UP AUTOMATIC FT+ st, MANUAL DOWN! AUTOMATIC FT- — AUTOMATIC SEARCH START (WITHOUT BAND CHANGE) PS AUTOMATIC SEARCH START (WITH BAND CHANGE) $-5500 MEMORY ADDRESSING/STORE. The normal se- In order to protect the memory the store function is quence of program storage (program selection, disabled internally after one store cycle. Itis enabled search, store, new program selection and so on) can after a program change or a tuning operation (it is be changed in order to have the possibility to select not disabled by the AFC control). the memory position (program number) after the search. BAND SELECTION. The bands can be step-by-step | In this way the search is faster and continuous Selected with the following sequence : through the bands. [Tata Bus | When the key is pressed itis possible to select the = [Band | =SOMSB. «| =O«LSBCS memory position. When the key is released the store function is activated (with 30 ms of acceptance VHF Ul L L time). UHF L H . VHF | H L The proposed sequence of tuning and storage is as CATV H H described below : Only one band change is performed at each ac- Step Operation cepted command. 1 Tune in station (manually or automati- Disabled bands are automatically skipped. A band cally) can be disable by connecting the corresponding out- | 2 Press "Memory addressing/Store" put to VSS. key and hold it pressed MANUAL MODE UP/DOWN, AUTOMATIC MODE 3 Select the program where the tuning FT+/FT . The function of this pin depends on the fs . search mode that is determine by pin 11. 4 Release the "Memory addressing/ . | Store" key Manual : when a command is accepted the search At this moment 12 bits of the digitizedt begins at low speed. One second later, | uning voltage, 2 bits for band 3 bits the search speed is increased and it relative to Fine Tuning are stored reaches the maximum value after 3 sec- | If this solution for memory addressing/store is not onds. used, memorization will occur at the release of the Search speed Time | key in the memory position previously selected. | This command is disabled during the Automatic +8 Command accepted | search, During the store cycle any other operation 4 After 1 second is blocked. Only the program change command is +2 After 2 seconds | stored internally and executed when the store cycle +1 After 3 seconds is over. —PFE|scs-tHomson ‘Y/ iicrowrcTRomes 133

The search is correlated to the selected band as fol- Automatic fine tuning +/ : when the command is lows : accepted, the PWM signal present at the fine tuning Max search speeds : output (pin 11) is changed at the rate of one step Bands VHF | and VHF I: extemal rate divided V2"Y 480 ms. re by 3 Fine tuning is manual mode is possible switching Bands UHF and CATV: extemal rate divided temporarily the system to automatic modes as by 12 shown in fig. 14. When the end of the band is reached the search restarts from the beginning of the same band after a delay of 480 ms. Figure 14.

7 Yoo 1

AUTO/MAN. PIN 16

4 RS33KN

i iH z | +—— GND | | y Om FT + v | in S- seas AUTOMATIC SEARCH (without band change). VHF bands are scanned with the rate fixed exter- When the command is accepted the search starts nally. on the selected band. When the end of the bandis uring the STOP sequence the search speed is reached the search restarts from the beginning of automatically reduced as defined in the explanation the same band after a delay of 480 ms. of pins 20 and 21. | If the key is held depressed another search can start only if the key is released and connected again to © AUTOMATIC SEARCH (with band change). The vss. search is effected starting from the tuning position. During the search the tuning voltage is always When the end of band is reached, the band is auto- changing from lower to higher voltage levels. The Matically changed in the sequence described at pins search is automatically stoppes when the first sta- 22-23-24 (Band selection command). Disabled tion is found. bands are automatically skipped. The search is also stopped whenever a program se- PINS 25-26-27. BAND OUTPUTS/INPUTS lection command is given. . The search speed is determined by the RC network These SoeeNDe provided to select up to 4 bands connected to pin 17 and is correlated to the band. via externa s- . UHF and CATV bands are scanned with the rate _|f one or more bands have to be skipped, the corre- fixed externally divided by 4. sponding outputs have to be short-circuited to Vss. ‘TF isicnomzcmomes 134

Figure 15. The relation between pins and bands are as fol- lows : j pin 25 = VHF | pin 26 = VHF Ill 4 pin 27 = UHF pin 28 = CATV s- 5501 5 s&s: 18/17 | 0 Sones. | 135

Automatic Version. 28 > ice fe 25 z Bgtes z 4 z 38 = $322 ¢ g 3 = 9 | 9 | eo 9 6 aU & 2 a ? 4 4 y | 7 Ss, rT g Fl Pa and > al % 3 _ 4 ey . IH E a * to-4s 2 e g} sDefs _ ef zo » "7 Sa | gO 2 iH z =— — <r é KAA} kg {HHH Ss = w i | « sa)@ i] ge 380 sy, ese 3 —_ 3 5 ¢ yz l 1 BE fo a] 2 LY s2 |= | * : fj A pe Ee bg g ad ad so ‘a ~~ = ¥ = 8 T 424 é 3 ed (——o# | 8 fe iS & | e = . 1, zs ry a ee z sl = | a a jo YT ri | . ag (1H rn a ae nine st-—— | 2 3S S ae enonn gel | Pos C4 ° fe TT af! ws 2 ° g 24] K-08 rman a [tT] OF ei — aq Sj 5 | mes s+—H _ | oC : [C4 = s-] | | sedoodo glace: os | 3 By * gt ae 5B segewb? aa 16/17 . TT Fe SE 136

Manual Version. w _ z 22 . za br 2 eo: > 33 ¢ 2323 % 5 a Yi fe) O fe) fe) 9 ie) Oo i KH : ¢ o = al) « E 8 a a | Al Al 2 (3 g % & B = go B g a : z = @ 5 gt g z —>Al—H ae = Ee ¢ [| aoe SBe 3 3 eSe > ¢ J 3g aU z e fens FS z ° 24 { . aug 2 g = kt 3 ° o act 8 _ 2 ot ae 4 Cc) -42 = a, 8 aed 2 ey 2 i? Ts a 2 4 > a 27° Fone monn r7 i fa TTT 7 <a] ec - | — one yk | ES 8 Z ; | Ea Soy | iE 7y | Mrs § . 2 Bu z, <evouwets a feveevi? G57 SGS-THOMSON mae SJ4 Nacmosuscrnomes 137