Multimedia ICs On-screen display for VCRs BU2878FS/BU2871FS The BU2878FS and BU2871FS are character generator ICs for pattern display use in VCRs andtelevisions. The IC circuit is made up of avideo signal generator, analog switch, synchronization separator circuit, and synchronization signal detect circuit. The display RAM can store is 10 lines X24 characters, and the on-chip character data ROM can store either 64 or 128 different characters. @Applications VCRs @Features 1)16 line & 24 character display. 6)Built-in synchronous separation circuit. 2)64 (BU2878FS) or 128 (BU2871FS) character types. 7)Built-in clamp circuit. 3)For each line, the character size can be selected as ei- 8)Built-in synchronous decision circuit. ther 1% or 2X. 9)Compatible with NTSC, PAL, PAL-M, andPAL-N. Non- 4)Character output for composite video is white with black interlace mode can be selected. border. 5)Background color can be either white black or blue (black or white with PAL systems). @Absolute maximum ratings (Ta=25'C) Parameter Symbol Limits Unit Power supply voltage Vcc 0.3-~7.0 V Power dissipation Pd 750* mW Operating temperature Topr 20~75 c Storage temperature Tstg 50~150 c * Reduced by 6.0mW for each increase in Ta of 1C over 25C. @Recommended operating conditions (Ta=25C) Parameter Symbol Min. Typ. Max. Unit Power supply voltage Voo 45 5.0 5.5 Vv Input voltage Vin o _ Vop V LC oscillator frequency fosc 5.0 _ 10.0 MHz X'tal oscillator frequency | Xosc - Prec Hz Xtal oscillator frequency | Xosc tse - Hz 1 For NTSC. *2 For PAL, PAL-M, and PAL-N. 350Multimedia ICs BU2878FS/BU2871FS @Block diagram EQH a sypeT | 4 </cra 2 2 x 5 fe 2 | Xtal BE [/epsl|Sesl] s g 5 o/|3 5 a ey 8 3 eZEljoxre]/5a 8 9 2521/2 5se/|(Ss 8 ma + SlymaPsl|loaan oO SCK 2 He z Sl =| Hm) 19 |X talour E y = 8 5 aosl| = i g _ o= Ro2 Sad 2 cs} 3 tm ge O5ES oRge 3 18 | Ac 8 CFs) GSEs p |e = a A i a py SYNG Vertical sync 5 signal saparator Pll} ____ DATA 4 ie & CLK ciroull im) 17 | CSYNCOUT Test circuit t TEST 5 |} Blue back 16 | CSYNCIN vid ac Video signal video |-| analog = oulpul switch 3 composite Qo OSCout 6 3 16 | Deo 3 e RAM write b | address camp counter oscw | 7 | 14 | PORT ' Data selector DVss & eo 13 | AVbo at Character code} 58 RAM, 7 bits< 535 240 words G 3 Composite yout | 9 a3 sync signal jaa 12 | SYIN 3 o eeparation circult o 5 Character generator oP? he FROM 12% 18 bits, 3 2B 128/64 words o Ass | 10 8 11 | VIN On-screen displays Multimedia videoMultimedia iCs BU2878FS/BU2871FS @Pin description Pin No./Input/Output) Pin Name Function The synchronizing signal is used to determine the presence or absence of a video 1 Output SYDET signal, and the result is output on this pin (sync detect). Pind is "L" when a signal is detected, and "H" when no signal is detected. 2 Input CLK Clock input for reading data. Data on the DATA pin is read on the rising edge of the clock. | When the bit data is character data, the data address is incremented by 1 when 3 nput cs the writing to video RAM is completed. 4 Input DATA Control data input. Data is read synchronously with the rising edge of the signal on the CLK pin. 5 Input TEST IC test pin. Normally connected to GND. 6 Output OSCout For connection of capacitor and coil for the oscillator. Used as clock oscillator for 7 Input OSCin the OSD function. 8 -_ DVss Connect to system GND (digital circuit). 9 Output VOUT Video signal output 10 _ AVss Connect to system GND (analog circuit). 1 Input VIN Input for external video signal. Input a signal of 2VP-p. 12 Input SYIN Video signal input for synchronous separation circuit. 13 _ AVop Power supply(+5V) pin (analog circuit). Use as a port. 14 Output PORT1 a . , When pin 5 is "H" the crystal oscillator clock is output. 15 7 DVoc Power supply (+5V} pin (digital circuit). 16 Input CSYNCIN Composite sync signal input. Active low input. 17 Output |CSYNCOUT| Composite sync signal output. 18. Input AC "L" resets all ragisters and clears the RAM. 19 Output x tal For connection of a capacitor for oscillation, or a crystal. Used for blue back with 20 Input no signal. Use a crystal with a fraquency of 4fsc for PAL, and 2fsc for NTSC. * Function of the AC pin When the AC pin is set to L", all registers are cleared, and data is written to all RAM addresses (RAM clear function). For this reasonsend commands until writing of data to the RAM is complete. The time requires to write the data to the RAM is 3fose< 240 (sec.), 352 ROMMultimedia ICs BU2878FS/BU2871FS @lnput / output circuits ts Inputs Your 2,3, 4, 16 lt. 8 T input with pullup resistors Output cell Input Crystal oscillator cell i Input with pullup resistors SYIN ROM 353 5 3 : { 1, 14, 17 : 1 it q Multimedia video | | On-screen displaysMultimedia ICs | BU2878FS/BU2871FS Oscillator call Beem 3, a | @Electrical characteristics (Ta=-20C to + 75C and Vop=4.5V to 5.5V) Parameter Symbol Min. Typ. Max, Unit Conditions Teast Circuit L" input voltage Vite 0 - 0.3Vp0 Vv For CMOS input Fig.3 "H" input voltage Vine 0.7Vop _- Vop Vv For CMOS input , Fig.3 "L output voltage Vout - |0.1Vo0 Vv Forosc "1 Fig.1 "H" outpul voltage Vor | O.9Veo| Vv Forosc 7 Fig.2 "L" output voltage Vote _ - 0.1 Von V forSs2ma ~@ Fig. 1 "H" output voltage Voua 0.9Vo0 | v loneimA 2 Fig.2 Input pullup resistor ha 15 30 75 kQ | Pullup input Fig.3 Operating current. too - 10 - mA | *3 Fig.4 1 When an external clock is connected to the oscillator piri (50% duty cycle). 2 Only for CMOS output pins (1, 14, and 17). *3 All characters disptayed with fosc = 7MHz. Not designed for radiation resistance. 354 RONMMultimedia ICs BU2878FS/BU2871FS @Measurement circuits L L Voo lov Von lou i Output Output GND VoL GND Vou Set data for "L" output Set data for "H" output Fig. 1 "L" output voltage measurement circuit Fig. 2 "H" output voltage measurement circuit Voo |. los Yoo 6. 17pin Voo Input In put signal Input Output }-} GND Vin=O-~Vop GND 10, 21pin Fig. 3 Input voltage measurement circuit Fig. 4 Operating current measurement circuit @Application example . x tal 4 SYDET x" tals, -4 tot ES oO Ga ; CLK x talour 4} f _ a Microcontroller interface cs AC & 3 DATA CSYNCOUT r [+ || i. TEST CSYNCIN 33 2/6.3V 3 O$Cour DVbe 3 a OSCn PORTI DVss AVDD Geib VIDEO IN p (1e -p) VOUT SYIN AVSS VIN ROM 355 On-screen displays Muitimedia videoMultimedia ICs BU2878FS/BU2871FS a ee @External dimensions (Units: mm) 870.2 20 1 RRA ARRRR RR 2) 9 a | =| ul Bow Oo , _ FREREREREE - 1 10 o_ + - we 14 I =] 08 0.960.1 So} 24 i 0.15 SSOP - A20 356 ROAMNotes The contents described in this catalogue are correct as of March 1997. No unauthorized transmission or reproduction of this book, either in whole or in part, is permitted. . The contents of this book are subject to change without notice. Always verify before use that the contents are the latest specifications. I, by any chance, a defect should arise in the equipment as a result of use without verification of the specifications, ROHM CO., LTD., can bear no responsibility whatsoever. Application circuit diagrams and circuit constants contained in this data book are shown as examples of standard use and operation. When designing for mass production, please pay careful attention to peripheral conditions. Any and all data, including, but not limited to application circuit diagrams, information, and various data, described in this catalogue are intended only as illustrations of such devices and not as the specifications for such devices. ROHM CO., LTD., disclaims any warranty that any use of such device shall be free from infringement of any third party's intellectual property rights or other proprietary rights, and further, assumes absolutely no liability in the event of any such infringement, or arising from or connected with or related to the use of such devices. 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