Video ICs Digital servo controller for VCRs BU2890 series The BU2890 series are LSI linear digital-servo controllers that allows construction of a VCR servo system using one IC. The package is a SDIP 42 pin. The circuit provides linear input signal wave-shaping, and has a servo function for output of the speed and phase control for the drum and capstan. In addition, it generates a quasi-V pulse for special playback, and has a recording mode auto-discrimination function, an FM audio head switch signal generator for Hi-Fi systems, and is compatible with VISS / VASS operation. It can also steplessly vary capstan speed during FF / REW. It also has a mixing amplifier and CTL amplifier for linear signal wave-shaping, so external linear circuits are not required. Applications •VCRs •1)Features All VCR servo functions on a single chip. 2) Built-in CTL and mixing amplifiers with AGC. 3) Built-in wave-shaping circuit for the DFG, DPG and CFG signals. 4) Mode setting via two-line serial data transfer with parity checking. 5) Built-in digital gain-compensation circuit for the capstan system. 6) VISS / VASS compatible with CTL overwrite for playback and VISS code discrimination. 7) Microprocessor control for stepless capstan speed control during FF and REW. 8) Special constant-voltage diode for playback head switching logic. •Recommended operating conditions (Ta = 25°C) Parameter Power supply voltage Symbol Limits Unit VDD 4.5 ~ 5.5 V •Absolute maximum ratings (Ta = 25°C) Parameter Symbol Limits Unit Power supply voltage VDD 7 V Power dissipation Pd 500∗ mW Operating temperature Topr – 15 ~ + 70 °C Storage temperature Tstg – 55 ~ + 125 °C VIN VSS – 0.3 ~ VDD + 0.3 V Pin applied voltage ∗ Reduced by 5mW for each increase in Ta of 1°C over 25°C. 1 Video ICs BU2890 series •Block diagram H. A. SW DPV OUT 3 VDD 4 CFV OUT VSS ROM DRUM F-V REC ROM CAP F-V 42 ENV 41 SLOW + STILL 40 DRUM MIX + 39 DRUM MIX – 38 DRUM MIXOUT 37 CAPMIX + 36 CAPMIX – 35 CAP MIXOUT 34 DPGIN 33 DFGIN 32 CFGIN 31 CFGAMPOUT 30 CTLAMPOUT DRUMMIX ROM CAP REF 5 6 DIGITAL TRACKING ROM REF GENER DRUM PHASE 2 DFV OUT CPV OUT HEADSW LOGIC 1 REC CAP PHASE 7 CAPMIX FSCIN 8 PORT1OUT 9 CLK GENER DFG COUNT 1/N ROTARY 10 REC SDATA 11 1/M MODE CTL SCLOCK 12 SWMM 13 CLAMP 1/N RFSW MM AGC CTLF 14 RF-SW AF-SW 29 CTLAMP – 28 VSSA 27 VDDA 26 RECCTL + 25 RECCTL – CTLR GENER AHSW 15 CSYNCIN 16 F V-SYNC SEP REC H SEP VPOUT 17 REC VD GENER REC CTL 18 FF REC DA REC CFGOUT CTLOUT 20 21 2 1/2 19 1/2 REC SLOW 24 AMP BIAS TAPE SPEED DET. 23 EP / LP / SP DUTY VISS DET 22 CTLDUTYOUT Video ICs BU2890 series •Pin descriptions Pin No. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 Pin name H. A. SW DPVOUT DFVOUT VDD CPVOUT CFVOUT VSS FSCIN PORT1OUT ROTARY SDATA SCLOCK SWMM RFSW AHSW CSYNCIN VPOUT CFGOUT CTLOUT CTLDUTYOUT EP / LP / SP AMPBIAS RECCTL – RECCTL + VDDA VSSA CTLAMP – CTLAMPOUT CFGAMPOUT CFGIN DFGIN DPGIN CAPMIXOUT CAPMIX – CAPMIX + DRUMMIXOUT DRUMMIX – DRUMMIX + SLOW + STILL ENV Function Head amplifier switch output Drum phase error PWM output Drum speed error PWM output Logic power supply Capstan phase error PWM output Capstan speed error PWM output Logic ground fsc input Serial port 1 output Chroma rotary output Serial data input Serial clock input SW monostable multivibrator Video head switch output Audio head switch output Composite synchronization input Quasi-Vpulse output Optional pin CFG wave shaping output CTL wave shaping output Optional pin CTL duty discriminant output / VISS discriminant output Tape speed discriminator output Amplifier bias voltage output CTL coil ( – ) CTL coil ( + ) Analog power supply Analog ground CTL amplifier ( – ) input CTL amplifier output CFG amplifier output CFG amplifier input DFG amplifier input DPG amplifier input Capstan MIX amplifier output Capstan MIX amplifier ( – ) input Capstan MIX amplifier ( + ) input Drum MIX amplifier output Drum MIX amplifier ( – ) input Drum MIX amplifier ( + ) input Slow / still input Envelope detector input 3 Video ICs BU2890 series •Electrical characteristics (unless otherwise noted, Ta = 25°C and V Parameter DD = 5V) Symbol Min. Typ. Max. Unit Supply current IDD 17 33 60 mA Conditions Logic output high level voltage VH 4.0 4.7 — V ILOAD = –1.0mA Logic output low level voltage VL — 0.2 0.5 V ILOAD = 1.0mA Logic input threshold VTH 1.5 — 3.5 V Three-value input H / M threshold VTH1 2.85 3.30 4.00 V Three-value input M / L threshold VTH2 0.80 1.25 1.75 V fsc input level Vfsc 0.2 — 3.0 VP-P Monostable multivibrator comparator level VTHM 2.15 2.40 2.65 V RECCTL output high level voltage VCTH 2.9 3.2 — V IL = – 3.0mA RECCTL output low level voltage VCTL — 0.3 0.5 V IL = 3.0mA DFG input sensitivity VDFG 0.1 0.2 0.4 mVP-P DPG input sensitivity VDPG 30 50 70 mVO-P CFG amplifier openloop gain GCFG 70 CFG input threshold VTCF ± 120 MIX amplifier openloop gain GMIX 60 — — dB MIX amplifier output high level voltage VOH 4.2 4.7 — V ILOAD = – 5.0mA ILOAD = 5.0mA — ± 150 — ± 180 dB mVP-P MIX amplifier output low level voltage VOL — 0.4 0.6 V MIX amplifier bias voltage VBMI 2.4 2.5 2.6 V 4 AC coupling Video ICs BU2890 series •External dimensions (Units: mm) 37.1 ± 0.3 22 0.51Min. 3.2 ± 0.3 4.5 ± 0.3 13.7 ± 0.3 42 1 21 15.2 0.3 ± 0.1 0° ~ 15° 0.5 ± 0.1 1.778 SDIP42 5