BA7181FS

Video ICs 2-channel PRE / REC amplifier with auto-tracking interface BA7181FS The BA7181FS is a PRE / REC amplifier developed for use in video cassette recorders. It has been designed for use in two-head decks and features built-in FB damping, two preamplifiers, a chroma output amplifier, an FM output amplifier (with AGC), an envelope detector, a constant-current BTL-drive REC amplifier (with AGC)and built-in channel and REC / PB switches on a single monolithic IC. •Applications VCRs •Features amplifier has a total gain of 57dB 1) The playback (Typ.), and has a low-noise preamplifier. Designed for VHS-band operation with low external parts count. The IC has two circuits for two-head VCR applications. 2) Two playback output systems (through output and AGC output). The AGC output level is 300mVP-P(Typ.); suitable for FM brightness signal output. 3) Auto-tracking interface is provided for automated tracking adjustment. The detector characteristic is linear, and the sensitivity can be adjusted using external components. 4) The recording amplifier uses constant-current BLT drive that handles load variations (i.e. head impedance)well, and gives stable recording characteristics. A single circuit is provided for two-head VCR use. 5) Built-in recording level AGC means adjustment of FM recording current is not necessary. 6) Head switches for two-channel PRE / REC system provided. 7) Operates off a single 5V power supply, with low power dissipation. •Absolute maximum ratings (Ta = 25°C) Parameter Applied voltage Power dissipation Operating temperature Storage temperature Symbol VCC Pd Topr Tstg Limits 7.0 937.5∗ – 20 ~ + 65 – 55 ~ + 150 Unit V mW °C °C ∗ When mounted on a 90mm × 50mm, t = 1.6mm glass epoxy board. Reduced by 7.5mW for each increase in Ta of 1°C over 25°C. •Recommended operating (Ta = 25°C) Parameter Playback / recording (voltage range) Not designed for radiation resistance. Symbol VCC Min. 4.5 Typ. 5.0 Max. 5.5 Unit V Conditions 11pin 1 Video ICs BA7181FS •Block diagram 20 DFF IN GND 2 1 2 AGC HPF 3 – PRE 4 5 PRE 6 7 LOGIC ENVE PEAK + 8 9 10 CC = 19 DET FILTER REC LEVEL ADJ 18 REC DCFB PB AGC OUT DET PRE IN 1 (REC - OUT 1) GND 1 PRE IN 2 (REC - OUT 2) REC + OUT 17 PB AGC FILTER RF 16 15 AT ENVE PEAKING H SYNC IN – 14 13 PB RF OUT AT ENVE OUT PB / EE / REC CTRL MUTE DET REC AGC 12 REC AGC FILTER REC IN VCC 11 AT ENVE FB VCC •Electrical characteristics (unless otherwise noted, Ta = 25°C, V Parameter Symbol Min. Typ. Max. Unit 〈Playback system〉 (Fig. 1 measurement circuit, pin 8: “H” ) Quiescent current Voltage gain CH-1 Voltage gain CH-2 Iq (P) GVP1 GVP2 — 54 54 — –7 18 57 57 0 –3 45 60 60 1 0 — — — mA No signal dB dB dB dB 5.0V and f = 4.0MHz) Conditions Measurement circuit Fig.1 Fig.1 Fig.1 Fig.1 Fig.1 Fig.1 Fig.1 Fig.1 Fig.1 Pin 4 input = 0.3mVP-P, pin 1: L, pin 14 output measurement Pin 6 input = 0.3mVP-P, pin 1: H, pin 14 output measurement ∆GVP= | GVP1—GVP2 | Difference in pin 14 output level for f = 8.0 / 1.0MHz, VIN = 0.3mVP-P Voltage gain differential ∆GVP Frequency characteristic 2nd harmonic distortion∗ Maximum output level Crosstalk ∆GVf 2HDP VOMP CTP — – 45 — – 45 1.0 1.5 dBc VIN = 0.3mVP-P, 8.0MHz spurious dBc VIN = 0.3mVP-P, 12.0MHz spurious VP-P When pin 14 output 2nd harmonic distortion is –30dBc dBc Difference in pin 14 output level for pin 1: H / L 3rd harmonic distortion∗ 3HDP — – 38 – 32 ∗ Design reference values. 2 Video ICs Parameter Symbol Min. Typ. Max. Unit Conditions BA7181FS Measurement circuit 〈Playback system〉 (Fig. 1 measurement circuit, pin 8: “H” ) Output DC offset Input conversion noise∗ AGC output level AGC control sensitivity AGC amp frequency characteristic∗ PB switch ON resistance∗ ∆VODC VNIN VAGC ∆VAGC ∆G VAF RON7 — — 250 — — — 3.5 0 — 2.4 4.0 3.8 2.2 0 0 0.25 300 0.3 0.5 4 — — 0.7 2.9 4.5 — — — 150 mVP-P — µVrms 350 mVP-P 2.0 — — VCC 1.2 1.0 3.4 — VCC 2.8 1.2 dB dB Ω V V V V V V V V Pin 14 output DC offset for pin 1: H / L Rg = 10Ω, input conversion of pin 14 output noise VIN = 0.3mVP-P, pin 18 output measurement Pin 18 output difference for VIN = 0.15 ~ 0.6mVP-P Pin 18 output level difference for f = 8.0 / 1.0MHz, VIN = 0.3mVP-P Pin 7 impedance Pin 1 DC voltage for channel 2 operation Pin 1 DC voltage for channel 1 operation Pin 13 output measurement with no signal Pin 13 output measurement when pin 14 output = 400mVP-P Pin 13 output measurement for large signal Pin 8 DC voltage for PB mode Pin 8 DC voltage for REC MUTE mode Pin 8 DC voltage for REC mode Fig.1 Fig.1 Fig.1 Fig.1 Fig.1 Fig.1 Fig.1 Fig.1 Fig.1 Fig.1 Fig.1 Fig.1 Fig.1 Fig.1 PRE CH 2 threshold voltage VTH1H PRE CH 1 threshold voltage VTH1L ENVE residual voltage ENVE output level ENVE saturation voltage PB mode holding voltage EE mode holding voltage REC mode holding voltage VENV1 VENV2 VENV3 VTH10H VTH10M VTH10L Note: dBc: dB below carrier (used to express relative level from carrier reference for convenience sake). ∗ Design reference values. (unless otherwise noted, Ta = 25°C, VCC = 5.0V, f = 4.0MHz and IOAR = 30mAP-P) Parameter Symbol Min. Typ. Max. Unit Conditions Measurement circuit 〈Recording system〉 (Pin 8 in Fig. 2 measurement circuit “L” ) Supply current Recording AGC level AGC control sensitivity REC Amp frequency characteristic∗ 2nd harmonic distortion∗ 3rd harmonic distortion∗ Cross modulation distortion∗ Maximum output level Recording current load characteristic∗ Mute attenuation ratio AGC mode holding voltage AGC mode holding voltage Iq(R) IOAR ∆IOAR ∆IOAF 2HDR 3HDR CMDR IOMR ∆IORL MUR VTH15H VTH15L — 27 — — — — — 40 — — 2.7 0 72 30 0.3 – 1.5 – 45 – 50 – 50 50 – 0.35 – 45 — — 110 33 1.5 — — — — — — – 38 VCC 1.2 mAP-P mA dB dB dBc dBc dBc mAP-P dB dBc V V No signal Pin 12 input = 125mVP-P, pin 7 output measurement Pin 7 output level difference for pin 12 input = 62.5mVP-P and 250mVP-P Pin 7 output level difference for f = 8.0 / 1.0MHz, pin 12 input = 125mVP-P Pin 12 input = 125mVP-P, 8MHz spurious Pin 12 input = 125mVP-P, 12.0MHz spurious 4.0MHz ± 630kHz spurious When pin 7 output 2nd harmonic distortion is – 30dB Pin 7 output level difference for load L: 8.2 ~ 12µH Pin 7 output level difference for pin 8: M / H Pin 15 DC voltage to maintain recording AGC operation Pin 15 DC voltage to maintain recording AGC stopped Fig.2 Fig.2 Fig.2 Fig.2 Fig.2 Fig.2 Fig.2 Fig.2 Fig.2 Fig.2 Fig.2 Fig.2 ∗ Design reference values. 3 •Measurement circuits (Playback system) 4 20 1 DFF IN 470pF 43k 19 2 REC LEVEL ADJ 0.1 µ 3 18 AGC HPF PRE IN 1 1k – 0.1 µ 17 DET PRE 4 10 16 5 PB AGC OUT 0.1 µ 3.9k 22µ Video ICs 68p 10 6 PRE PRE IN 2 0.1 µ – 1k RF 7 15 H SYNC IN 390k 14 PB RF OUT PEAK Fig.1 + 8 LOGIC 0.1 µ AGC PB / EE / REC CTRL L: REC MUTE 13 ENVE L: REC START AT ENVE OUT 0.01µ 12 REC MUTE REC IN DET 9 39k 10 10k 11 VCC + Units: R [Ω] C [F] L [H] 33k AT ENVE GAIN EP “H” VCC 5V BA7181FS Video ICs (Recording system) 1 20 DFF IN 470pF 43k 19 2 REC LEVEL ADJ 0.1 µ 18 AGC HPF 3 – 0.1 µ 3.9k 22µ PB AGC OUT 17 DET PRE 4 8.2 µ 0.1 µ 16 5 68p 8.2 µ PRE 6 10 – RF 7 0.1 µ 15 390k 14 PB RF OUT PEAK H SYNC IN Fig.2 + 8 LOGIC 0.1 µ AGC REC OUT L: REC MUTE 13 ENVE L: REC START AT ENVE OUT 0.01µ 12 REC MUTE REC IN PP / EE / REC CTRL DET 9 39k 10 10k 11 + VCC Units: R [Ω] C [F] L [H] 33k AT ENVE GAIN EP “H” VCC 5V BA7181FS 5 Video ICs tables •ControlINmode 1) (1) DFF (pin • Playback input selection (head switching) Control pin DFF IN H L Function Selected playback input Channel2 (PRE IN2 7pin) Channel1 (PRE IN1 5pin) Control voltage VCTRL1 [V] 3.5 ~ V CC 0.0 ~ 1.2 BA7181FS (2) H SYNC IN (pin 15) • Controls recording AGC detector block operation. Control pin H SYNC H L Function AGC detector ON OFF Control voltage VCTRL15 [V] 2.7 ~ V CC 0.0 ~ 1.2 (3) PB / EE / REC CTRL (pin 8) • Playback / recording mute / recording mode switching Control pin PB / EE / REC H M L Mode PB REC MUTE REC Function PRE AMP ON OFF OFF AT ENVE REC MUTE REC AMP ON OFF OFF OFF ON OFF OFF ON ON Control voltage VCTRL9 [V] 3.8 ~ V CC 2.2 ~ 2.8 0.0 ~ 1.2 ∗ Pin 8 is pulled up to VCC via a 33kΩ resistor. 6 Video ICs BA7181FS REC LEVEL ADJ •Application example AT ENVE OUT PB AGC OUT PB RF OUT H SYNC IN REC Y IN REC C IN Vcc 5V 0.1 µ 22µ 68p + 20 19 18 17 3.9k 16 15 390k 14 13 0.01µ 12 43k 11 DET AGC HPF ENVE MUTE REC VCC PEAK RF AGC – PRE PRE – + DET 33k 9 10 0.1 µ 10k 39k AT ENVE GAIN EP “H” Units: R [Ω] C [F] L [H] LOGIC 1 2 3 4 5 6 7 8 470pF DFF IN 0.1 µ 0.1 µ 0.1 µ Fig.3 PB / EE / REC CTRL L:REC MUTE L:REC START HEAD A HEAD B 7 Video ICs BA7181FS •External dimensions (Units: mm) 8.7 ± 0.2 20 7.8 ± 0.3 5.4 ± 0.2 11 1 1.8 ± 0.1 10 0.11 0.8 0.36 ± 0.1 0.3Min. 0.15 SSOP-A20 8 0.15 ± 0.1