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 •1)Features The playback amplifier has a total gain of 57dB 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. (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. •Absolute maximum ratings (Ta = 25°C) Parameter Symbol Limits Unit VCC 7.0 V Pd 937.5∗ mW Applied voltage Power dissipation Operating temperature Topr – 20 ~ + 65 °C Storage temperature Tstg – 55 ~ + 150 °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 Symbol Min. Typ. Max. Unit Conditions Playback / recording (voltage range) VCC 4.5 5.0 5.5 V 11pin 䊊Not designed for radiation resistance. 1 Video ICs BA7181FS •Block diagram 20 19 18 17 PB AGC FILTER 16 AT ENVE PEAKING 15 H SYNC IN AGC PB AGC OUT HPF REC LEVEL ADJ 3 REC DCFB 2 DET FILTER 1 DFF IN GND 2 – DET PRE RF 5 GND 1 4 PRE IN 1 (REC - OUT 1) PRE 6 PRE IN 2 (REC - OUT 2) – 14 ENVE 13 AT ENVE OUT MUTE 12 REC IN VCC 11 PEAK REC AGC 10 DET 9 AT ENVE FB + REC AGC FILTER LOGIC 8 PB / EE / REC CTRL •Electrical characteristics (unless otherwise noted, Ta = 25°C, V CC = Parameter PB RF OUT VCC 7 REC + OUT 5.0V and f = 4.0MHz) Conditions Symbol Min. Typ. Max. Unit Measurement circuit 〈Playback system〉 (Fig. 1 measurement circuit, pin 8: “H” ) Quiescent current — 18 45 mA No signal Fig.1 Voltage gain CH-1 GVP1 54 57 60 dB Pin 4 input = 0.3mVP-P, pin 1: L, pin 14 output measurement Voltage gain CH-2 GVP2 54 57 60 dB Pin 6 input = 0.3mVP-P, pin 1: H, pin 14 output measurement Fig.1 Voltage gain differential ∆GVP — 0 1 dB ∆GVP= | GVP1—GVP2 | Fig.1 Frequency characteristic ∆GVf –7 – 3 0 dB Difference in pin 14 output level for f = 8.0 / 1.0MHz, VIN = 0.3mVP-P Fig.1 2nd harmonic distortion∗ Fig.1 2HDP — – 45 — dBc VIN = 0.3mVP-P, 8.0MHz spurious Fig.1 3rd harmonic distortion∗ 3HDP — – 45 — dBc VIN = 0.3mVP-P, 12.0MHz spurious Fig.1 Maximum output level VOMP 1.0 — VP-P When pin 14 output 2nd harmonic distortion is –30dBc Fig.1 Crosstalk CTP — – 38 – 32 dBc Difference in pin 14 output level for pin 1: H / L Fig.1 ∗ Design reference values. 2 Iq (P) 1.5 Video ICs Parameter BA7181FS Symbol Min. Typ. Max. Unit Conditions Measurement circuit 〈Playback system〉 (Fig. 1 measurement circuit, pin 8: “H” ) ∆VODC — 0 Input conversion noise∗ VNIN — 0.25 AGC output level VAGC 250 300 Output DC offset Pin 14 output DC offset for pin 1: H / L Fig.1 Rg = 10Ω, input conversion of pin 14 output noise Fig.1 350 mVP-P VIN = 0.3mVP-P, pin 18 output measurement Fig.1 Fig.1 Fig.1 150 mVP-P — µVrms AGC control sensitivity ∆VAGC — 0.3 2.0 dB Pin 18 output difference for VIN = 0.15 ~ 0.6mVP-P AGC amp frequency characteristic∗ ∆G VAF — 0.5 — dB Pin 18 output level difference for f = 8.0 / 1.0MHz, VIN = 0.3mVP-P PB switch ON resistance∗ RON7 — 4 — Ω Pin 7 impedance Fig.1 PRE CH 2 threshold voltage VTH1H 3.5 — VCC V Pin 1 DC voltage for channel 2 operation Fig.1 PRE CH 1 threshold voltage VTH1L 0 — 1.2 V Pin 1 DC voltage for channel 1 operation Fig.1 ENVE residual voltage — 0.7 1.0 V Pin 13 output measurement with no signal Fig.1 3.4 V Pin 13 output measurement when pin 14 output = 400mVP-P Fig.1 Fig.1 ENVE output level VENV1 VENV2 2.4 2.9 ENVE saturation voltage VENV3 4.0 4.5 — V Pin 13 output measurement for large signal PB mode holding voltage VTH10H 3.8 — VCC V Pin 8 DC voltage for PB mode Fig.1 EE mode holding voltage VTH10M 2.2 — 2.8 V Pin 8 DC voltage for REC MUTE mode Fig.1 REC mode holding voltage VTH10L 0 — 1.2 V Pin 8 DC voltage for REC mode Fig.1 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 Iq(R) — 72 110 mAP-P No signal Fig.2 Recording AGC level IOAR 27 30 33 mA Pin 12 input = 125mVP-P, pin 7 output measurement Fig.2 Fig.2 AGC control sensitivity ∆IOAR — 0.3 1.5 dB Pin 7 output level difference for pin 12 input = 62.5mVP-P and 250mVP-P REC Amp frequency characteristic∗ ∆IOAF — – 1.5 — dB Pin 7 output level difference for f = 8.0 / 1.0MHz, pin 12 input = 125mVP-P Fig.2 2nd harmonic distortion∗ 3rd harmonic distortion∗ 2HDR — – 45 — dBc Pin 12 input = 125mVP-P, 8MHz spurious Fig.2 3HDR — – 50 — dBc Pin 12 input = 125mVP-P, 12.0MHz spurious Fig.2 Cross modulation distortion∗ CMDR — – 50 — dBc 4.0MHz ± 630kHz spurious Fig.2 Maximum output level IOMR 40 50 — mAP-P When pin 7 output 2nd harmonic distortion is – 30dB Fig.2 Recording current load characteristic∗ ∆IORL — – 0.35 — dB Pin 7 output level difference for load L: 8.2 ~ 12µH Fig.2 dBc Pin 7 output level difference for pin 8: M / H Fig.2 Mute attenuation ratio MUR — – 45 – 38 AGC mode holding voltage VTH15H 2.7 — VCC V Pin 15 DC voltage to maintain recording AGC operation Fig.2 AGC mode holding voltage VTH15L 0 — 1.2 V Pin 15 DC voltage to maintain recording AGC stopped Fig.2 ∗ Design reference values. 3 Video ICs BA7181FS REC IN AT ENVE OUT PB RF OUT H SYNC IN PB AGC OUT REC LEVEL ADJ Measurement circuits •(Playback system) 20 19 18 17 16 + 0.01µ 390k 68p 22µ 3.9k 43k 0.1µ VCC 5V 15 14 DET 13 12 11 ENVE MUTE VCC REC AGC PEAK HPF RF AGC – – + PRE DET PRE 6 7 8 10 0.1µ 9 AT ENVE GAIN L: REC START 1k EP “H” PB / EE / REC CTRL L: REC MUTE 10 10 PRE IN 2 PRE IN 1 DFF IN 1k 39k 10k 5 0.1µ 4 0.1µ 3 0.1µ 2 470pF 1 33k LOGIC Units: R [Ω] C [F] L [H] Fig.1 4 LOGIC 6 7 33k DET PRE 8 9 10k 5 39k AGC 0.1µ – 14 L: REC START 4 15 PP / EE / REC CTRL 3 16 L: REC MUTE PRE 0.1µ 2 17 10 18 0.1µ 19 8.2µ 8.2µ 1 0.1µ 470pF 20 REC OUT DFF IN 0.1µ 0.01µ 390k 68p 22µ 3.9k 43k REC IN AT ENVE OUT PB RF OUT H SYNC IN PB AGC OUT REC LEVEL ADJ Video ICs BA7181FS (Recording system) VCC 5V + 13 12 11 ENVE MUTE VCC PEAK REC HPF RF AGC – + DET 10 AT ENVE GAIN EP “H” Units: R [Ω] C [F] L [H] Fig.2 5 Video ICs BA7181FS mode tables •(1)Control DFF IN (pin 1) • Playback input selection (head switching) Control pin Function DFF IN Selected playback input H Channel2 (PRE IN2 7pin) 3.5 ~ V CC L Channel1 (PRE IN1 5pin) 0.0 ~ 1.2 Control voltage VCTRL1 [V] (2) H SYNC IN (pin 15) • Controls recording AGC detector block operation. Control pin Function H SYNC AGC detector Control voltage VCTRL15 [V] H ON 2.7 ~ V CC L OFF 0.0 ~ 1.2 (3) PB / EE / REC CTRL (pin 8) • Playback / recording mute / recording mode switching Control pin PB / EE / REC Mode Function PRE AMP PB M REC MUTE OFF OFF L REC OFF OFF ∗ Pin 8 is pulled up to VCC via a 33kΩ resistor. 6 ON AT ENVE REC MUTE REC AMP H ON OFF Control voltage VCTRL9 [V] OFF 3.8 ~ V CC ON ON 2.2 ~ 2.8 OFF ON 0.0 ~ 1.2 BA7181FS PB RF OUT H SYNC IN PB AGC OUT REC LEVEL ADJ •Application example AT ENVE OUT Video ICs REC Y IN REC C IN 19 18 17 16 + 0.01µ 390k 22µ 0.1µ 3.9k 43k 20 68p Vcc 5V 15 14 DET 13 12 11 ENVE MUTE VCC REC AGC PEAK HPF RF AGC – – + PRE DET PRE 6 7 8 10 0.1µ 9 39k 10k 5 0.1µ 4 0.1µ 3 0.1µ 2 470pF 1 33k LOGIC AT ENVE GAIN L:REC START PB / EE / REC CTRL L:REC MUTE HEAD B HEAD A DFF IN EP “H” Units: R [Ω] C [F] L [H] Fig.3 7 Video ICs BA7181FS •External dimensions (Units: mm) 1 10 5.4 ± 0.2 11 0.8 0.36 ± 0.1 0.15 ± 0.1 1.8 ± 0.1 0.11 7.8 ± 0.3 8.7 ± 0.2 20 0.3Min. 0.15 SSOP-A20 8