BA7797F

Video ICs VCR standard audio signal processor BA7797F The BA7797F is standard audio signal processor designed for use in VCRs and tape decks. The circuit is comprised of a playback preamplifier, a line amplifier, a recording amplifier, an ALC circuit and high-voltage head switch. The IC has a built-in coil equivalent circuit for recording equalization, which eliminates the need for an external component. •Applications recorders and tape decks Video cassette •Features switching systems built-in (LINE and TUN1) Two input ER). 2) Built-in coil equivalent circuit for recording equalization. 3) High-performance low-noise playback amplifier. 4) ALC level can be adjusted by connection of an external resistor. 5) Compatible with single-mode EQ making it ideally suited to widely-used decks. •Block diagram PB IN 1 REC 18 GND REC REC HEAD SW 2 17 PB PB NFB REC OUT 3 REC AMP EQ + 28dB LINE 16 PB OUT REC L 4 0dB 15 PB LINE IN VCC 5 ALC 14 ALC FILTER RIPPLE FILTER 6 ATT – 8dB 13 TUNER IN REC / EE CTRL 7 MUTE 12 PB / TU / LINE CTRL BUFF LINE OUT 8 ATT – 8dB 11 LINE IN ALC LEVEL ADJ 9 10 MUTE CTRL 1 Video ICs BA7797F •Absolute maximum ratings (Ta = 25°C) Parameter Power supply voltage Power dissipation Operating temperature Storage temperature each increase in Ta of 1°C over 25°C. Symbol VCC Pd Topr Tstg Limits 13 550∗ – 10 ~ + 65 – 55 ~ + 125 Unit V mW °C °C ∗ When mounted on a 50mm × 50mm × 1.6mm glass epoxy board. Reduced by 5.5mW for •Recommended operating conditions (Ta = 25°C) Parameter Power supply voltage Symbol VCC Min. 7.5 Typ. — Max. 12.5 Unit V •Pin descriptions (V Pin No. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 CC = 10V) Function Playback amplifier input / playback head switch High-withstanding voltage recording head switch Recording amplifier output Recording EQ switch VCC Ripple filter REC / EE control Line amplifier output ALC level adjustment Mute control Line input PB / TU / LINE control Tuner input For setting the time constant for the ALC filter (attack and recovery times) Line input for playback Playback amplifier output Playback amplifier feedback GND Pin voltage 2.0V 0.0V 4.7V 4.7V 10.0V 10.0V — 4.7V 4.1V — 4.7V — 4.7V PB: 0.0V PB: Not fixed 4.7V 2.0V 2.0V 0.0V I / O circuit REC: 120kΩ REC: 11Ω REC: 17Ω (ON) REC: OPEN EF (P-P) B (NPN) — 10kΩ (VCC) See input / output circuit EF (P-P) See Fig. 4 See input / output circuit 120kΩ See input / output circuit 120kΩ EF (NPN) ~ 100Ω 120kΩ EF (P-P) B (NPN) — Pin name PB IN REC HEAD SW REC OUT REC L VCC RIPPLE FILTER REC / EE CTRL LINE OUT ALC LEVEL ADJ MUTE CTRL LINE IN PB / TU / LINE CTRL TUNER IN ALC FILTER PB LINE IN PB OUT PB NFB GND ∗ EF: emitter follower, P-P: push pull, B: base, and C: collector. All measurements made using the measurement circuit (Fig.1) with VCC = 10V and quiescent circuit conditions. All numerical values are standardized values. 2 Video ICs BA7797F •Input / output circuits REC / EE CTRL 7 REC / EE CTRL 7 56kΩ H L MUTE CTRL 10 MUTE CTRL 10 56kΩ M REC AMP PB HEAD SW PB / TU / LINE CTRL 12 H L PB / TU / LINE CTRL 56kΩ 12 3 Video ICs BA7797F CC •Electrical characteristics (unless otherwise noted, Ta = 25°C, V Parameter Quiescent current EE Quiescent current PB Quiescent current REC 〈Line amplifier〉 Voltage gain (PB input) Voltage gain (LINE1, LINE2, TU inputs) Distortion Maximum output level Output residual noise ALC level ALC distortion Mute attenuation ratio 〈Recording amplifier〉 Voltage gain Distortion Maximum output level Openloop gain Playback preamplifier Openloop gain Input conversion noise Voltage gain (stand alone) 〈Head switch〉 PB head switch impedance REC head switch impedance RPH RRH — — — 80 11 17 0 100 20 25 10 — GVOP VNINP GVCP 61 — 35.0 68 36.0 — 37.0 GVCR THDR VOMR GVOR 19.0 — 5.7 60 20.0 0.13 8.2 71 21.0 0.4 — — GVCLP GVCLT THDLT VOMLT VNOLT VOA THDA MT 27.0 19.0 — 5.9 — – 9.0 — — 28.0 20.0 0.1 8.4 – 81.5 – 8.0 0.1 – 82.0 29.0 21.0 0.3 — – 75 – 7.0 0.5 – 72 Symbol IqEE IqPB IqREC Min. 6.4 6.4 5.2 Typ. 8.5 8.5 6.9 11.3 11.3 9.2 = 10V, and f = 1kHz) Unit mA mA mA dB dB % dBV dBV dBV % dB dB % dBV dB dB dBV dB Ω Ω µA VP-P E2 = ± 55V f = 70kHz, V2 ± 1.5V Rg = 680Ω, DIN AUDIO PB IN→PB OUT Conditions No signal No signal No signal VO = – 8dBV VO = – 8dBV VO = – 8dBV, RL = 4.7kΩ∗ THD = 1%, RL = 4.7kΩ∗ Rg = 4.7kΩ, DIN AUDIO VIN = – 25dBV, 9pin: OPEN VIN = – 25dBV, RL = 4.7kΩ∗ VO = 0dBV, DIN AUDIO LINE IN, TUNER IN→REC OUT VO = – 8dBV VO = – 8dBV, RL = 4.7kΩ∗ THD = 1%, RL = 4.7kΩ∗ Measurement circuit Max. 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 Fig.1 Fig.1 Fig.1 Fig.1 Fig.1 Fig.1 Fig.1 Fig.2 – 122.5 – 114 REC head switch DC withstanding voltage BVRHDC REC head switch AC withstanding voltage BVRHAC ∗ Measured at BW = 400Hz to 30kHz. 4 Video ICs BA7797F •Measurement circuits 3.3µ PB IN REC HEAD SW 4.7µ REC OUT 1 REC 68k ON: Gvo PB 18 330 22µ 0.01µ + + 680 REC 2 17 PB 12k 330k + PB OUT 4.7k 1800p 1.5k 6000p 3 REC AMP EQ 0dB 12k + 28dB LINE 16 0.1µ 4.7k 47k + + 4.7µ 22µ 2.2M 4.7k 4 15 PB LINE IN VCC 33µ 22µ + 5 ALC 6 ATT – 8dB 14 0.1µ ON: ALC OFF 13 4.7k 47k TUNER IN + MUTE REC / EE CTRL 4.7µ LINE OUT 7 BUFF 12 0.1µ PB / TU / LINE CTRL 4.7k LINE IN 47k 8 ATT – 8dB 11 + 4.7k 9 10 MUTE CTRL Fig.1 Units: R [Ω] C [F] 1 PB IN SW2 3 0.1µ V ~ BVRHAC 100k 100k 1k e2 V2 V 0.1µ REC head switch AC withstanding voltage measurement circuit Fig. 2 REC REC OUT 2 5 Video ICs BA7797F •Control mode table (1) REC / EE control, PB / TU / LINE control Control pins REC / EE L L L H H H PB / TU / LINE L M H L M H Mode LINE TUNER PB LINE REC TU REC inhibit Function PB HSW OFF OFF OFF ON ON — REC HSW ON ON ON OFF OFF — LINE SW LINE TUNER PB LINE TUNER — REC AMP OFF OFF OFF ON ON — If REC / EE CTRL is set to "M", the REC pause state is possible (REC head switch: open, REC amplifier: off). (2) Mute control Control pins MUTE H L MUTE MUTE Mode Function LINE SW OPEN CLOSE •Application example 3.3µ REC + B 330 REC 2 17 3 REC AMP EQ 0dB + 28dB LINE 16 EQ CTRL 4 15 0.1µ 8.2k 12k 0.01µ EQ CTRL TUNER IN LINE IN VCC 5 14 33µ 6 ATT – 8dB 13 MUTE REC / EE CTRL LINE OUT RL 7 0.1µ 22µ ALC + + 12 BUFF 8 ATT – 8dB 11 9 ALC LEVEL ADJ 0.1µ 10 Units: R [Ω] C [F] Fig.3 6 330k PB PB / TU / LINE CTRL MUTE CTRL 22µ + BIAS OSC 1 REC 18 + + + + Video ICs BA7797F •Operation notes (1) ALC level Set the ALC level in the range – 8dBV to 0dBV by connecting a resistor between pin 9 and GND. VBIAS VOA = = 1 2 1 2 4k VCC – 0.7 • 4k + 32k × R / (32k + R) 2 4k • • VBIAS 4k + 32k × R / (32k + R) • ALC LEVEL ADJ 9 R 4k ALC DET 32k The formula for approximating the value of this resistor is as follows: When pin 9 is open, VOA is preset to – 8dBV (for VCC = 10V). Note that the supply voltage VCC has an effect. Fig.4 VBIAS = VCC – 0.7 2 9pin Voltage = 32k × R / (32k + R) • VBIAS 4k + 32k × R / (32k + R) (2) Mute signal Apply the mute signal shown below at power on and off. If the muting time is short, a “pop” sound will be audible, particularly when the power is switched on. VCC (H) (H) MUTE CTRL 2 sec. Min. LINE OUT Fig.5 Also, be certain to apply the mute signal when switching between PB / LINE / TU. In the case of LINE / TU switching, it is possible to suppress switching noise by applying a time constant to the signal, in which case it is not necessary to apply the mute signal. (3) Recording control Do not switch the PB and REC modes on together. This will cause faulty operation. (4) Line output The line output can drive a load resistance of up to 2kΩ. Depending on the type of load, it can cause local oscillation (eg. large capacitive loads that draw large current), so caution is required. In particular, when there is a possibility that the line output will be connected to a shielded cable, or line cable, connect a resistor of about 1kΩ in series with the output so that the capacitive load is not directly coupled to the IC output terminal. 7 Video ICs BA7797F •Electrical characteristic curves 60 VCC = 10V VIN = – 60dBV 50 + – PB 10 MAXIMUM OUTPUT LEVEL: Vom (dBV) 10 f = 1kHz Input: LINE IN Output: LINE OUT 00 VCC = 10V – 10 VCC = 8.58V GAIN: GV (dB) 17 40 22µ 330 + 330k 0.01µ 16 12k 6 VCC = 10V THD = 1% (BW = 0.4 ~ 30kHz) ALC OFF LINE + 4 30 2 10µ VOUT RL OUTPUT LEVEL: VOUT (dBV) 8 20 – 20 0 10 100 1k 10k 100k 1M 10M 100 200 500 1k 2k 5k 10k – 30 – 40 – 30 – 20 – 10 00 FREQUENCY: f (Hz) LOAD RESISTANCE: RL (Ω) INPUT LEVEL: VIN (dBV) Fig. 6 Gain vs. frequency (PB amplifier) Fig. 7 Line amplifier load drive characteristics Fig. 8 ALC input / output characteristics 50 REC &EQ 4 12k 3 40 GAIN GVR: (dB) VCC = 10V Input: LINE IN Output: REC OUT OUT 1800p 6000p + 1.5k 10µ 4.7k 30 20 10 100 1k 10k 100k FREQUENCY: f (Hz) Fig. 9 Gain vs. frequency (REC amplifier) •External dimensions (Units: mm) 11.2 ± 0.2 18 7.8 ± 0.3 5.4 ± 0.2 10 1 1.8 ± 0.1 9 0.11 1.27 0.4 ± 0.1 0.3Min. 0.15 SOP18 8 0.15 ± 0.1