Video ICs VCR Hi-Fi audio signal REC / PB amplifier with flying-erase oscillator BA7745FS The BA7745FS has the recording and playback amplifiers required for Hi-Fi VCR signal processing, and also contains a flying-erase oscillator. The recording system uses a constant-current amplifeir with AGC to eliminate the need to adjust the recording current, and ensure stable operation as the head wears. The IC also features REC MUTE and OVER REC functions . The playback system has a high-gain preamplifier, a low-offset head switch, a VCA and an EP-gain amplifier. The flying-erase oscillator has low 2nd and 3rd harmonic distortion, and when connected to an external driver large output current can be obtained. A H / L control system eliminates the need for special power supplies for the recording and playback systems. The IC has low power consumption, and comes in a compact 32-pin SSOP-P package that requires little area on the PCB. It will improve the reliability and performance of your designs while reducing external component requirements. Applications •VCRs •Features The low-noise playback amplifier has a total gain of 83dB (Typ.). Designed for VHS-bandoperation with low external parts count. It has two built-in circuits for Hi-Fi VCR operation. 2) The circuit has been designed to suppress headswitching noise. 3) Built-in EP / SP gain switching function that boosts the playback gain by 5dB. 4) Built-in VCA for easy playback output adjustment. 5) High-output recording amplifier for audio FM recording. 6) Constant-current drive provides stable recording characteristics when the load (head impedance) is fluctuating. 7) Built-in recording level AGC eliminates the need to adjust recording current. 8) Built-in low-pass filter limits the input bandwidth of the recording amplifier. 9) Built-in OVER REC recording current amplifier function and REC MUTE function that stops recording output. 10) Built-in high-frequency oscillator for use with flying erase function. 11) Record / playback switching can be done directly via the system controller, and consumes litlle power. 12) Possible to construct a high-performance audio system by pairing this chip with a Hi-Fi-audio signal processing IC. 1 Video ICs BA7745FS Power supply voltage VCC Power dissipation Pd 16 15 14 13 12 11 VCA CTRL 10 PRE OUT 9 EP / SP CTRL 8 HSWPIN 7 N.C. 6 FE LEVEL 5 N.C. VCC FE CTRL 4 VCA REC MUTE CTRL FE3 FE2 FE1 FE GND FE CTRL OVER REC CTRL 3 PB / REC EP Limits Unit PB / REC system 7.0 FE system 12.5 V 1000∗ mW Operating temperature Topr – 10 ~ + 70 °C Storage temperature Tstg – 55 ~ + 125 °C ∗ 2 Symbol REC MIX IN 2 32 •Absolute maximum ratings (Ta = 25°C) Parameter REC NF 1 31 FE OUT FE OSC 30 FE VCC N.C. N.C. REC AGC 28 VCC REC + B P 27 REC + B CH1 SW 26 REC + B CH2 BF 25 PRE AC – FB CH2 CH1 24 PRE IN CH2 CH2 23 PRE GND CH2 22 PRE IN CH1 CH1 21 PRE AC – FB CH1 P/R 20 MAIN GND PRE 19 REC OUT PRE 18 REC CURRENT SENSE R 17 REC AGC FILTER R REC / PB CTRL 29 •Block diagram When mounted on a 90mm × 50mm × 1.6mm glass epoxy board, reduced by 10mW for each increase in Ta of 1°C over 25°C. Video ICs BA7745FS •Recommended operating conditions (Ta = 25°C) Parameter Recommended operating voltage Symbol PB / REC system FE system VCCS Min. Typ. Max. 4.5 5.0 V 10.5 11.0 11.5 V Electrical characteristics •Recording system (unless otherwise noted, Ta = 25°C, V CC Parameter Symbol 〈Recording mode〉 Quiescent current Output current AGC level Output current AGC range Cross modulation distortion 0.4MHz component Cross modulation distortion 0.9MHz component 2nd-harmonic distortion 2.6MHz component Cross modulation distortion 3.0MHz component 2nd-harmonic distortion 3.4MHz component OVER REC holding voltage OVER REC holding voltage Current emphasis OVER REC MUTE holding voltage REC MUTE holding voltage Mute attenuation Iq (REC) IOAR ∆IOAR CMD04 CMD09 2HD26 CMD30 2HD34 V14L V14H IOR.OV V13L V13H IOR.MU Unit 5.5 Min. = 5V, and f = 1.7MHz) Typ. Max. Unit — 66 44.7 48.2 10 13 — – 50 — – 55 — – 47 — – 42 — – 45 0.0 — 3.5 — + 1.4 + 1.9 0.0 — 3.5 — — – 45 90 51.7 — – 43 – 40 – 40 – 35 – 40 2.2 VCC + 2.4 2.2 VCC – 40 mA mAP-P dB dB dB dB dB dB V V dB V V dB Conditions 17pin: H No signal, pin 12 + pin 29, inflow current 15pin 93.0dBµIN, 19pin OUT ∆AGC < 0.8dB, 19pin OUT 15pin MIXIN (∗), 19pin OUT (0.4MHz – 1.3MHz) 15pin MIXIN (∗), 19pin OUT (0.9MHz – 1.3MHz) 15pin MIXIN (∗), 19pin OUT (2.6MHz – 1.3MHz) 15pin MIXIN (∗), 19pin OUT (3.0MHz – 1.3MHz) 15pin MIXIN (∗), 19pin OUT (3.4MHz – 1.7MHz) When 14pin DC, NORMAL REC When 14pin DC, OVER REC 15pin 93.0dBµIN, 14pin: “H” When 13pin DC, MUTE OFF When 13pin DC, MUTE ON 15pin 93.0dBµIN, 13pin: “H” ∗ f = 1.3MHz (89.0dBµ) + 1.7MHz (97.0dBµ) (MIX) 3 Video ICs BA7745FS Playback system (unless otherwise noted, Ta = 25°C, VCC = 5V, and f = 1.5MHz) Parameter 〈Playback mode〉 Supply current Voltage gain CH1 Voltage gain CH2 Voltage gain differential Symbol Iq (PB) GVP1 GVP2 ∆GVP — 80 80 – 2.0 CH1 to CH2 crosstalk CT1→2 — – 40 – 35 dB CH2 to CH1 crosstalk CT2→1 — – 40 – 35 dB fP1 0 – 2.4 –5 dB CH1 frequency characteristic CH2 frequency characteristic Min. Typ. Max. Unit 19.0 31.0 83 86 83 86 0 + 2.0 mA dB dB dB fP2 0 – 2.4 –5 dB Gain adjustment headroom Gain adjustment headroom Maximum output voltage – ∆GVCA + ∆GVCA VOMP — +4 2.0 – 40 +6 2.6 – 30 — — dB dB VP-P CH1 input conversion noise VNP1 — 0.4 1.0 µVrms CH2 input conversion noise VNP2 — 0.4 1.0 µVrms Head switch voltage Head switch voltage Output DC offset PB holding voltage REC holding voltage Head switch-on resistance SP holding voltage EP holding voltage Gain emphasis EP VHS2 VHS1 ∆VODC V17L V17H 0.0 2.8 – 20 0.0 3.5 — — 0 — — 2.2 VCC + 20 1.0 VCC V V mV V V RSWP V9L V9H GVP. EP — 0.0 3.5 4.0 5 — — 5.0 10 2.2 VCC 6.0 Ω V V dB Design reference values •Flying erase system (unless otherwise noted, Ta = 25°C, V Parameter Symbol Min. Typ. CC Conditions 17pin: “L” 11pin: 2.0V Inflow current to pin 12 when no signal. 23pin, 20.5dBµIN, 10pin OUT, 8pin: “H” 25pin, 20.5dBµIN, 10pin OUT, 8pin: “L” 23pin, 25pin, 20.5dBµIN, ∆10pin OUT 23pin 31.0dBµ, 25pin 0 IN, 8pin: “H” → “L”, ∆10pin OUT 23pin 0, 25pin 31.0dBµIN, 8pin: “H” → “L”, ∆10pin OUT 23pin 20.5dBµIN, 8pin: “H” f = 2.2MHz / 1.0MHz, ∆10pin OUT 25pin 20.5dBµIN, 8pin: “L” f = 2.2MHz / 1.0MHz, ∆10pin OUT 11pin 2.0V→3.3V, ∆10pin OUT 11pin 2.0V→0.8V, ∆10pin OUT Pin 23 and 25 IN, pin 10 OUT 3rd-harmonic distortion, when -30dB. Input conversion for pin 23: 0.01µF + 10Ω at GND Pin 8: “H”, pin 10 OUT. Input conversion for pin 25: 0.01µF + 10Ω at GND Pin 8: “L”, pin 10 OUT. Pin 8 DC when CH2 operating Pin 8 DC when CH1 operating 23, 25pin 0 IN, 8pin: “H” → “L”, ∆10pin OUT Pin 17 DC for PB mode Pin 17 DC for REC mode Pin 20 ON resistance Pin 9 DC for SP mode Pin 9 DC for EP mode 23, 25pin 20.5dBµIN, 9pin: “H”, 10pin OUT = 11.0V) Max. Unit 〈Flying erase mode〉 Conditions 5pin: “H” Iq (FE) — 12.0 — mA Pin 2 voltage V2 — 5.5 — V 2pin DC Pin 3 voltage V3 — 5.5 — V 3pin DC Pin 6 voltage V6 — 1.0 — V 6pin DC Pin 32 voltage V32 — 4.3 — V 32pin DC Supply current Pin 31 inflow current Oscillator frequency range f32 8 — 13 MHz 32pin OUT Output amplitude range υ32 — 2.8 — VP-P 32pin OUT FE ON holding voltage V5H 4.0 — VCC V 5pin DC, When FE ON FE OFF holding voltage V5L 0 — 0.5 V 5pin DC, When FE OFF ∗ The values given above are design values, they are not ratings and are not guaranteed. 4 Video ICs BA7745FS 0.1µ 0.01µ 5V 100µ 0.01µ 390 20k 1.8k 9 HSWPIN 7 EP / SP CTRL 2.2k FE CTRL 6 N.C. PRE OUT 8 10 VCA 100µ 0.01µ 14 13 RECMUTE CTRL 12 OVERREC CTR L 11 PB / REC EP SW FE ON / OFF 5 CH2 CH1 REC MIX IN 15 REC AGC P CH1 PRE CH2 R R 22k 68p 68p 470 1 32 0.01µ 2 4.7µ 4 3 FE OSC BF 30 N.C. 31 0.01µ BF 100µ 100µ 11V 12pin SHORT FE OUT 16 P/R 20 24 25 0.1µ 29 12µ 28 27 12µ 26 560 1k 0.01µ 0.01µ 10 100p 10 100p PRE IN CH2 23 1k PRE IN CH1 PRE 560 0.1µ 22 21 680 220p 19 12 CURRENT SENSE 18 220k 0.1µ PB / REC CTRL 17 68k 0.22µ •Measurement circuit Fig. 1 mode tables •(1)Control REC / PB control Switch between REC and PB using pin 17. Control pin REC / PB Mode Function REC AMP PRE AMP REC + B SW HEAD SW (P) H REC ON OFF ON OFF L PB OFF ON OFF ON 5 Video ICs BA7745FS (2) OVER REC control Control for OVER REC (current emphasis) is done using pin 14. When in OVER REC mode, the gain setting is recording amplifier AGC level + 1.9dB. Control pin OVER REC Mode Function REC AGE Level H OVER REC 60.0mAP-P L — 48.2mAP-P (3) REC MUTE control Control for REC MUTE when recording is done using pin 13. Control pin REC MUTE Function Mode REC AMP H REC MUTE OFF L — ON (4) EP / SP control EP / SP control during playback is done using pin 9. When EP is selected, the gain of the playback amplifier is increased by 5dB over its normal setting. Control pin EP / SP 6 Mode Function PRE AMP gain H EP Typ. + 5dB L SP Typ. 8.2k 470 120p 1.5k 1 2 31 30 68p 22k 4.7µ 3 68p FE OSC BF N.C. 0.01µ 4 29 12pin SHORT 0.01µ 11V 32 100µ 100µ 5 2.2k 6 CH2 R 27 FE CTRL CH1 R 28 0.1µ 7 N.C. CH2 26 560 EP SW 9 560 100p 1.8k 10 VCA PRE 23 0.01µ 24 EP / SP CTRL 8 PRE 25 0.01µ 560 100p AUDIO HEAD 0.1µ 0.01µ 390 20k 11 5V 19 12 RECMUTE CTRL 100µ 100µ 14 20 220p OVERREC CTR L 13 0.01µ P 21 12 PB / REC CH1 22 560 680 15 P/R 17 0.1µ 0.22µ 68k 16 0.01µ REC AGC 18 220k 0.1µ CURRENT SENSE 120p 8.2k 10 11V PB / REC CTRL 1.5k 10 FE HEAD Video ICs BA7745FS •Application example REC MIX IN PRE OUT HSWPIN FE ON / OFF Fig. 2 7 Video ICs BA7745FS •External dimensions (Units: mm) 17 1 16 5.4 ± 0.2 32 0.8 0.36 ± 0.1 0.25 ± 0.1 1.9 ± 0.1 0.11 7.8 ± 0.3 13.6 ± 0.2 0.3Min. 0.15 SSOP-P32 8