BA7745

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 playback amplifier has a total gain of The low-noise 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 •Block diagram P/R 17 16 AGC REC 15 14 13 P 12 PB / REC 11 VCA 10 9 N.C. 8 CH2 CH2 7 6 FE CTRL 5 FE OSC BF 4 N.C. 3 2 1 CH1 EP SW PRE CH1 PRE R R REC / PB CTRL REC NF 18 REC AGC FILTER REC MIX IN 19 REC CURRENT SENSE OVER REC CTRL 20 REC OUT REC MUTE CTRL 21 MAIN GND VCC 22 PRE AC – FB CH1 VCA CTRL 23 PRE IN CH1 PRE OUT 24 PRE GND EP / SP CTRL 25 PRE IN CH2 HSWPIN 26 PRE AC – FB CH2 N.C. 27 REC + B CH2 FE LEVEL REC + B CH1 28 FE CTRL VCC REC + B 29 FE3 N.C. 30 FE2 FE VCC 31 FE1 FE OUT 32 FE GND •Absolute maximum ratings (Ta = 25°C) Parameter Power supply voltage Power dissipation Operating temperature Storage temperature Symbol VCC Pd Topr Tstg Limits PB / REC system FE system 1000∗ – 10 ~ + 70 – 55 ~ + 125 7.0 12.5 Unit V mW °C °C ∗ 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. 2 Video ICs BA7745FS •Recommended operating conditions (Ta = 25°C) Parameter Recommended operating voltage PB / REC system FE system Symbol VCCS Min. Typ. Max. 4.5 5.0 5.5 Unit V V 10.5 11.0 11.5 characteristics •Electricalsystem (unless otherwise noted, Ta = 25°C, V Recording Parameter 〈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 Symbol Iq (REC) IOAR ∆IOAR CMD04 CMD09 2HD26 CMD30 2HD34 V14L V14H IOR.OV V13L V13H IOR.MU Min. CC = 5V, and f = 1.7MHz) Max. 90 51.7 — – 43 – 40 – 40 – 35 – 40 2.2 VCC + 2.4 2.2 VCC – 40 Unit 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” Typ. — 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 ∗ f = 1.3MHz (89.0dBµ) + 1.7MHz (97.0dBµ) (MIX) 3 Video ICs 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 CH1 to CH2 crosstalk CH2 to CH1 crosstalk CH1 frequency characteristic CH2 frequency characteristic Gain adjustment headroom Gain adjustment headroom Maximum output voltage CH1 input conversion noise CH2 input conversion noise 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 Symbol Iq (PB) GVP1 GVP2 ∆GVP CT1→2 CT2→1 fP1 fP2 – ∆GVCA + ∆GVCA VOMP VNP1 VNP2 VHS2 VHS1 ∆VODC V17L V17H RSWP V9L V9H GVP. EP Min. — 80 80 – 2.0 — — 0 0 — +4 2.0 — — 0.0 2.8 – 20 0.0 3.5 — 0.0 3.5 4.0 Typ. Max. Unit mA dB dB dB dB dB dB dB dB dB VP-P µVrms µVrms V V mV V V Ω V V dB BA7745FS 19.0 31.0 83 86 83 86 0 + 2.0 – 40 – 40 – 2.4 – 2.4 – 40 +6 2.6 0.4 0.4 — — 0 — — 5 — — 5.0 – 35 – 35 –5 –5 – 30 — — 1.0 1.0 2.2 VCC + 20 1.0 VCC 10 2.2 VCC 6.0 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 •Design reference values otherwise noted, Ta = 25°C, V Flying erase system (unless Parameter 〈Flying erase mode〉 Supply current Pin 2 voltage Pin 3 voltage Pin 6 voltage Pin 32 voltage Oscillator frequency range Output amplitude range FE ON holding voltage FE OFF holding voltage Iq (FE) V2 V3 V6 V32 f32 υ32 V5H V5L — — — — — 8 — 4.0 0 12.0 5.5 5.5 1.0 4.3 — 2.8 — — Symbol Min. Typ. CC = 11.0V) Unit 5pin: “H” Conditions Max. — — — — — 13 — VCC 0.5 mA V V V V MHz VP-P V V Pin 31 inflow current 2pin DC 3pin DC 6pin DC 32pin DC 32pin OUT 32pin OUT 5pin DC, When FE ON 5pin DC, When FE OFF ∗ The values given above are design values, they are not ratings and are not guaranteed. 4 Video ICs BA7745FS 0.22µ •Measurement circuit 68k 220k 0.1µ PB / REC CTRL 12 CURRENT SENSE P/R 17 0.01µ 16 0.1µ AGC REC REC MIX IN 18 15 220p 680 OVERREC CTR L RECMUTE CTRL 5V 0.01µ PRE OUT EP / SP CTRL HSWPIN FE ON / OFF 22k 19 20 13 14 0.01µ 0.1µ 22 21 P PB / REC 560 12 PRE VCA 0.01µ 0.01µ 100p SW EP 24 100p 10 PRE IN CH2 1k PRE 25 0.1µ 560 CH2 N.C. 26 12µ CH2 27 R FE CTRL 6 7 8 9 CH1 28 12µ 12pin SHORT 29 R 4 5 FE OSC 30 N.C. 68p 2.2k 1.8k PRE IN CH1 10 23 10 1k CH1 100µ 0.01µ 100µ 11V 31 2 BF FE OUT 32 470 Fig. 1 •Control/ mode tables (1) REC PB control Switch between REC and PB using pin 17. Control pin REC / PB H L Mode REC PB Function REC AMP PRE AMP REC + B SW HEAD SW (P) ON OFF OFF ON ON OFF OFF ON 1 0.01µ 68p 4.7µ BF 3 390 20k 11 100µ 100µ 5 Video ICs (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 H L Mode OVER REC — Function REC AGE Level 60.0mAP-P 48.2mAP-P BA7745FS (3) REC MUTE control Control for REC MUTE when recording is done using pin 13. Control pin REC MUTE H L Mode REC MUTE — Function REC AMP OFF 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 H L Mode EP SP Function PRE AMP gain Typ. + 5dB Typ. 6 Video ICs FE HEAD CURRENT SENSE 11V AUDIO HEAD •Application example PB / REC CTRL 10 100µ 11V 100µ 100p 560 560 0.01µ 0.1µ 25 24 23 22 21 0.01µ 0.1µ 32 N.C. R PRE CH1 BF SW PB / REC EP CH2 CH2 PRE CH1 P R 31 30 29 28 27 26 560 220p 20 19 560 680 12 100p 10 1.5k 120p 0.01µ 470 120p 8.2k 1.5k 8.2k 220k 0.1µ 68k 12pin SHORT 18 17 0.22µ P/R AGC Fig. 2 FE OSC FE CTRL N.C. 1 0.01µ 68p 68p 4.7µ 22k 2 3 4 5 2.2k 6 7 8 HSWPIN FE ON / OFF VCA REC 9 1.8k 10 11 12 0.01µ 390 20k 13 14 15 16 0.01µ 0.1µ 100µ 100µ 0.01µ 5V PRE OUT OVERREC CTR L RECMUTE CTRL EP / SP CTRL REC MIX IN BA7745FS 7 Video ICs BA7745FS •External dimensions (Units: mm) 13.6 ± 0.2 32 7.8 ± 0.3 5.4 ± 0.2 17 1 1.9 ± 0.1 16 0.11 0.8 0.36 ± 0.1 0.3Min. 0.15 SSOP-P32 8 0.25 ± 0.1