VCR Hi-Fi audio signal REC / PB amplifier with flying-erase oscillator

Transcription

1 VC Hi-Fi audio signal EC / PB amplifier with flying-erase oscillator The has the recording and playback amplifiers required for Hi-Fi VC 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 EC MUTE and OVE EC 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 VCs 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 VC 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 OVE EC recording current amplifier function and EC MUTE function that stops recording output. 0) Built-in high-frequency oscillator for use with flying erase function. ) ecord / playback switching can be done directly via the system controller, and consumes litlle power. 2) Possible to construct a high-performance audio system by pairing this chip with a Hi-Fi-audio signal processing IC.

2 Block diagram EC / PB 7 P / 6 EC NF EC AGC FILTE 8 AGC EC 5 EC MIX IN EC CUENT SENSE 9 4 OVE EC EC OUT 20 3 EC MUTE MAIN GND 2 P 2 VCC PE AC FB CH PE IN CH PE GND PE IN CH2 PE AC FB CH PE PE CH2 CH SW PB / EC EP VCA VCA PE OUT EP / SP HSWPIN EC + B CH2 27 CH2 6 FE LEVEL EC + B CH 28 CH 5 FE FE VCC EC + B 29 4 FE3 30 BF FE OSC 3 FE2 FE VCC 3 2 FE FE OUT 32 FE GND Absolute maximum ratings (Ta = 25 C) Parameter Symbol Limits Unit Power supply voltage VCC PB / EC system 7.0 FE system 2.5 V Power dissipation Pd 000 mw Operating temperature Topr 0 ~ + 70 C Storage temperature Tstg 55 ~ + 25 C When mounted on a 90mm 50mm.6mm glass epoxy board, reduced by 0mW for each increase in Ta of C over 25 C. 2

3 ecommended operating conditions (Ta = 25 C) Parameter Symbol Min. Typ. Max. Unit ecommended operating voltage PB / EC system FE system VCCS V V Electrical characteristics ecording system (unless otherwise noted, Ta = 25 C, VCC = 5V, and f =.7MHz) Parameter Symbol Min. Typ. Max. Unit Conditions 7pin: H ecording 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 OVE EC holding voltage OVE EC holding voltage Current emphasis OVE EC MUTE holding voltage EC MUTE holding voltage Mute attenuation f =.3MHz (89.0dBµ) +.7MHz (97.0dBµ) (MIX) Iq (EC) ma No signal, pin 2 + pin 29, inflow current IOA map-p 5pin 93.0dBµIN, 9pin OUT IOA 0 3 db AGC < 0.8dB, 9pin OUT CMD db 5pin MIXIN ( ), 9pin OUT (0.4MHz.3MHz) CMD db 5pin MIXIN ( ), 9pin OUT (0.9MHz.3MHz) 2HD db 5pin MIXIN ( ), 9pin OUT (2.6MHz.3MHz) CMD db 5pin MIXIN ( ), 9pin OUT (3.0MHz.3MHz) 2HD db 5pin MIXIN ( ), 9pin OUT (3.4MHz.7MHz) V4L V When 4pin DC, NOMAL EC V4H 3.5 VCC V When 4pin DC, OVE EC IO.OV db 5pin 93.0dBµIN, 4pin: H V3L V When 3pin DC, MUTE OFF V3H 3.5 VCC V When 3pin DC, MUTE ON IO.MU db 5pin 93.0dBµIN, 3pin: H 3

4 Playback system (unless otherwise noted, Ta = 25 C, VCC = 5V, and f =.5MHz) Parameter Symbol Min. Typ. Max. Unit Conditions Playback mode Supply current Iq (PB) ma 7pin: L pin: 2.0V Inflow current to pin 2 when no signal. Voltage gain CH GVP db 23pin, 20.5dBµIN, 0pin OUT, 8pin: H Voltage gain CH2 GVP db 25pin, 20.5dBµIN, 0pin OUT, 8pin: L Voltage gain differential GVP db 23pin, 25pin, 20.5dBµIN, 0pin OUT CH to CH2 crosstalk CT db 23pin 3.0dBµ, 25pin 0 IN, 8pin: H L, 0pin OUT CH2 to CH crosstalk CT db 23pin 0, 25pin 3.0dBµIN, 8pin: H L, 0pin OUT CH frequency characteristic fp db 23pin 20.5dBµIN, 8pin: H f = 2.2MHz /.0MHz, 0pin OUT CH2 frequency characteristic fp db 25pin 20.5dBµIN, 8pin: L f = 2.2MHz /.0MHz, 0pin OUT Gain adjustment headroom Gain adjustment headroom Maximum output voltage CH input conversion noise CH2 input conversion noise Head switch voltage Head switch voltage Output DC offset PB holding voltage EC holding voltage Head switch-on resistance SP holding voltage EP holding voltage Gain emphasis EP GVCA db + GVCA db VOMP VP-P VNP µvrms VNP µvrms VHS V VHS 2.8 VCC V VODC mv V7L V V7H 3.5 VCC V SWP 5 0 Ω V9L V V9H 3.5 VCC V GVP. EP db pin 2.0V 3.3V, 0pin OUT pin 2.0V 0.8V, 0pin OUT Pin 23 and 25 IN, pin 0 OUT 3rd-harmonic distortion, when -30dB. Input conversion for pin 23: F + 0Ω at GND Pin 8: H, pin 0 OUT. Input conversion for pin 25: F + 0Ω at GND Pin 8: L, pin 0 OUT. Pin 8 DC when CH2 operating Pin 8 DC when CH operating 23, 25pin 0 IN, 8pin: H L, 0pin OUT Pin 7 DC for PB mode Pin 7 DC for EC mode Pin 20 ON resistance Pin 9 DC for SP mode Pin 9 DC for EP mode 23, 25pin 20.5dBµIN, 9pin: H, 0pin OUT Design reference values Flying erase system (unless otherwise noted, Ta = 25 C, VCC =.0V) Parameter Symbol Min. Typ. Max. Unit Conditions Flying erase mode 5pin: H Supply current Iq (FE) 2.0 ma Pin 3 inflow current Pin 2 voltage V2 5.5 V 2pin DC Pin 3 voltage V3 5.5 V 3pin DC Pin 6 voltage V6.0 V 6pin DC Pin 32 voltage V V 32pin DC Oscillator frequency range f MHz 32pin OUT Output amplitude range υ VP-P 32pin OUT FE ON holding voltage V5H 4.0 VCC V 5pin DC, When FE ON FE OFF holding voltage V5L V 5pin DC, When FE OFF The values given above are design values, they are not ratings and are not guaranteed. 4

5 Measurement circuit PE IN CH PE IN CH2 PB / EC CUENT SENSE k k 220k 00p 00p P / PE PE CH2 CH AGC P SW PB / EC EP k k 5V CH2 CH 30 BF 0 FE OSC 68k p 0.22µ VCA FE 2.2k 2µ BF V EC 2µ EC MIX IN OVEEC CT L ECMUTE PE OUT EP / SP HSWPIN FE ON / OFF 2pin SHOT 3 68p 68p 4.7µ 22k FE OUT 32 Fig. Control mode tables () EC / PB control Switch between EC and PB using pin 7. Control pin Function Mode EC / PB EC AMP PE AMP EC + B SW HEAD SW (P) H EC ON OFF ON OFF L PB OFF ON OFF ON 5

6 (2) OVE EC control Control for OVE EC (current emphasis) is done using pin 4. When in OVE EC mode, the gain setting is recording amplifier AGC level +.9dB. Control pin Mode OVE EC H OVE EC L Function EC AGE Level 60.0mAP-P 48.2mAP-P (3) EC MUTE control Control for EC MUTE when recording is done using pin 3. Control pin EC MUTE Mode Function EC AMP H EC 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 Function Mode EP / SP PE AMP gain H EP Typ. + 5dB L SP Typ. 6

7 Application example PB / EC CUENT SENSE 220k k 220p 0.22µ P / P AGC EC EC MIX IN OVEEC CT L ECMUTE FE HEAD 0.5k 20p 8.2k AUDIO HEAD 8.2k 0.5k 00p 00p 20p PE PE CH2 CH SW PB / EC EP k k VCA V PE OUT EP / SP HSWPIN CH2 CH 5 FE 2.2k FE ON / OFF 2pin SHOT 4 V BF FE OSC V 68p 68p 4.7µ 22k Fig. 2 7

8 External dimensions (Units: mm) 3.6 ± ± ± ± ± Min ± SSOP-P32 8