A840

Video ICs CTL recording / playback amplifier for VHS VCRs BA8400FV The BA8400FV is a CTL recording / playback amplifier developed for VHS VCRs. The playback amplifier has an AGC circuit that can handle large input signal fluctuations, and a recording / playback switching circuit is provided to allow high-speed switching. •Applications VHS-format VCRs •Featuresoperated off low power supply voltage (2.7V 1) Can be to 3.5V). 2) Playback amplifier with AGC. 3) Fast switching between recording and playback. •Block diagram MONI OUT HysBIAS FILTER 14 13 12 11 10 9 8 P RECPBGND 7 Ref R CTL – 6 BIAS AGC IN – AMP CTL + 5 P VCC DET REC AMP R P 1 2 SW 3 CTL OUT RECHPB RECIN GND 4 R AGC 1 Video ICs BA8400FV •Pin descriptions Pin No. 1 Pin name CTL OUT (CTL pulse output) RECHPB (record / play switch) RECIN (REC CTL pulse input) GND CTL + (CTL head “+” input) CTL – (CTL head “–” input) RECPBGND BIAS (bias) IN – (playback amplifier input) Function CTL pulse output. High output level approx. VCC – 0.05V, IO = + 0.5mA Low output level approx. 0.05V, IO = – 0.5mA Switch input pin for the record / playback amplifiers. High input: REC mode Low input: PB mode Threshold voltage: approx. 1 / 2VCC CTL pulse input pin for recording. Threshold voltage: approx. 1 / 2VCC Power, REC / PB SW, CTL output buffer ground pin. When recording: CTL head positive-side recording current. When playing: input pin for the playback CTL pulse. When recording: CTL head negative-side recording current. When playing: bias pin for the playback CTL pulse input. Ground pin for the REC and playback amplifiers. Bias pin for the playback amplifier. Bias voltage: VIB8 = 0.15VCC + 1.3V (approx.) Feedback input pin for the playback amplifier. 2 3 4 5 6 7 8 9 10 MONIOUT Playback amplifier output monitor pin. (playback amplifier output) Output dynamic range is the DC level ± Vf. AGC (AGC time constant) HysBIAS (hysteresis amplifier center level) FILTER (high-frequency noise filter) VCC Set the time constant after considering the transient response of the playback mode switching. AGC detect level VdetAGC = 0.47VCC [V] (approx.) Playback amplifier output amplitude VAGC = 2 × (VdetAGC – HysVcent) [VP-P] Connection pin for the bypass capacitor for the hysteresis amplifier center level. Pin for connection of high-frequency noise filter for AGC amplifier output for playback CTL pulse. Also, input pin for the hysteresis amplifier. Hysteresis amplifier center voltage HysVcent = 0.27Vcc [V] approx. High-side hysteresis width ∆HysVH = 0.367VCC – HysVcent [V] Low-side hysteresis width ∆HysVL = 0.173VCC – HysVcent [V] Connect a decoupling capacitor close to the pin. 11 12 13 14 •Absolute maximum ratings (Ta = 25°C) Parameter Power supply voltage Power dissipation Operating temperature Storage temperature Symbol VCC Pd Topr Tstg Limits 8.0 450∗ – 25 ~ + 75 – 55 ~ + 125 Unit V mW °C °C •Recommended operating conditions (Ta = 25°C) Parameter Symbol VCC Applied voltage Not designed for radiation resistance. ∗ Reduced by 4.5mW for each increase in Ta of 1 °C over 25°C. Limits Unit V 2.7 ~ 3.5 2 Video ICs BA8400FV •Input / output circuits Vcc Vcc 25k Vcc 1 CTLOUT 1k 2 30k RECPB 25k Fig.1 Vcc Fig.2 Vcc 25k CTL + 5 3 30k RECIN 6 CTL – 2k 25k Fig.3 Fig.4 Vcc 22k BIAS 8 45k 30k 4k Fig.5 3 Video ICs CTL + 5 Vcc BA8400FV 22k 45k 30k 2k 4k 1.7V 1.7V 9 IN – 100 100 10 Fig.6 Vcc MONIOUT 15.9k 14.1k 5.6k 1k 11 AGC Vcc Fig.7 19k 2.9k 2.9k 5.2k 13 FILTER 12 HysBIAS Fig.8 4 Video ICs BA8400FV CC •Electrical characteristics (unless otherwise noted, Ta = 25°C and V Parameter Circuit current 〈AGC amplifier〉 AGC amplifier gain Input bias voltage Pin 5 input resistance AGC control sensitivity Output amplitude 〈Hysteresis amplifier〉 Hysteresis width CTLOUT output high level voltage CTLOUT output low level voltage 〈REC amplifier〉 Recording current Max. output high level voltage Max. output low level voltage Threshold voltage Input resistance 〈REC / PB switch〉 Threshold voltage REC to PB switching time Vth2 TR – P 1.0 — 1.5 — Irec VOHR VOLR Vth3 ZIN3 ± 1.3 2.0 — 1.0 24 ± 2.5 2.8 0.2 1.5 30 ∆HysV VOHP VOLP ± 250 2.0 — ± 290 2.8 0.2 GVagc VIB8 ZIN5 ∆AGC / V VAGC 2.5 1.35 1.6 –2 0.88 4.5 1.7 2.0 0 1.1 Symbol ICC Min. — Typ. 3.5 = 3V) Unit mA Conditions No signal, CTLOUT: High Max. 7.0 6.5 2.05 2.4 +2 1.32 ± 330 — 1.0 ± 3.7 — 1.0 2.0 36 dB V kΩ dB VP-P — — — VIN = 0.15→1.0VP-P f = 300Hz, VIN = 300mVP-P mV V V IO = – 0.5mA IO = + 0.5mA — mA V V V kΩ RO = 400 W IO = – 0.5mA IO = + 0.5mA — — 2.0 100 V ms ∗See note below — ∗ Note: The switching time from REC to PB is the time until CTLOUT is output. 5 Video ICs BA8400FV •Measurement circuit SW1 a b c 1 Is1 V Vm1 P R 14 VCC A Am14 SW13a 2 A Am2 SW2 a b c 3 V Is2 VCC a b c V Vm3 Vs3 VCC 5 SW5 a b c + SW 13 V 1000p + – 12 REC AMP + – + SW13b Vm13 270k Vs13 A Am3 SW3 d 4 4.7k SW12 DET 11 1µ + 10µ 1M V R AGC 10 P 400 A Am56 10µ 6 P V Vm6 a 7 Ref 8 910 V Vm5 R AMP + – 9 a 330k b SW10 V Vm10 12k Is5 OSC 820 b SW9 + + V Vm8 1µ 10µ Fig.9 6 Video ICs BA8400FV CC •Measurement conditions (unless otherwise noted, Ta = 25°C and V Parameter Circuit current 〈AGC amplifier〉 AGC amplifier gain Input bias voltage Pin 5 input resistance AGC control sensitivity Output amplitude 〈Hysteresis amplifier〉 Hysteresis width CTLOUT output voltage H CTLOUT output voltage L 〈REC amplifier〉 Recording current 5 Recording current 6 Max. output voltage "H" Max. output voltage "L" Input threshold voltage Input resistance 〈REC / PB switch〉 Threshold voltage REC to PB switching time Measurement method = 3V) Notes — ∗1. f = 300Hz, Switch position Symbol ICC Monitor SW 1 Am14 a SW SW SW 2 3 5 a a a SW SW SW SW SW 9 10 12 13a 13b a a ON OFF OFF GVagc VIB8 ZIN5 ∆AGC / V VAGC Vm13 Vm8 Vm5 13pin 13pin a a a a a a a b a a a a b a a c a b c c b a a a a b a a b b OFF ON OFF ON OFF OFF ON OFF OFF ON OFF OFF ON OFF OFF VIN = 50mVP-P — ∗2. ∗3. f = 300Hz, VIN = 0.15 / 1.0VP-P ∗4. f = 300Hz, VIN = 300mVP-P ∗5. ∆HysV VOHP VOLP Vm1 Vm1 Vm1 a c c a a a a a a a a a a a a a a a ON OFF ON OFF ON OFF b b b IO = – 0.5mA, Vs13 = 1.5V IO = + 0.5mA, Vs13 = 0V Irec5 Irec6 VOHR VOLR Vth3 ZIN3 Am56 Am56 Vm1 Vm1 Vm3 Vm3 a a c c a a b b b b b b b a b a c d a a a a a a a a a a a a a a a a a a ON OFF OFF ON OFF OFF ON OFF OFF ON OFF OFF ON OFF OFF ON OFF OFF ∗6. — — IO = – 0.5mA IO = + 0.5mA — Vth2 TR-P Vm2 1pin a a c ba a a a c a a a a ON OFF OFF ON OFF OFF ∗6. — ∗1 Input a sine wave of f = 300Hz to pin 5, and measure the output amplitudes on pins 10 and 13 (Vo10 and Vo13). The AGC gain is given by: Gvagc = 20log (Vo13 / Vo10) [dB]. ∗2 Measure the output voltages Vo0 and Vo.5 on pin 5 when currents of Is5 = 0, and Is5 = 0.5mA are applied. The input resistance is given by: ZIN5 = {0.0005 / (Vo.5 Vo0) 1 / 400} –1 [Ω] ∗3 Input a sine wave of f = 300Hz to pin 5. Adjust the input level until the output amplitude on pin 10 is 0.15VP-P and 1.0VP-P, and measure the corresponding output amplitudes on pin 13 (Vo0.15 and Vo1.0). The AGC control sensitivity is given by: ∆AGC / V = 20log (Vo1.0 / Vo0.15) [dB]. ∗4 Input a sine wave of f = 300Hz to pin 5. Adjust the input level until the output amplitude on pin 10 is 300mVP-P. Measure the output amplitude on pin 13. ∗5 With pin 13 floating, measure the output voltage Vocent. Increase Vs13 from 0V, and record VINH as the Vs13 voltage when the pin 1 output exceeds 2.8V. Decrease Vs13 from 1.5V, and record VINL as the Vs13 voltage when the pin 1 output goes below 0.2V. High-side hysteresis width ∆HysVH = VINH Vocent [VP-P] Low-side hysteresis width ∆HysVL = VINL Vocent [VP-P] ∗6 Measure the currents IIN2.7 and IIN3.0 on pin 3 when voltages Vs3 of 2.7V and 3.0V respectively are applied. The input resistance is given by: ZIN3 = 0.3 / (IIN3.0 IIN2.7) [Ω] ∗7 Input a square wave of 300Hz, VIN = 20mVP-P to pin 5, and measure the time that it takes CTLOUT to be output after pin 2 goes from VCC to 0V. 7 Video ICs BA8400FV •Application example VCC 3.0V CTL OUT 1 P R 14 + 33µF RECHPB 2 SW 13 FILTER 1000pF RECIN + 3 – 12 + HysBIAS REC AMP + – 22µF GND 4 DET 11 1µF + AGC 1MΩ AGC R CTL + 5 P 10 MONI OUT AMP + – R 330kΩ IN – 6 CTL – P 9 910Ω + 10µF RECPBGND 7 Ref 8 + BIAS 1µF Fig.10 8 Video ICs BA8400FV •External dimensions (Units: mm) 5.0 ± 0.2 14 6.4 ± 0.3 4.4 ± 0.2 8 1.15 ± 0.1 1 0.1 7 0.65 0.22 ± 0.1 0.3Min. 0.1 SSOP-B14 0.15 ± 0.1 9