Multimedia ICs Dual Voltage-controlled Amplifier BA7655A / BA7655AF The BA7655A and BA7655AF are dual voltage-controlled amplifier ICs designed for use in camcorders and VCRs. By varying the control voltage the amplifier gain can varied from -6dB to +6dB. When the control pin voltage drops below 1V the amplifier enters Power Save Mode which mutes the output and reduces the current drawn by the IC. Applications •Video cassette recorders and camcorders •1)Features Wide bandwidth. 4) Output muting possible. 5) Low voltage gain temperature drift. 2) Wide dynamic range. 3) Low power cousumption. •Block diagram VCC IN2 CTL2 OUT2 8 7 6 5 VCA2 VCA1 1 2 3 4 IN1 CTL1 OUT1 GND 1 Multimedia ICs BA7655A / BA7655AF •Pin descriptions Pin No. Function Pin name 1 IN1 2 CTL1 Input 1 Control 1 3 OUT1 Output 1 4 GND GND 5 OUT2 Output 2 6 CTL2 Control 2 7 IN2 Input 2 8 VCC Power supply •Input circuits VCC 40k 40k (Typ.) (Typ.) VCC VCC 3, 5 2.5V (Typ.) 1, 7 1m (Typ.) 2, 6 3.0V (Typ.) •Absolute maximum ratings Parameter Symbol Power supply voltage VCCMax. Power dissipation Pd Limits Unit 8.0 V 500 (BA7655A : DIP8)∗1 350 (BA7655AF : SOP8)∗2 mW Operating temperature Topr – 20 ~ + 80 °C Storage temperature Tstg – 55 ~ + 125 °C ∗1 Reduced by 5.0mW for each increase in Ta of 1°C over 25°C. ∗2 Reduce by 3.5mW for each increase in Ta of 1°C over 25°C, when mounted on a 50mm × 50mm. •Recommended operating conditions (Ta = 25°C) Parameter Power supply voltage 2 Symbol Limits Unit VCC 4.5 ~ 5.5 V Multimedia ICs BA7655A / BA7655AF •Electrical characteristics (unless otherwise noted , Ta = 25°C , V Parameter = 5.0V) Symbol Min. Typ. One channel ICC1 — 4.6 7.0 Both channels ICC2 — 7.8 12.0 2.5 2.8 — – 1.0 0.0 1.0 Minimum voltage gain GVMin. – 8.0 – 6.0 – 4.0 dB 2.0 f = 1MHz Maximum voltage gain GVMax. 8.0 dB 5.0 f = 1MHz Supply current Maximum output voltage VMax. Frequency characteristics Gf 4.0 6.0 Max. CC Unit Voltage Conditions mA 3.0 Set control voltage to 1V or less, when only one channel is used. VP-P 5.0 f = 1kHz, THD = 1% dB 3.0 f = 13MHz / 1MHz, VIN = 0.5VP-P Secondary harmonic distortion 2HD — – 40 — dB 3.0 f = 5.0M, VIN = 1VP-P Audio distortion AD — 1.0 — % 3.0 f = 1kHz, VIN = 1VP-P Muting output voltage VMUTE — — 100 mV 1.0 Set control voltage to 1 V or less ∗ ∗ VS/N — – 60 — dB 3.0 AS/N — – 60 — dB 3.0 Video S/N Audio S/N ∗ Items marked with an asterisk are rerference values. 䊊 Not designed for radiation resistance. operation •TheCircuit gain of a VCA (voltage-controlled amplifier) can be 8 varied by an external control voltage. By varying the control voltage from 2V to 5V (in the case of a 5V power supply), the gain of the amplifiers in this IC can be varied over the range -6dB to +6dB (see Figs. 1 and 2 below). When only one of the two amplifiers is being used, by setting the voltage on the CTL pin of the unused amplifier to 1V or less, it can be put into Power Save Mode. In Power Save Mode, the circuit current for the IC is cut by 40%, and the output is muted. 6 4 POWER SAVE MODE GAIN (dB) 2 0 –2 –4 –6 –8 – 10 – 12 – 14 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 Control voltage (V) Fig. 1 Voltage gain vs. control voltage characteristics IN OUT VCA CTL Voltage 2V ~ 5V Control voltage 1V or less Status Variable gain Power save Fig. 2 3 Multimedia ICs BA7655A / BA7655AF •Electrical characteristic curves 7 10.0 4.0 2.0 CONTROL VOLTAGE = 3V 0.0 – 2.0 – 4.0 CONTROL VOLTAGE = 2V – 6.0 – 8.0 – 10.0 100K 6.5 6 5.5 5 1M 10M VCC = 5V Typ. VOLTAGE GAIN (dB) CONTROL VOLTAGE = 5V VCC = 5V Max. VOLTAGE GAIN (dB) VOLTAGE GAIN : VG (dB) 6.0 1 VCC = 5V VIN = 0.5VP-P 8.0 100M FREQUENCY : ∆f (Hz) – 50 – 25 0 25 50 75 0.5 0 – 0.5 –1 100 – 50 – 25 AMBIENT TEMPERATURE : Ta (°C) Fig. 4 Maximum voltage gain vs. ambient temperature Fig. 3 Voltage gain vs. frequency 0 25 50 75 Fig. 5 Voltage gain vs. temperature –5 Min. VOLTAGE GAIN (dB) VCC = 5V – 5.5 –6 – 6.5 –7 – 50 – 25 0 25 50 75 100 AMBIENT TEMPERATURE : Ta (°C) Fig. 6 Minimum voltage gain vs. temperature •External dimensions (Units: mm) BA7655A BA7655AF 5.0 ± 0.2 1 4 0.15 ± 0.1 1.5 ± 0.1 0.11 1.27 0.4 ± 0.1 0.3Min. 0.5 ± 0.1 0° ~ 15° 0.15 DIP8 4 5 7.62 0.3 ± 0.1 2.54 8 4.4 ± 0.2 4 6.2 ± 0.3 1 6.5 ± 0.3 5 0.51Min. 3.2 ± 0.2 3.4 ± 0.3 9.3 ± 0.3 8 100 AMBIENT TEMPERATURE : Ta (°C) SOP8