Video ICs Stereo zoom microphone amplifier for camcorders BA7780KV The BA7780KV is a microphone amplifier developed for use in camcorders. The IC features an electronic volume circuit for presetting the curve required for the stereo zoom function, a microphone element power supply regulator, a wind-noise rejection filter, a current limiting circuit for external accessory power supplies, and an input for external microphone input. The IC operates off a 3.3V power supply. Applications •Camcorders •1)Features Operates off a 3.0V to 5.25V power supply. 4) Adjustable microphone element sensitivity. 5) Matrix amplifier for stereo emphasis. 6) Automatic switching circuit for external inputs, and built-in external monaural decision circuit. 2) Zoom microphone processing function on one chip. 3) Built-in electronic volume for external setting of sensitivity and control voltage. •Absolute maximum ratings (Ta = 25°C) Parameter Symbol Limits Unit VCC 7.0 V mW Power supply voltage Pd 750∗ Operating temperature Topr – 10 ~ + 70 °C Storage temperature Tstg – 55 ~ + 125 °C Power dissipation ∗ Reduced by 7.5mW for each increase in Ta of 1°C over 25°C. •Recommended operating conditions (Ta = 25°C) Parameter Power supply voltage Symbol Min. Typ. Max. Unit VCCS 3.0 — 5.25 V 1 Video ICs BA7780KV GND L 49 INV OUT L GC OUT L MTX IN L MTX OUT L BL OUT L HPF IN L BIAS L EXTC L 45 OUT AMP IN L VREG L 46 PRE OUT L INT IN L 47 EXT IN L SUB IN L 48 MODE 43 BG •Block diagram 44 43 42 41 40 39 38 37 36 35 34 33 13dB 13dB REC EXT GC – + MIX1 IN L 50 32 OUT L 31 MIC MONO INT: ON INT 30 Z B GZ CONT 51 SUB INV2 OUT 52 SUB INV2 IN 53 29 Z A 15dB EXT RFLT –+ 28 Z SENSE SUB BUF2 OUT 54 5dB BALANCE INT 27 Z POINT 26 GAIN CONT SUB VCA OUT 55 25 EX VCC OUT SUB VCA IN 56 MIX 24 EX VCC RFLT SUB INV1 OUT 59 23 VCC 5dB INT BALANCE 22 Z AC HPFC SUB BUF2 IN 58 BIAS MIX2 OUT 57 CImt SUB BUF1 OUT 60 EXT 15dB SUB BUF1 IN 61 MIX1 OUT 62 20 IN MONI 19 HPF CONT MIX INT INT: 0N MIX1 IN R 63 REG 13dB GND R 64 2 21 Z BC EXT 18 BIAS SUB 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 INT IN R VREG R EXT IN R MODE 6 PRE OUT R OUT AMP IN R INV OUT R GC OUT R MTX IN R MTX OUT R BL OUT R HPF IN R BIAS R EXTC R 17 OUT R 01 SUB IN R + – RIPL 13dB GC Video ICs BA7780KV •Pin descriptions Pin No. Pin name 1 RIPL 2 Function Pin voltage (V) Format For bias ripple filter capacitor 1.65 50kΩ SUB IN R Sub microphone input 1.65 100kΩ 3 INT IN R Internal microphone input 1.65 75kΩ 4 VREG R Regulator output 2.5 C 5 EXT IN R External microphone input 1.65 75kΩ Mode control 6 input 6 MODE 6 — 25kΩ 7 PRE OUT R Preamplifier output 1.65 EF (P - P) 8 OUT AMP IN R Out amplifier input 1.65 100kΩ 9 INV OUT R Inverter output 1.65 EF (P - P) 10 GC OUT R Gain control amplifier output 1.65 EF (P - P) 11 MTX IN R Matrix amplifier input 1.65 B 12 MTX OUT R Matrix amplifier output 1.65 EF (P - P) 13 BL OUT R Zoom balance circuit output 1.65 EF (P - P) 14 HPF IN R HPF input 1.65 100kΩ 15 BIAS R Bias output 1.65 EF (P - P) 16 EXTC R For connection of out amplifier output inhibit capacitor 2.3 C 17 OUT R Signal output 1.65 C (P - P) Sub bias output 18 BIAS SUB 19 HPF CONT 1.65 EF (P - P) HFP control input — 20 IN MONI 10kΩ Input switch decision signal output — 21 C Z BC For connection of noise cutting capacitor for zoom control signal — B 22 Z AC For connection of noise cutting capacitor for zoom control signal — B 23 VCC VCC 3.3 — — 24 EX VCC Current limiter VCC 4.75 25 EX VCC OUT Current limiter output 4.5 C 26 GAIN CONT Gain control amplifier switch input — 50kΩ 27 Z POINT Cross-point variation input for zoom balance circuit — B 28 Z SENSE Sensitivity variation input for zoom balance circuit — B 29 Z A Zoom control input — B 30 Z B Zoom control input — B 31 MIC MONO External microphone monaural decision signal output — C EF (P - P) 32 OUT L Signal output 1.65 33 EXTC L For connection of out amplifier output inhibit capacitor 2.3 C 34 BIAS L Bias output 1.65 EF (P - P) 35 HPF IN L HPF input 1.65 100kΩ 36 BL OUT L Zoom balance circuit output 1.65 EF (P - P) 37 MTX OUT L Matrix amplifier output 1.65 EF (P - P) 38 MTX IN L Matrix amplifier input 1.65 B 39 GC OUT L Gain control amplifier output 1.65 EF (P - P) 40 INV OUT L Inverter output 1.65 EF (P - P) 41 OUT AMP IN L Out amplifier input 1.65 100kΩ 42 PRE OUT L Preamplifier output 1.65 EF (P - P) 3 Video ICs BA7780KV Function Pin voltage (V) Format — 25kΩ External microphone input 1.65 75kΩ VREG L Regulator output 2.5 C 46 INT IN L Internal microphone input 1.65 75kΩ 47 SUB IN L Sub microphone input 1.65 100kΩ 48 BG For regulator ripple filter capacitor 1.25 10kΩ 49 GND L 50 MIX 1 IN L Pin No. Pin name 43 MODE 43 Mode control 43 input 44 EXT IN L 45 Left channel GND Mixer amplifier input — 1.65 100kΩ 51 GZ CONT Sub VCA control input — 50kΩ 52 SUB INV2 OUT Sub inverter 2 output 1.65 EF (P - P) 53 SUB INV2 IN Sub inverter 2 input 1.65 B 54 SUB BUF2 OUT Sub buffer 2 output 1.65 EF (P - P) 55 SUB VCA OUT Sub VCA output 1.65 EF (P - P) 56 SUB VCA IN Sub VCA input 1.65 100kΩ 57 MIX2 OUT Mixer 2 output 1.65 EF (P - P) 58 SUB BUF2 IN Sub buffer 2 input 1.65 100kΩ 59 SUB INV1 OUT Sub inverter 1 output 1.65 EF (P - P) 60 SUB BUF1 OUT Sub buffer 1 output 1.65 EF (P - P) 61 SUB BUF1 IN Sub buffer 1 input 1.65 100kΩ 62 MIX1 OUT Mixer 1 output 1.65 EF (P - P) 63 MIX1 IN R Mixer 1 input 1.65 100kΩ 64 GND R — — Right channel GND ∗ EF: emitter follower, P-P: push pull, B: base, and C: collector. All numerical values are standardized values. 4 — Video ICs BA7780KV Electrical characteristics •Measurement conditions Input signal level Int = – 31.5dBV Ext = – 38.5dBV Sub = – 33.5dBV (1kHz) Monitoring pins: 17 and 32 ∗ 1 JIS–A filter used ∗ 2 400Hz to 30kHz filter used Unless otherwise noted, the following conditions apply: Ta = 25°C, VCC3.3V, external supply voltage (pin 24) = 4.75V, pin 19 = “H” or open, pin 26 = 1 / 2VCC, pin 51 = 0.58 × pin 4, pin 27 = 0.733 × pin 4, pin 28 = 0.80 × pin 4, pin 29 = 2.2V, pin 30 = 2.2V Parameter Symbol Min. Typ. Max. Unit Conditions IqE — 8.5 12.0 mA INT / EXT MIC IN, No input Voltage gain 1 GVE 27.0 28.0 29.0 dB EXT MIC IN Voltage gain 2 GVIH 21.5 24.5 27.5 dB INT MIC IN, GAIN CTL H Voltage gain 3 GVIM 18.5 21.5 24.5 dB INT MIC IN, GAIN CTL M Voltage gain 4 GVIL 16.5 18.5 21.5 dB INT MIC IN, GAIN CTL L Distortion 1 THDW — 0.05 0.5 % INT MIC IN, WIDE, Vo = 300mVrms Distortion 2 THDE — 0.1 0.25 % EXT MIC IN, VO = 300mVrms Distortion 3 THDZ — 0.15 0.5 % Maximum output VOM 0.75 0.95 — Vrms INT / EXT MIC IN, THD = 1%∗2 Output noise voltage 1 (EXT) VONE — 30 60 µVrms EXT MIC IN, Rg = 1kΩ∗1 Output noise voltage 2 (INT, WIDE) VONW — 30 60 µVrms Output noise voltage 3 (INT, ZOOM) VONZ — 60 120 µVrms Input switch crosstalk (INT to EXT) CTIE — – 76 – 70 dB Current dissipation INT MIC IN, ZOOM, V O = 300mVrms INT MIC IN, Rg = 1kΩ∗1 GAIN CTL H INT MIC IN, Rg = 1kΩ∗1 Pins 29 and 30 = 0V, GAIN CTL H Note 1 Interchannel crosstalk CTCH — – 76 – 70 dB Note 2 GC OUT L / R gain differential GVGLR – 1.5 0.0 1.5 dB INT MIC IN, HML, 10 39 Inverter OUT L / R gain differential GVILR – 1.5 0.0 1.5 dB INT MIC IN, HML, 9 40 Internal microphone power supply output voltage VREG 2.3 2.5 2.75 V Pins 4 and 45 output current for 30kΩ load External power supply output voltage VEXT 4.3 4.5 — V Pin 25 DC for pin 25 output current of 25mA ILTD — — 30 mA VHSWH 1.6 — VCC V “H” level, pin 6 / 43 DC VHSWL 0 — 0.7 V “L” level, pin 6 / 43 DC VHGH 2.8 — VCC V “H” level, pin 26 DC VHGM 1.3 — 2.0 V “M” level, pin 26 DC VHGL 0 — 0.5 V “L” level, pin 26 DC VHHPFH 2.0 — VCC V HPF OFF, 19pin DC External power supply limit current Input switching CTL holding voltage Gain switching CTL holding voltage HPF, CTL holding voltage VHHPFL MIX 1 gain MIX 2 gain 0 GVM1-1 – 7.0 GVM1-2 – 1.0 GVM2-1 6.0 GVM2-2 – 1.0 Pin 25 output current when grounded — 0.5 V HPF ON, 19pin DC – 6.0 – 5.0 dB 63→62 / 50→62 pin 0 1.0 dB Gain differential for pins 63 to 62 and 50 to 62 7.0 8.0 dB INT L / M / H, 2→57, 47→57pin 0 1.0 dB Gain differential for pins 2 to 57 and 47 to 57 5 Video ICs Parameter BA7780KV Symbol Min. Typ. Max. Conditions Unit 12→13 or 37→36 pin ZOOM - BALANCE Gain 1 Rch / Lch GV Z1-1 – 23.0 – 20.0 – 17.0 GV Z1-2 – 11.7 GV Z1-3 ZOOM - BALANCE Gain 2 Rch / Lch – 2.0 dB 29, 30 pin 0.0V (DC) – 7.7 – 4.7 dB 29, 30 pin 0.8V (DC) 1.0 4.0 dB 29, 30 pin 2.2V (DC) 52→13 or 52→36 pin GVZ2-1 – 23.0 – 20.0 – 17.0 GV Z2-2 – 11.7 GVZ2-3 – 2.0 dB 29, 30 pin 2.2V (DC) – 7.7 – 4.7 dB 29, 30 pin 1.4V (DC) 1.0 4.0 dB 29, 30 pin 0.0V (DC) 28 pin 0.8 × 4pin, 29 30 pin 1.1V, ZOOM - BALANCE 12→13 or 37→36 pin Variable position GV Z3–1 – 2.5 0.5 3.5 dB 27 pin 0.64 × 4pin (DC) Rch / Lch GV Z3–2 – 7.5 – 4.5 – 1.5 dB 27 pin 0.733 × 4pin (DC) GV Z3–3 – 20.6 – 17.0 – 12.0 dB 27 pin 0.82 × 4pin (DC) 27 pin 0.733 × 4pin, 29 30 pin 0.4V, ZOOM - BALANCE 12→13 or 37→36 pin 28 pin 0.59 × 4pin (DC) Variable slope GV Z4–1 – 5.5 – 2.5 0.5 Rch / Lch GVZ4–2 – 9.5 – 6.5 – 3.5 dB 28 pin 0.69 × 4pin (DC) GV Z4–3 – 17.5 – 14.5 – 11.5 dB 28 pin 0.8 × 4pin (DC) Sub VCA gain 56pin 55pin dB GV VCA1 – 5.0 – 3.0 – 1.0 dB 51 pin 0.74 × 4pin (DC) GV VCA2 – 2.0 0.0 2.0 dB 51 pin 0.58 × 4pin (DC) GV VCA3 1.0 3.0 5.0 dB 51 pin 0.48 × 4pin (DC) Note 1: Input switch crosstalk measurement method: (pin 19 = “H” or open, pin 26 = GND, pin 27 = 0.733 × pin 4, pin 28 = 0.80 × pin 4, pin 29 = 2.2V, pin 30 = 2.2V) Input 1kHz signals on the INT input pins (3 and 46) in INT input mode that give a distortion of 1% at the signal output pins (17 and 32), then connect the EXT input pins (5 and 44) to GND via Rg = 1kΩ Switch to EXT input mode, and measure the relative output level of the output pins (17 and 32). Note 2: Interchannel crosstalk measurement method: The mode pin conditions are the same as for input switch crosstalk. Connect the input pin of the channel to be measured to GND via Rg = 1kΩ. Input a 1kHz signal on the other channel's input that gives a distortion of 1% on the signal output pins (17 and 32), and measure the relative output level between the signal output pins (17 and 32). 6 01 13dB 02 03 04 REG 0.1 MODE6 07 0.1 08 09 10 GC GC 39 38 37 0.1 10k 10k 11 12 INT: ON 13 0.1 1 2 SW2 14 EXT INT INT 15dB 5dB 35 EXT 36 15dB 5dB INT: ON +– 06 40 BIAS 05 13dB BALANCE BALANCE EXT INT INT 41 13dB 42 15 34 CImt 33 16 HPFC EXT MIC IN + 64 RFLT 43 EXT 44 2200p INT MIC IN 10k 3 2 32k 1 10 0.1 MIX MIX 45 REG RFLT 46 10k 10k 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 SUB BIAS 470p 63 62 61 60 59 58 0.1 0.1 0.1 57 56 55 54 + – 0.1 10k 10k 53 52 51 0.1 13dB 47 30k 50 48 0.1 –+ 0.1 0.1 49 0.1 0.1 SUB MIC IN + 2 SW3 0.022 GND 10 1 0.1 GZ CONT SUB MIC IN INT MIC IN EXT MIC IN MODE43 Lch OUT Rch OUT HPF ON / OFF IN MONI Z BC Z AC VCC EX VCC IN EX VCC OUT GAIN CONT Z POINT Z SENSE Z A Z B MIC MONO Video ICs BA7780KV •Measurement circuit 470p 2200p 0.022 30k 0.1 0.1 SW1 Units: R [Ω] C [µF] Fig. 1 7 Video ICs BA7780KV •Measurement circuit switching table (blank cells: no spesification) SW1 Parameter SW2 SW3 MODE6 MODE43 GAIN CTL Signal input pin H, L M — L L M Ext H — H Int — — M Int — — L Int — H L M Int — L L — Ext — H L M Sub — H, L L L Int, Ext, Sub — L L — — — H L H — — — H L H — 2 — — L L L Int INT 2 — — H L M Int EXT 2 — — L L — Ext GC out L / R gain differential 1 — — H L H, M, L Int Inverter OUT L / R gain differential 1 — — H L H, M, L Int Internal microphone power supply voltage — — — — — — — External power supply output voltage — — — — — — — External power supply limit current — — — — — — — 2 — — H Vth — Int, Ext 2 — — Vth L — Int, Ext 2 — — H L Vth Int 2 — — H L Vth Int — Current dissipation 1 1 1 Voltage gain 1 — — — Voltage gain 2 — — — Voltage gain 3 — — — Voltage gain 4 — — — Distortion 1 2 — Distortion 2 2 — Distortion 3 1 — Maximum output 1 — Output noise voltage 1 (EXT) 2 — Output noise voltage 2 (WIDE) 2 — Output noise voltage 3 (ZOOM) 3 Input switch crosstalk (INT to EXT) Interchannel crosstalk Input switching CTL holding voltage Gain switching CTL holding voltage H, L 2 — H L Vth Int HPF, CTL holding voltage 2 2.1 2.1 H L — Int, Vth of pin 19 MIX 1 gain — — — H L M Int MIX 2 gain — — — H L — Sub ZOOM - BALANCE Gain 1 2 — — H L M Int ZOOM - BALANCE Gain 2 1 — — H L M Sub ZOOM - BALANCE Variable position 2 — — H L M Int ZOOM - BALANCE Variable inclination 2 — — H L M Int Sub VCA gain — — — H L — Sub ∗ Gain CTL pin 26. H, M, and L are VCC, 1/2VCC, and GND respectively. Measure the voltage range that maintains the mode for Vth. 8 10k 05 06 EXT 0.1 08 13dB 07 09 10k 10 GC 0.1 3300 11 6800p 6800p 33k EXT INT 13 35 22k 22k 15 34 0.022 8200 14 EXT INT 15dB 5dB 12 INT: 0N 36 15dB 5dB 37 INT: 0N 12k 10k 0.1 0.022 6800 04 3300 EXT MIC IN 0.1 2200 03 38 +– 2200 02 REG INT GC 39 0.022 INT MIC IN 01 13dB MIX BALANCE BALANCE 40 BIAS SUB MIC IN 64 63 62 41 13dB 42 CImt 33 16 HPFC + 0.1 10k 0.1 61 60 RFLT RFLT 43 8200 0.022 2200p 10 1k 1500 59 58 MIX 2700p 10k 0.01 10k + – 57 56 55 54 53 INT EXT 44 33k 6800p 6800p 0.022 6800p 0.010 0.1 10k 10k 0.1 47k 52 0.1 51 REG 45 0.1 13dB 46 10k 50 47 10k 12k 3300 0.022 GND 3900p 10k 0.1 49 48 0.1 3300 –+ GZ CONT + 0.022 6800 0.1 5600p 10 2200 2200 0.047 SUB MIC IN INT MIC IN EXT MIC IN 17 470p HPF ON / OFF Rch OUT IN MONI 19 18 Z BC 22 20 VCC Z AC 23 21 EX VCC OUT EX VCC IN 24 GAIN CONT 26 25 Z SENSE 29 Z POINT Z A 30 27 Z B 31 28 Lch OUT MIC MONO 32 SUB BIAS 470p Video ICs BA7780KV •Application example 2200p 0.022 0.1 0.047 0.1 Units: R [Ω] C [µF] Fig. 2 9 Video ICs BA7780KV Operation notes •Points to note regarding zoom operation When using a microprocessor to vary the voltages on pins 29 and 30 after presetting the electronic volume sensitivity and control voltage range, and with the pin 27 and 28 voltage fixed at a certain level, it is possible to minimize drift in the zoom characteristics due to tempreature fluctuations and differences between individual ICs by setting the pin 27 and 28 voltages using resistive voltage divider circuits connected to the pin 4 regulator voltage output. 4 27 28 – 10 – 15 – 20 1.64V 1.84V 1.84V 1.94V 1.94V 2.04V 2.04V 12→13, 37→36pin 52→13, 52→36pin 0 0.1 0.6 1.1 1.6 2.1 2.2 29, 30pin CONTROL VOLTAGE: VCTL (V) Fig. 4 Zoom control slope variation characteristics •External dimensions (Units: mm) 12.0 ± 0.3 10.0 ± 0.2 32 64 17 1.4 ± 0.1 1 0.10 33 49 0.5 16 0.125 ± 0.1 0.2 ± 0.1 0.10 VQFP64 10 0.5 12.0 ± 0.3 10.0 ± 0.2 48 –5 27pin 27pin = 1.64V Ta = 25°C 0 = –5 28pin = 28pin 17, 32pin OUTPUT ATTENUATION LEVEL: GVZ1 (dB) Ta = 25°C 0 = 17, 32pin OUTPUT ATTENUATION LEVEL: GVZ1 (dB) •Electrical characteristic curves 1.67V 1.67V – 10 1.87V 1.87V – 15 2.07V 1.67V – 20 12→13, 37→36pin 52→13, 52→36pin 0 0.1 0.6 1.1 1.6 2.1 2.2 29, 30pin CONTROL VOLTAGE: VCTL (V) Fig. 5 Zoom control position variation characteristics Fig. 3