Video ICs Two-channel VCR PRE / REC amplifier for Digital VCRs BH7272KV The BH7272KV is a head amplifier developed for use in digital video cassette recorders. Both PB and REC have excellent frequency characteristics making this IC an ideal choice for digital recording and playback. The small VQFP48 package facilitates compact design of portable equipment such as video cameras. Applications •Digital video cassette recorders •1)Features The playback amplifier is a differential amplifier with an overall gain of 54dB (Typ.), and has low-noise transistors as the first stage. The feedback circuit is not included, so provide negative feedback for head peak damping, and positive feedback to cancel the input capacitance using external components. 2) The playback AGC amplifier has ± 10dB of control range. 3) The recording current amplifier is a BLT current amplifier. Use external components to construct the head peak damping circuit. 4) Recording limit amplifier is included. Recording AGC amplifier not included. 5) The signal system VCC is 4.9V, and the control system VCC is 3.0V. •Absolute maximum ratings (Ta = 25°C) Parameter Symbol Limits Unit Applied voltage VCC 7.0 V Power dissipation Pd ∗900 mW Operating temperature Topr – 20 ~ + 65 °C Storage temperature Tstg – 55 ~ + 125 °C ∗ When mounted on a 70mm × 70mm × 1.6mm glass epoxy board. ∗ Reduced by 9.0mW for each increase in Ta of 1°C over 25° . •Recommended operating conditions (Ta = 25°C) Parameter Symbol Min. Typ. Max. Unit Signal system VCC 5V 4.6 4.9 5.2 V 14, 19, 38, 47pin Conditions Control system VCC 3V 2.8 3.0 3.2 V 16pin 䊊Not designed for radiation resistance. 1 Video ICs BH7272KV GND PB SW B OUT PB SW A OUT N.C. PB MUTE AGC DET GATE PB AGC IN PB AGC FILTER PB AGC LEVEL ADJ PB AGC DET IN PB AGC OUT GND REC IN •Block diagram 36 35 34 33 32 31 30 29 28 27 26 25 DET 37 24 LIMIT LEVEL adj 23 LIMIT Vth adj 22 REC LIMIT – OUT 21 REC LIMIT + OUT 20 GND 19 Vcc 4.9V 18 REC GATE 17 REC “H” 16 Vcc 3.0V 15 BIAS FILTER 14 Vcc 4.9V 13 REC BTL B I0adj LIMIT Vcc 4.9V 38 3rd AGC PB 2nd OUT A 39 PB 2nd OUT B 40 2nd VAMP PB 2nd IN A 41 PB 2nd IN B 42 BH7272KV Balance PB SW – OUT 43 PB SW + OUT 44 Balance BF Bias HEAD SW CTRL 45 PB “H” 46 IAMP •V CC 10k 10k 1k 1k PRE IAMP PRE 1 2 3 4 5 6 7 8 9 10 11 12 HEAD – B REC FB – B GND PB SW + OUT PB SW – OUT GND REC FB – A HEAD – A HEAD + A REC FB + A 48 HEAD + B REC BTL A I0adj 47 IAMP REC FB + B Vcc 4.9V IAMP / GND pins Pin No. Pin name Function 14 8 VCC 4.9V GND REC current amplifier As above 19 20 26 VCC 4.9V GND GND Bias, REC limiter amplifier Bias, control logic REC limiter amplifier 38 37 VCC 4.9V GND PB amplifier, PB AGC, peak amplifier As above 47 5 VCC 4.9V GND PB first-stage amplifier PB first-stage amplifier, REC current amplifier 16 VCC 3.0V Control logic ∗ Make sure that the voltages at VCC and GND pins does not sway. ∗ Be especially careful of the VCC and GND for the first-stage amplifier. ∗ The playback system has high gain, so take care to ensure that the output does not find its way back to the input. 2 Video ICs BH7272KV •Electrical characteristics (unless otherwise noted, Ta = 25°C, V CC Parameter = 4.9V, 3.0V and f = 4.0MHz) Symbol Min. Typ. Max. Unit Sleep-mode circuit current Iq (S) — 14 30 mA No signal Circuit current Iq (P) — 34 56 mA No signal Voltage gain ch-1 GVP1 50 54 58 dB Pin 35 output measurement when pin 11 input is 0.3mVP-P Voltage gain ch-2 GVP2 50 54 58 dB Pin 35 output measurement when pin 2 input is 0.3mVP-P Voltage gain differential ∆GVP – 1.5 — + 1.5 dB ∆GVP = GVP1 – GVP2 Frequency characteristics ∆GVf – 3.0 ± 0.0 — dB Pin 35 output level differential when f = 8.0 / 1.0MHz and VIN = 0.3mVP-P Crosstalk CTP — – 46 – 35 dBc Pin 35 output level differential when for pin 45: H / L PB mute attenuation MUP — – 57 – 35 dBc Pin 35 output level differential when pin 33 goes from L to H and pin 2 input is 0.3mVP-P AGC output level VAGC 230 280 330 mVP-P AGC control sensitivity ∆VAGC — 0.2 2.0 dB Pin 27 output level differential when pin 31 input VIN = 150 to 600mVP-P AGC frequency characteristics ∆GVAF – 3.0 ± 0.0 — dB Pin 27 output level differential when f = 8.0 / 1.0MHz and pin 31 input is VIN = 300mVP-P Circuit current Iq (R) — 54 80 mA No signal Recording current level 1 IOR1 14 20 26 mAP-P Pin 11 output measurement when pin 25 input is 0.3VP-P Recording current level 2 IOR2 14 20 26 mAP-P Pin 2 output measurement when pin 25 input is 0.3VP-P REC frequency characteristics ∆IOF – 3.0 ± 0.0 — dB f = 8.0 / 1.0MHz, pin 25 input = 0.3VP-P REC mute attenuation MUR — – 60 – 35 dBc Pins 2, 11 output level differential VTH46H 2.0 — 3.0 V Pins 46 voltage to hold PB PB holding voltage VTH46L 0.0 — 1.0 V Pin 46 voltage to hold PB REC holding voltage VTH17H 2.0 — 3.0 V Pin 17 voltage to hold REC REC holding voltage VTH17L 0.0 — 1.0 V Pin 17 voltage to hold REC HSW holding voltage VTH45H 2.0 — 3.0 V Pin 45 voltage to hold HSW HSW holding voltage VTH45L 0.0 — 1.0 V Pin 45 voltage to hold HSW RECGATE holding voltage VTH18H 2.0 — 3.0 V Pin 18 voltage to hold RECGATE RECGATE holding voltage VTH18L 0.0 — 1.0 V Pin 18 voltage to hold RECGATE Conditions 〈Playback system〉 Pin 27 output measurement when pin 31 input is VIN = 300mVP-P 〈Recording system〉 〈Logic system〉 PB holding voltage ∗ Note: dBc: dB below carrier (used to express relative level from carrier reference for convenience sake) 3 Video ICs BH7272KV 34 REC IN PB AGC OUT 31 30 29 5.1k 0.1µ 1000p 32 50k 33 PB AGC IN AGC DET GATE 35 0.1µ PB RF OUT 36 MUTE PB RF OUT •Measurement circuit (playback system) 28 27 26 25 DET 37 24 LIMIT LEVEL adj 23 LIMIT Vth adj LIMIT Vcc 4.9V 38 3rd AGC 39 22 40 21 2nd VAMP 41 20 0.1µ 0.1µ BH7272KV 42 Balance 19 Vcc 4.9V 18 REC GATE 17 REC “H” Balance 43 BF 44 Bias HEAD SW CTRL 45 16 Vcc 3.0V 0.1µ 46 15 IAMP PRE 5 6 7 8 9 10 PRE IN A1 Fig. 1 4 12 11 1k 1k 1k PRE IN B2 PRE IN B1 1k 10 10 1000p 4 1000p 3 PRE IN A2 2 0.1µ 1 1k 0.1µ 1k 10 10 48 10k PRE IAMP 0.1µ I0adj 10k IAMP 1000p 47 0.1µ Vcc 4.9V IAMP 1000p PB “H” 14 Vcc 4.9V 13 I0adj Video ICs BH7272KV 34 REC IN PB AGC OUT 31 30 29 28 5.1k 0.1µ 1000p 32 50k 33 PB AGC IN AGC DET GATE 35 0.1µ PB RF OUT 36 MUTE PB RF OUT •Measurement circuit (recording system) 27 26 25 DET 37 24 LIMIT LEVEL adj 23 LIMIT Vth adj LIMIT Vcc 4.9V 38 3rd AGC 39 22 40 21 2nd VAMP 41 20 0.1µ 0.1µ BH7272KV 42 Balance 19 Vcc 4.9V 18 REC GATE 17 REC “H” Balance 43 44 BF Bias HEAD SW CTRL 45 16 Vcc 3V 0.1µ 47 I0adj 48 IAMP IAMP 10k IAMP 10k PRE 1k 1000p 1 2 IAMP PRE 3 10 4 5 6 7 1k 8 9 10 11 10 14 Vcc 4.9V 13 I0adj 12 1000p Vcc 4.9V 15 1000p 46 1000p PB “H” REC OUT A REC OUT B Fig. 2 5 Video ICs BH7272KV operation •(1)Circuit Control logic table Mode REC PAUSE REC PB After recording Control signals Circuit operation PB-H 46pin REC-H 17pin HSW 45pin REC GATE 18pin REC REC-A REC-B PB PB-A PB-B L L × × × × × × × × L H L L 1 × × × × × L H L H 1 × 1 × × × L H H L 1 × × × × × L H H H 1 1 × × × × H L L × × × × 1 × 1 H L H × × × × 1 1 × H H L L 1 × × 1 × 1 H H L H 1 × 1 1 × × H H H L 1 × × 1 1 × H H H 1 1 × 1 × × H Low: 1V or less High: 2V or more ×: Irrelevant Notes 1: Operating ×: Power save state (2) Mute circuit 33pin Operation L MUTE OFF H MUTE ON Low: 1V or less High: 2V or more — MUTE 33pin Notes (3) AGC DET GATE circuit AGC DET GATE 32pin Notes 6 32pin Operation L AGC detection on H AGC detection off Low: 1V or less High: 2V or more — Video ICs BH7272KV •I / O circuits Pin No. Pin name Pin voltage REC FB + B HEAD + B 2.5 (2.5) 2.5 (2.5) Equivalent internal circuit Function 20 1 2 5k REC DC feedback HEAD B 1 2 20 20 3 4 HEAD – B REC FB – B 2.5 (2.5) 2.5 (2.5) 5k HEAD B REC DC feedback 4 3 20 5 GND — PB SW + OUT 0.2 (–) — GND for PB 1st stage amplifier and REC current amplifier 10k 1st stage amplifier positive phase output PB feedback 1k 6 6 1k 1k 7 PB SW – OUT 0.2 (–) 10k 7 1st stage amplifier reverse phase output PB feedback 1k 8 GND — — GND for REC current amplifier ∗ The pin voltages in brackets are for REC mode, all others are for PB mode. 7 Video ICs Pin No. BH7272KV Pin name Pin voltage REC FB – A HEAD – A 2.5 (2.5) 2.5 (2.5) Equivalent internal circuit Function 20 9 10 REC DC feedback HEAD A 5k 9 10 20 20 11 12 HEAD + A REC FB + A 2.5 (2.5) 2.5 (2.5) HEAD A REC DC feedback 5k 12 11 20 12.8k 13 12.8k 13 REC BTL A I0adj 2.5 (3.4) HEAD A recording current adjustment 2.5k 14 VCC 5V — 15 BIAS FILTER 2.5 (2.5) — 400 VCC for REC current amplifier 25k Bias filter for head connection pins (pins 2, 3, 10, and 11) 15 25k 16 VCC 3V — — ∗ The pin voltages in brackets are for REC mode, all others are for PB mode. 8 VCC for logic circuits Video ICs Pin No. BH7272KV Pin name Pin voltage Equivalent internal circuit Function REC “H” 0.0 (0.0) 18 REC GATE 0.0 (0.0) 19 VCC 5V — — VCC for bias and REC limiter amplifier 20 GND — — GND for bias and control logic 15k 17 17 Mode control 100k 15k 18 Mode control 100k 400 21 REC LIMIT + OUT 2.5 (2.5) 500 21 REC limiter amplifier positive phase output 400 400 22 REC LIMIT – OUT 2.5 (2.5) 500 22 REC limiter amplifier reverse phase output 400 35k 23 LIMIT Vth adj — (1.5) 23 15k REC limiter amplifier input threshold level adjustment ∗ The pin voltages in brackets are for REC mode, all others are for PB mode. 9 Video ICs Pin No. BH7272KV Pin name Pin voltage REC LEVEL adj 1.5 (1.5) Equivalent internal circuit 70k 24 Function 70k 5k 24 REC limiter amplifier output level adjustment 30k 1k 30k 800 500 25 REC IN — (1.5) 26 GND — 27 PB AGC OUT 2.4 (–) 28 29 PB AGC DET IN PB AGC LEVEL adj 2.5 (–) 3.6 (3.6) PB AGC FILTER — (–) 30 25 REC input 500 GND for REC limiter amplifier — 9k 7k 16k 18k 29 PB AGC IN 2.5 (–) Playback system AGC filter 200 31 2k ∗ The pin voltages in brackets are for REC mode, all others are for PB mode. 10 Playback system AGC detector input Playback system AGC level adjustment 28 30 31 Playback system AGC output 27 Playback system AGC input Video ICs Pin No. BH7272KV Pin name Pin voltage PB AGC GATE 0.0 (0.0) Equivalent internal circuit Function 15k 32 32 PB AGC detection control 100k 15k 33 MUTE 0.0 (0.0) 33 Playback system mute control 100k 34 N.C. — — 35 36 PB SW A OUT PB SW B OUT 3.2 (–) 3.2 (–) 37 GND — — 38 VCC 5V — — 39 40 PB2nd OUT B PB2nd OUT A 2.5 (–) 2.5 (–) 35 — 36 GND for PB amplifier, AGC, and peak amplifier VCC for PB amplifier, AGC, and peak amplifier 380 39 Playback system amplifier output 40 Playback system 2nd amplifier output Playback system 2nd amplifier output ∗ The pin voltages in brackets are for REC mode, all others are for PB mode. 11 Video ICs BH7272KV Pin No. Pin name Pin voltage 41 42 PB2nd IN A PB2nd IN B 2.5 (–) 2.5 (–) Equivalent internal circuit 41 Function 42 80 1k 1k Playback system 2nd amplifier input Playback system 2nd amplifier input 1k 43 PB SW + OUT 2.0 (–) 43 1st stage amplifier positive phase output 1k 44 PB SW – OUT 2.0 (–) HSW 0.0 (0.0) 44 1st stage amplifier reverse phase output 15k 45 45 Mode control 100k 15k 46 46 47 PB “H” VCC 5V 0.0 (0.0) Mode control 100k — — VCC for PB 1st stage amplifier — 12.8k 48 12.8k 48 REC BTL B I0adj 2.5 (3.4) HEAD B recording current adjustment 2.6k ∗ The pin voltages in brackets are for REC mode, all others are for PB mode. 12 400 Video ICs BH7272KV 36 35 34 30 29 28 5.1k 0.1µ 31 REC IN PB AGC OUT 1000p∗ 32 50k∗ AGC DET GATE 33 0.1µ MUTE PB RF OUT •Application example 27 26 25 DET 37 24 LIMIT LEVEL adj 23 LIMIT Vth adj LIMIT Vcc 4.9V 38 3rd AGC 39 22 40 21 2nd VAMP 41 ∗0.1µ 20 ∗0.1µ BH7272KV 42 Balance 19 Vcc 4.9V 18 REC GATE 17 REC “H” Balance 43 BF 44 Bias HEAD SW CTRL 45 16 Vcc 3.0V 0.1µ 46 15 IAMP 48 10k IAMP PRE 1k 1 2 3 4 5 6 7 1k 8 9 10 11 HEAD B 14 Vcc 4.9V 13 I0adj 12 ∗1000p I0adj 10k IAMP PRE ∗1000p 47 ∗1000p Vcc 4.9V IAMP ∗1000p PB “H” HEAD A ∗ Requires adjustment Fig. 3 13 Video ICs BH7272KV •External dimensions (Units: mm) 9.0 ± 0.3 7.0 ± 0.2 24 48 13 1 1.425 ± 0.1 0.10 25 0.5 12 0.125 ± 0.1 0.2 ± 0.1 0.10 VQFP48 14 0.5 7.0 ± 0.2 9.0 ± 0.3 36 37