Ordering number : EN5764 Monolithic Linear IC LA7566 VIF/SIF IF Signal-Processing Circuit with TV/VCR PAL and NTSC Multisound Support Overview Package Dimensions The LA7566 is a VIF/SIF IC that supports PAL and NTSC multisound and that adopts a semi-adjustment-free system. To simplify adjustment, the VIF block adopts a technique in which AFT adjustment is no longer required by VCO adjustment. The SIF block supports audio multidetection by adopting a PLL detection technique. The SIF block provides 4 inputs with IC internal switching for easy design of multi-sound systems. Additionally, these switches can also be used for video system sound trap switching. The LA7566 also includes a buzz canceller that suppresses Nyquist buzz to achieve improved audio quality. unit: mm 3067-DIP24S [LA7566] SANYO: DIP24S [VIF Block] • VIF amplifier • PLL detector • BNC • RF AGC • EQ amplifier • AFT • IF AGC • Buzz canceller [First SIF Block] • First SIF amplifier • First SIF detector • AGC [SIF Block] • Multiple input switch • Limiter amplifier • PLL FM detector Features • No coils are used in the AFT and SIF blocks, making these circuits adjustment free. • PAL / NTSC multisound system can be constructed easily. • Built-in buzz canceller for excellent audio performance Allowable power dissipation, Pd max — W Functions Ambient temperature, Ta — °C Specifications Maximum Ratings at Ta = 25°C Parameter Maximum supply voltage Circuit voltage Symbol VCC max V7, V9, V10, V17 I1 Circuit current Allowable power dissipation Conditions Ratings 10 VCC Unit V V –2 mA mA I13 –3 I18 –10 mA Pd max 720 mW Operating temperature Topr –20 to +70 °C Storage temperature Tstg –55 to +150 °C SANYO Electric Co.,Ltd. Semiconductor Bussiness Headquarters TOKYO OFFICE Tokyo Bldg., 1-10, 1 Chome, Ueno, Taito-ku, TOKYO, 110-8534 JAPAN 31398HA (OT) No. 5764-1/11 LA7566 Operating Conditions at Ta = 25°C Parameter Symbol Recommended supply voltage VCC Operating supply voltage range VCC op Conditions Ratings Unit 9 V 4.6 to 9.5 V Operating Characteristics at Ta = 25°C, VCC = 9 V, fp = 38.9 MHz Parameter Symbol Conditions Ratings min typ Unit max [VIF Block] Circuit current I3 45 53 Maximum RF AGC voltage V9H 7.5 8.1 Minimum RF AGC voltage V9L Input sensitivity VIN AGC range GR VIN max Maximum allowable input No-signal video output voltage Sync tip voltage Video output level S1 = OFF 61 mA 0 0.5 V 28 34 40 dBµV 45 50 dB 95 100 dBµV V V13 3.7 4.0 4.3 V13 tip 1.3 1.6 1.9 V VO 1.7 2.0 2.3 Vp-p V Black noise threshold voltage VBTH 0.7 1.0 1.3 Black noise clamp voltage VBCL 2.0 2.3 2.6 Video signal-to-noise ratio S/N 48 52 C-S beat IC-S Frequency characteristics fC 6 MHz V V dB 44 49 dB –3 –1.5 dB Differential gain DG 3 8 % Differential phase DP 3 8 deg Maximum AFT voltage V10H 7.5 8.5 9.0 Minimum AFT voltage V10L 0 0.2 1.0 V AFT detection sensitivity Sf 29 37 47 mV/kHz VIF input resistance Ri 38.9 MHz 1.5 VIF input capacitance Ci 38.9 MHz 3 APC pull-in range (U) fPU 1.0 V kΩ pF 1.5 MHz –1.5 –0.8 AFT tolerance frequency 1 dfa1 –500 0 +500 VCO 1 maximum variability range (U) dfu 1.7 2.0 VCO 1 maximum variability range (L) dfl –2 –1 MHz VCO control sensitivity B 1.15 2.3 4.6 kHz/mV APC pull-in range (L) fPL MHz kHz MHz [First SIF Block] Conversion gain VG 32 35 38 dB 5.5 MHz output level SO 84 87 90 mVrms 85 88 91 mVrms Maximum first SIF input SIN max First SIF input resistance RIN(SIF) 33.4 MHz 2 kΩ First SIF input capacitance CIN(SIF) 33.4 MHz 3 pF [SIF Block] Limiting sensitivity VIi(lim) FM detector output voltage VO(FM) AM rejection ratio AMR Total harmonic distortion THD SIF S/N 5.5 MHz ± 30 kHz S/N (FM) 390 50 43 49 dBµV 500 630 mVrms 60 0.2 55 dB 1.5 60 % dB [SIF Switch Block] Switches A, B, and C: H = open, L = ground NTSC mode 6-dB amplifier NTSW 5 6 SIF crosstalk 21 CT21 51 57 dB SIF crosstalk 22 CT22 51 57 dB SIF crosstalk 23 CT23 51 57 dB SIF crosstalk 24 CT24 51 57 dB SW (L) 1.0 1.5 V Switch threshold low-level voltage 7 dB No. 5764-2/11 LA7566 Pin Assignment Application Circuit Diagram A H H H H L L L L Switch B H H L L H L H L C H L H L H L L H 5.5 MHz 6.0 MHz 6.5 MHz 4.5 MHz ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● H : OPEN L : GND No. 5764-3/11 LA7566 Internal Equivalent Circuit Diagram No. 5764-4/11 LA7566 AC Characteristics Test Circuit Diagram Test Circuit Input Impedance Test Circuit (VIF and first SIF input impedance) Impedance analyzer No. 5764-5/11 LA7566 Pin Functions Pin No. Symbol Pin function Equivalent circuit • Audio FM detector output. Deemphasis is switched internally in the IC. (5 kΩ and 7.5 kΩ) 1 FM DET OUT 2 SIF FILTER This switching is linked to the SIF input switch. An external emitter-follower circuit must be provided if the deemphasis is disabled. • Connection for a filter that holds the FM detector output DC voltage at a fixed level. Normally, a 1-µF electrolytic capacitor is used. To improve the low band (around 50 Hz) frequency characteristics, increase the value of this capacitor (C1). • VIF amplifier input. 5 6 VIF IN The input circuit is constructed as a balanced input, and the input has the following impedance characteristics: R ≈ 1.5 kΩ C ≈ 3 pF Continued on next page. No. 5764-6/11 LA7566 Continued from preceding page. Pin No. Symbol Pin function Equivalent circuit • IF AGC filter connection. 7 IF AGC The AGC voltage is created at pin 7 from the signal to which peak detection was applied by the internal AGC detector. Additionally, the IC includes an internal second AGC filter (a lag-lead filter) used to create a dual time constant. A 0.022 µF capacitor is used as the external capacitor. The value of this capacitor must be adjusted according to measurement of the sag, AGC speed, and other circuit aspects. • First SIF input. A DC cut capacitor must be inserted in the input to this circuit. 8 1st SIF IN When a SAW filter is used: The first SIF sensitivity can be increased by inserting an inductor between the SAW and the IC to match the SAW output and IC input capacitances. When an intercarrier system is used: This pin must be connected to ground through a capacitor. • RF AGC output. 9 RF AGC OUT This output controls the tuner RF AGC. This is an opencollector output with an inserted 100-Ω protective resistor. Determine the value of the external bleeder resistor to match the tuner specifications. • AFT output. 10 AFT OUT The AFT center voltage is created with an external bleeder resistor. The AFT gain increases as the value of this bleeder resistor increases. The value of this resistor must not exceed 390 kΩ. This circuit includes a control function that controls the AFT voltage to be equal to the center voltage in weak field reception conditions. Continued on next page. No. 5764-7/11 LA7566 Continued from preceding page. Pin No. 11 12 Symbol Pin function Equivalent circuit • VCO tank circuit used for video detection. VCO See the separately provided documentation for the tank circuit coil (inductor) specifications. • Equalizer circuit. This circuit corrects the video signal frequency characteristics. • Notes on equalizer amplifier design: 13 VIDEO OUT The equalizer amplifier is designed as a voltage follower amplifier with a gain of about 2.3 dB. When the frequency characteristics are corrected, connect an inductor, a capacitor, and a resistor in series between pin 14 and ground. 14 EQ FILTER The equalizer amplifier gain is given by: R1 AV = —— + 1 Z Here, R1 is an IC internal resistor with a value of 1 kΩ. Select Z according to the desired characteristics. However, care is required to prevent distortion at the resonant point determined by Z, where the gain is maximum. 15 PAL VIDEO IN 16 NT VIDEO IN • Equalizer amplifier inputs. Pin 15 is for PAL, and pin 16 for NTSC format signals. These inputs are linked to and switched by the SIF switches. • PLL detector APC filter connection. 17 APC FILTER The APC time constants are switched internally in the IC. When locked, the VCO is controlled over the path A, and the loop gain is reduced. When unlocked and during weak field reception, the VCO is controlled over the path B, thus increasing the loop gain. We recommend values of: R = 150 to 390 Ω, and C = 0.47 µF for the loop filter constants. Continued on next page. No. 5764-8/11 LA7566 Continued from preceding page. Pin No. Symbol Pin function Equivalent circuit • Output for the video signal that includes the SIF carrier. 18 COMP OUT A resistor must be inserted between pin 18 and ground to acquire an adequate drive capability. R ≥ 470 Ω • First SIF output 19 1st SIF OUT The signal output from this pin is passed through a bandpass filter and input to the SIF circuit. This is an emitter-follower output. • The FM detector signal-to-noise ratio can be improved by inserting a filter in the FM detector bias line. 20 FM FILTER C1 should have a value of 0.47 µF or greater, and 1 µF is recommended . If the FM detector is not used, pin 20 must be connected to ground through a 2-kΩ resistor. This stops the FM detector VCO circuit. • SIF inputs. 21 22 23 24 SIF IN (4.5 MHz) Four input pins are provided to support multi-side systems, and a switching function is also included. Since buzzing and bass beating can occur if interference signals, such as the video signal or the chrominance signal, enter these pins, extra care must be taken in designing the input circuit pattern layout. Note that pin 24 also functions as the RF AGC adjustment pin. This pin sets the tuner RF AGC operating point. Also, the FM output and the video output can be muted at the same time by setting this pin to the ground level. SIF IN (5.5 MHz) SIF IN (6.0 MHz) SIF IN (6.5 MHz) RF AGC VR A H H H H L L L L Switch B C H H H L L H L L H H L L H L L H 5.5 MHz 6.0 MHz 6.5 MHz 4.5 MHz ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● No. 5764-9/11 LA7566 Notes on Sanyo SAW Filters There are two types of SAW filters, which differ in the piezoelectric substrate material, as follows: 1. Lithium tantalate (LiTaO3) SAW filter TSF11 ■ ■ ■ ······ Japan TSF12 ■ ■ ■ ······ US Although lithium tantalate SAW filters have the low temperature coefficient of –18 ppm/°C, they suffer from a large insertion loss. However, it is possible, at the cost of increasing the number of external components required, to minimize this insertion loss by using a matching circuit consisting of coils and other components at the SAW filter output. At the same time as minimizing insertion loss, this technique also allows the frequency characteristics, level, and other aspects to be varied, and thus provides increased circuit design flexibility. Also, since the SAW filter reflected wave level is minimal, the circuit can be designed with a small in-band ripple level. 2. Lithium niobate (LiNbO3) SAW filter TSF52 ■ ■ ■ ······ US TSF53 ■ ■ ■ ······ PAL Although lithium niobate SAW filters have the high temperature coefficient of –72 ppm/°C, they feature an insertion loss about 10 dB lower than that of lithium tantalate SAW filters. Accordingly, there is no need for a matching circuit at the SAW filter output. Although the in-band ripple is somewhat larger than with lithium tantalate SAW filters, since they have a low impedance and a small field slew, they are relatively immune to influences from peripheral circuit components and the geometry of the printed circuit board pattern. This allows stable out-of-band trap characteristics to be acquired. Due to the above considerations, lithium tantalate SAW filters are used in applications for the US and Japan that have a high IF frequency, and lithium niobate SAW filters are used in PAL and US applications that have a low IF frequency. Notes on SAW Filter Matching In SAW filter input circuit matching, rather than matching the IF frequency, flatter video band characteristics can be acquired by designing the tuning point to be in the vicinity of the audio carrier rather than near the chrominance carrier. The situation shown in figure on the right makes it easier to acquire flat band characteristics than that in figure on the left. SAW filter characteristics The high-band is extended The high-band reduced Frequency Frequency With the tuning set to the IF frequency With the tuning set to the vicinity of S and C Coil Specifications JAPAN f = 58.75 MHz US f = 45.75 MHz PAL f = 38.9 MHz VCO coils SAW filters (split) SAW filters (inter) Test production No. 16991A Tokyo Parts Industrial Co., Ltd. Test production No. 16687A Tokyo Parts Industrial Co., Ltd. Test production No. 16686A Tokyo Parts Industrial Co., Ltd. Picture Picture Picture TSF1137U TSF1241 TSF5315 SOUND SOUND SOUND TSF5220 TSF5321 TSF5221 Tokyo Parts Industrial Co., Ltd. 236 Hinode Machi Isesaki Shi, Gunma Prefecture Japan TEL: +81-270-23-3731 TSF5344 No. 5764-10/11 LA7566 Notes on VCO Tank Circuits 1. Built-in capacitor VCO tank circuits When the power is turned on, the heat generated by the IC is transmitted through the printed circuit board to the VCO tank circuit. At this point, the VCO coil frame functions as a heat sink and the IC heat is dissipated. As a result, it becomes more difficult to transmit heat to the VCO tank cricuit's built-in capacitor, and the influence of drift at power on is reduced. Therefore, it suffices to design the circuit so that the coil and capacitor thermal characteristics cancel. Ideally, it is better to use a coil with a core material that has low temperature coefficient characteristics. 2. External capacitor VCO tank circuits When an external capacitor is used, heat generated by the IC is transmitted through the printed circuit board directly to the VCO tank circuit external capacitor. While this capacitor is heated relatively early after the power is turned on, the coil is not influenced as much by this heat, and as a result the power-on drift is increased. Accordingly, a coil whose core material has low temperature coefficient characteristics must be used. It is also desirable to use a capacitor with similarly low temperature coefficient characteristics. Note: Applications that use an external capacitor here must use a chip capacitor. If an ordinary capacitor is used, problems such as the oscillator frequency changing with the capacitor orientation may occur. ■ No products described or contained herein are intended for use in surgical implants, life-support systems, aerospace equipment, nuclear power control systems, vehicles, disaster/crime-prevention equipment and the like, the failure of which may directly or indirectly cause injury, death or property loss. ■ Anyone purchasing any products described or contained herein for an above-mentioned use shall: ➀ Accept full responsibility and indemnify and defend SANYO ELECTRIC CO., LTD., its affiliates, subsidiaries and distributors and all their officers and employees, jointly and severally, against any and all claims and litigation and all damages, cost and expenses associated with such use: ➁ Not impose any responsibility for any fault or negligence which may be cited in any such claim or litigation on SANYO ELECTRIC CO., LTD., its affiliates, subsidiaries and distributors or any of their officers and employees jointly or severally. ■ Information (including circuit diagrams and circuit parameters) herein is for example only; it is not guaranteed for volume production. SANYO believes information herein is accurate and reliable, but no guarantees are made or implied regarding its use or any infringements of intellectual property rights or other rights of third parties. This catalog provides information as of March, 1998. Specifications and information herein are subject to change without notice. PS No. 5764-11/11