Ordering number : EN3312 Monolithic Linear IC LA1065M 2 Tuner Diversity Circuit for Car FM Tuner Overview Package Dimensions The LA1065M is a multi-functional IC for 2 tuner diversity, and is capable of multi-path distortion detection with high sensitivity. unit: mm 3036B-MFP20 [LA1065M] Functions • Noise amplifier. • Noise AGC circuit. • Noise density comparison counting circuit. • MAIN/SUB switching output. • Weak electric field detection and antenna fixing circuit. • Very strong electric field detection and antenna fixing circuit. • S meter voltage comparison circuit. SANYO: MFP20 • AGC voltage output. • S meter switch. Specifications Maximum Ratings at Ta=25°C Parameter Maximum supply voltage Maximum flow-out current Maximum flow-in current Maximum applied voltage Symbol Conditions Ratings Unit VCC max I(4) 13 Pin 4 1 mA I(5) Pin 5 1 mA I(6) Pin 6 1 mA I(9) Pin 9 10 mA I(12) Pin 12 100 µA I(7) Pin 7 1 mA I(8) Pin 8 1 mA V(15) V(16) V(17) V(13) V(14) Ta=25°C V VCC VCC V VCC VCC V VCC 230 V V V Allowable power dissipation Pd max Operating temperature Topr –30 to +80 mW °C Storage temperature Tstg –40 to +125 °C SANYO Electric Co.,Ltd. Semiconductor Bussiness Headquarters TOKYO OFFICE Tokyo Bldg., 1-10, 1 Chome, Ueno, Taito-ku, TOKYO, 110 JAPAN 93097HA (KT)/2200TA, TS (AF) No.3312-1/8 LA1065M Operating Conditions at Ta=25°C Parameter Symbol Recommended supply voltage VCC Operating voltage range VCC op Conditions Ratings Unit 8 V 7 to 12 V Operation Characteristics at Ta=25°C, VCC=8V, f=100kHz sine wave Parameter Symbol Conditions Ratings min typ max Unit Current drain ICC No input, not including pin 9 current 10 16 22 Pin 9 high-level voltage V9H 1kΩ resistance between pin 9 and GND 5.0 6.0 7.5 V Noise amplifier gain Gsub Vsub in=10mVrms pin 6 output 33 36 39 dB Noise amplifier gain mA GV1 Vmain in=Vsub in=1mVrms pin 6 output 33 36 39 dB GV2 Vmain in=Vsub in=100mV pin 6 output 6 10 14 dB Noise detection sensitivity NDS Noise AGC off 8 12 16 mVrms Noise count number NCN Difference between MAIN and SUB noise Gate time 1 tG Noise AGC off 4 500 620 740 µs Repeat cycle of pin 4 waveform Pin 6 voltage V6 Vmain=Vsub=200mVrms Pin 5 voltage V5 Vsub=100mVrms 0.4 1.1 2.0 V 2.50 2.85 3.20 V Strong field detection level Medium field detection level V17 0.7 1.1 1.5 V V14 2.4 2.7 3.1 V Weak field detection level V13 S meter switch residual V12 1.7 2.1 2.4 V Input=0V 130 mVrms Equivalent Circuit Block Diagram No.3312-2/8 LA1065M Sample Application Circuit Unit (resistance : Ω, capacitance : F) Operating Principle (1) Multi-path distortion detection • Overview The LA1065M compares the high frequency noise elements in the S meter output from the two tuners to perform multi-path distortion detection. In addition to the higher harmonic distortion due to multi-path, the S meter noise includes pulse noise such as car engine ignition noise, distortion elements due to modulation, phase noise and so on. All of this noise causes misoperation of multi-path distortion detection. The LA1065M resolves this problem through use of a unique noise count comparison method and the bottom detection-type noise AGC. • Noise count comparison The causes of misoperation in a diversity reception system, which are pulse noise, distortion elements caused by modulation, and phase noise, exist almost equally for MAIN and SUB. Also, the multi-path distortion to be detected tends to exist on either the MAIN or SUB side. The LA1065M uses an up/down counter to compare the noise counts of MAIN and SUB and detect multi-path. • Bottom detection noise AGC As described above, the S meter noise also exists on both MAIN and SUB sides, so when there is noise on both sides, AGC goes on to prevent misoperation. On the other hand, when multi-path is generated and noise is on one side or the other, AGC does not go on, enabling high sensitivity detection. • A combination of the above methods is used to make the LA1065M capable of accurate multi-path detection. No.3312-3/8 LA1065M (2) S meter voltage comparison For a medium field, the sound may be better if the antenna is switched by comparing S meter DC voltage rather than using multi-path distortion detection when, for example, there is quite a difference (more than 10dB) in antenna sensitivity between MAIN and SUB. On the LA1065M, a built-in comparator detects the medium field, and compares S meter DC voltage in order to switch the antenna. (3) Weak field detection and antenna fixing (MAIN) There is a difference in antenna sensitivity between MAIN and SUB in a weak field, so sensitivity will be insufficient even if switched to SUB. The LA1065M uses a comparator, as shown below, to detect the weak field and fix the switching signal to the MAIN side. Unit (resistance : Ω) (4) Very strong field detection and antenna fixing (SUB) Interference such as I.M. (intermodulation) and cross modulation is generated in a very strong field. One countermeasure is to use a PIN diode for antenna damping, but here the lower antenna gain on the SUB side is utilized to fix the antenna to the SUB side when the electric field is strong. Also, with LA1065M, operation returns to normal when multi-path is generated. (5) AGC voltage output As described in the section on bottom detection-type noise AGC, AGC voltage goes high when there is a lot of noise on both MAIN and SUB sides. This voltage can be used to apply SNC, HCC and so on when the conditions are poor for both MAIN and SUB. (6) S meter switch The LA1065M has built-in S meter switch so that SNC can be applied according to the MAIN and SUB switching output. When the antenna is on MAIN, SNC is applied by MAIN side S meter voltage, and when it is on SUB, by SUB side meter voltage. (7) Logic section The LA1065M operation is shown in th table below. MAIN multiSUB multiMAIN S meter SUB S meter path detection path detection voltage voltage No noise * Strong field With noise With noise * Strong field No noise * * Weak field * MAIN>SUB Medium field * * MAIN<SUB Medium field * * No noise * Strong field * With noise * Strong field No noise * Strong field Large noise Medium noise * Strong field Small noise Medium noise * : Under any conditions FE AGC voltage Weak-medium field Weak-medium field * Weak-medium field Weak-medium field Very strong field Very strong field Very strong field Very strong field MAIN/SUB switching output SUB side MAIN side MAIN side MAIN side SUB side SUB side MAIN side SUB side MAIN side No.3312-4/8 LA1065M Unit (resistance : Ω, capacitance : F) Pin Function Pin No. Function External The AC component of 114kHz in IF, S meter output is taken by the BPF and input to pin 1 (or pin 20) by C coupling. Notes 1 (20) MAIN IN SUB IN 2 (19) H.P.F. Highpass filter 3 (18) AGC Increase this capacitor's value if antenna switching tends to misoperate. 4 Be advised that the LA1065M input impedance changes with input and can go to a minimum of 10kΩ. Monostable multi-vibrator Continued on next page. No.3312-5/8 LA1065M Unit (resistance : Ω, capacitance : F) Continued from preceding page. Pin No. Function 5 SUB noise detection for strong field 6 AGC voltage output 7 8 Multi-path detection mode switching External Notes DC voltage corresponding to the LA1065M AGC can be taken. Mode switching table Pin No. Pin 7 Pin 8 9 MAIN/SUB switching signal output GND Count method for strong field (4 counts) S meter comparison for medium field VCC S meter 114kHz level comparison for strong field Count method for medium field (8 counts) MAIN is high (6V typ when resistance bet-ween pin 9 and GND is 1kΩ) and SUB is low. Continued on next page. No.3312-6/8 LA1065M Unit (resistance : Ω, capacitance : F) Continued from preceding page. Pin No. Function 10 GND 11 VCC 12 S meter output 13 Comparator for weak field detection 14 Comparator for medium field detection 15 SUB S meter input 16 MAIN S meter input 17 F.E. AGC input External Notes S meter input must be sufficiently integrated before input. Comparison level is set at approximately 1V. No.3312-7/8 LA1065M 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 lose. Anyone purchasing any products described or contained herein for an above-mentioned use shall: 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: Not impose any responsibilty 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 September, 1997. Specifications and information herein are subject to change without notice. No.3312-8/8