Ordering number : EN6038A Monolithic Linear IC LA1781M For Car Radios Single-Chip Tuner IC Overview The LA1781M integrates all six blocks required in a car radio tuner on a single chip. Features • Improved noise reduction methods The FM front end provides excellent 3-signal characteristics equivalent to those of the LA1193M. Superlative listenability due to improved medium and weak field noise canceller characteristics. Improved separation characteristics. Anti-birdie filter. Improved AM and FM thermal characteristics. Excellent FM signal meter linearity. Modified N.C. circuit for improved noise rejection. • Double conversion AM tuner (up conversion) Reduces the number of external components required as compared to earlier double conversion tuners, in particular, no crystal is required (when used in conjunction with the LC72144). • Sample-to-sample variation reduction circuit built into the FM IF circuit. (Fixed resistors are used for the SD, keyed AGC, mute on adjustment, ATT, SNC, and HCC functions.) • The LA1781 inherits the block arrangement of the LA1780M and supports pin-compatible designs. Functions • FM front end • Multiplex • FM IF • AM up-conversion • Noise canceller • FM/AM switch • MRC Any and all SANYO Semiconductor Co.,Ltd. products described or contained herein are, with regard to "standard application", intended for the use as general electronics equipment (home appliances, AV equipment, communication device, office equipment, industrial equipment etc.). The products mentioned herein shall not be intended for use for any "special application" (medical equipment whose purpose is to sustain life, aerospace instrument, nuclear control device, burning appliances, transportation machine, traffic signal system, safety equipment etc.) that shall require extremely high level of reliability and can directly threaten human lives in case of failure or malfunction of the product or may cause harm to human bodies, nor shall they grant any guarantee thereof. If you should intend to use our products for applications outside the standard applications of our customer who is considering such use and/or outside the scope of our intended standard applications, please consult with us prior to the intended use. If there is no consultation or inquiry before the intended use, our customer shall be solely responsible for the use. Specifications of any and all SANYO Semiconductor Co.,Ltd. products described or contained herein stipulate the performance, characteristics, and functions of the described products in the independent state, and are not guarantees of the performance, characteristics, and functions of the described products as mounted in the customer' s products or equipment. To verify symptoms and states that cannot be evaluated in an independent device, the customer should always evaluate and test devices mounted in the customer' s products or equipment. 71509 SY PC/32301TN (OT) No.6038-1/48 LA1781M Specifications Maximum Ratings at Ta = 25°C Parameter Symbol Conditions Ratings Pins 6, 40, and 61 Unit Maximum supply voltage VCC1 max 9 V VCC2 max Pins 7, 45, 54, 59, and 60 Allowable power dissipation Pd max Ta ≤ 55°C Operating temperature Topr -40 to +85 °C Storage temperature Tstg -40 to +150 °C 12 V 950 mW Operating Conditions at Ta = 25°C Parameter Recommended supply voltage Operating supply voltage range Symbol Conditions Ratings Unit VCC Pins 6, 7, 40, 45, 54, 59, 60, and 61 8 V VCCST IND Pin 26 5 V 7.5 to 9.0 V VCC op Electrical Characteristics at Ta = 25°C, VCC = 8V, in the specified test circuit for the FM IF input Parameter Symbol Ratings Conditions min typ Unit max FM characteristics At the FM IF input Current drain ICCO-FM No input, I40 + I45 + I54 + I59 + I60 + I61 60 94 110 mA Demodulation output VO-FM 10.7MHz, 100dBμ, 1kHz, 100%mod, The pin 15 output 205 310 415 mVrms Pin 31 demodulation output VO-FM31 10.7MHz, 100dBμ, 1kHz, 100%mod, The pin 31 output 190 295 380 mVrms 0 +1 dB 0.3 1.0 Channel balance CB The ratio between pins 15 and 16 at 10.7MHz, 100dBμ, 1kHz Total harmonic distortion THD-FM mono 10.7MHz, 100dBμ, 1kHz, 100% mod, pin 15 Signal-to-noise ratio : IF S/N-FM IF 10.7MHz, 100dBμ, 1kHz, 100% mod, pin 15 75 AM suppression ratio: IF AMR IF 10.7MHz, 100dBμ, 1kHz, fm = 1kHz, 30% AM, pin 15 55 68 Muting attenuation Att-1 10.7MHz, 100 dBμ, 1kHz. The pin 15 attenuation when V33 goes from 0 to 2V 5 10 15 dB Att-2 10.7MHz, 100 dBμ, 1kHz. The pin 15 attenuation when V33 goes from 0 to 2V*1 15 20 25 dB Att-3 10.7MHz, 100 dBμ, 1kHz. The pin 15 attenuation when V33 goes from 0 to 2V*2 28 33 38 dB 10.7MHz, 100dBμ, L + R = 90%, pilot = 10%. The pin 15 output 30 40 Separation Sep -1 82 % dB dB dB ratio Stereo on level ST-ON The pilot modulation such that V26 < 0.5V 2.1 4.1 Stereo off level ST-OFF The pilot modulation such that V26 > 3.5V 1.2 3.1 Main total harmonic distortion THD-Main L 10.7MHz, 100dBμ, L + R = 90%, pilot = 10%. The pin 15 signal Pilot cancellation PCAN 10.7MHz, 100dBμ, pilot = 10%. The pin 15 signal/the pilot level leakage. DIN audio SNC output attenuation AttSNC 10.7MHz, 100dBμ, L - R = 90%, pilot = 10%. V28 = 3V → 0.6V, pin 15 HCC output attenuation AttHCC-1 0.3 6.5 % % 1.2 % 20 30 1 5 9 dB 10.7MHz, 100dBμ, 10kHz, L + R = 90%, pilot = 10%. V29 = 3V → 0.6V, pin 15 0.5 4.5 8.5 dB AttHCC-2 10.7MHz, 100dBμ, 10kHz, L + R = 90%, pilot = 10%. V29 = 3V → 0.1V, pin 15 6 10 14 dB Input limiting voltage VIN-LIM 100dBμ, 10.7MHz, 30% modulation. The IF input such that the input reference output goes down by 3dB 33 40 47 dBμ Muting sensitivity VIN-MUTE The IF input level (unmodulated) when V33 = 2V 27 35 43 dBμ SD sensitivity SD-sen1 FM The IF input level (unmodulated) (over 100mV rms) such that the IF counter buffer output goes on 54 62 70 dBμ 54 62 70 dBμ IF counter buffer output VIFBUFF-FM 10.7MHz, 100dBμ, unmodulated. The pin 23 output 130 200 270 mVrms Signal meter output VSMFM-1 No input. The pin 24 DC output, unmodulated 0.0 0.1 0.3 V VSMFM-2 50dBμ. The pin 24 DC output, unmodulated 0.4 1.0 1.5 V SD-sen2 FM dB VSMFM-3 70dBμ. The pin 24 DC output, unmodulated 2.0 2.7 3.5 V VSMFM-4 100dBμ. The pin 24 DC output, unmodulated 4.7 5.5 6.2 V Muting bandwidth BW-MUTE 100dBμ. The bandwidth when V33 = 2V, unmodulated 150 220 290 kHz Mute drive output VMUTE-100 100dBμ, 0dBμ. The pin 33 DC output, unmodulated 0.00 0.03 0.20 V Continued on next page. No.6038-2/48 LA1781M Continued from preceding page. Parameter Symbol Ratings Conditions min typ Unit max FM FE Mixer input N-AGC on input VNAGC 83MHz, unmodulated. The input such that the pin 2 voltage is 2.0V or below 81 88 95 dBμ W-AGC on input VWAGC 83MHz, unmodulated. The input such that the pin 2 voltage is 2.0V or below. (When the keyed AGC is set to 4.0V.) 104 110 116 dBμ Conversion gain A. V 83MHz, 80dBμ, unmodulated. The FE CF output 19 30 48 mVrms Oscillator buffer output VOSCBUFF-FM No input 85 110 165 mVrms NC Block NC input (pin 30) Gate time TGATE f = 1kHz, for a 1μs, 100-mVp-o pulse 55 μs Noise sensitivity SN The level of a 1kHz, 1μs pulse input that starts noise canceller operation. Measured at pin 30. 40 mVp-o NC effect SN-NC The pulse rejection effect provided by the noise canceller. For a repeated 1μs wide pulse, frequency = 10kHz, 5 150mVp-o. The ratio of the FM mode pin 15 output referenced to the AM mode pin 15 output (effective value) Multipath rejection circuit MRC input (pin 27) MRC output VMRC V24 = 5V 2.2 2.3 2.4 V MRC operating level MRC-ON The pin 32 input level at f = 70kHz such that pin 24 goes to 5V and pin 27 goes to 2V 10 15 20 mVrms AM characteristics AM ANT input Practical sensitivity S/N-30 1MHz, 30dBμ, fm = 1kHz, 30% modulation, pin 15 20 Detector output VO-AM 1MHz, 74dBμ, fm = 1kHz, 30% modulation, pin 15 130 195 270 mVrms dB Pin 31 detector output VO-AM31 1MHz, 74dBμ, fm = 1kHz, 30% modulation, pin 31 110 175 230 mVrms AGC F.O.M. VAGC-FOM 1MHz, 74dBμ, referenced to the output, the input amplitude such that the output falls by 10dB. Pin 15 59 64 69 dB Signal-to-noise ratio S/N-AM 1MHz, 74dBμ, fm = 1kHz, 30% modulation 47 52 Total harmonic distortion THD-AM 1MHz, 74dBμ, fm = 1kHz, 80% modulation 0.3 1 Signal meter output VSMAM-1 No input 0.0 0.2 0.5 V VSMAM-2 1MHz, 130dBμ, unmodulated 3.5 4.4 6.1 V dB % Oscillator buffer output VOSCBUFF-AM1 No input, the pin 15 output 185 230 Wide band AGC sensitivity W-AGCsen1 1.4MHz, the input when V46 = 0.7V 92 98 104 dBμ W-AGCsen2 1.4MHz, the input when V46 = 0.7V (seek mode) 83 89 95 dBμ 1MHz, the ANT input level such that the IF counter output turns 24 30 36 dBμ 24 30 36 dBμ 200 290 SD sensitivity SD-sen1AM mVrms on. SD-sen2AM 1MHz, the ANT input level such that the SD pin goes to the on state. IF buffer output VIFBUFF-AM 1MHz, 74dBμ, unmodulated. The pin 23 output mVrms Note : These measurements must be made using the either the IC-51-0644-824 or KS8277 IC socket (manufactured by Yamaichi Electronics). *1. When the resistor between pin 58 and ground is 200kΩ. *2. When the resistor between pin 58 and ground is 30kΩ. No.6038-3/48 LA1781M Package Dimensions 48 0.8 17.2 14.0 33 14.0 64 17.2 32 49 17 1 16 0.8 0.35 0.15 1000 950 900 800 Pd max -- Ta Mounted on a specified board : 40 × 80 × 1.3mm3 glass epoxy board 700 Independent IC 600 500 400 300 200 100 0 --40 --20 0 20 40 60 80 100 Ambient temperature, Ta -- °C 0.1 3.0max (2.7) (1.0) Allowable power dissipation, Pd max -- mW unit : mm (typ) 3159A SANYO : QIP64E(14X14) Function List 1. FM Front End (Equivalent to the Sanyo LA1193) (1) Double input type double balanced mixer (2) Pin diode drive AGC output (3) MOSFET second gate drive AGC output (4) Keyed AGC adjustment pin (5) Differential IF amplifier (6) Wide band AGC sensitivity setting pin, and narrow band AGC sensitivity setting pin (7) Local oscillator 2. FM IF (1) IF limiter amplifier (2) S-meter output (also used for AM) 6-stage pickup (3) Multipath detection pin (shared FM signal meter) (4) Quadrature detection (5) AF preamplifier (6) AGC output (7) Band muting (8) Weak input muting (9) Soft muting adjustment pin (10) Muting attenuation adjustment pin (11) IF counter buffer output (also used for AM) (12) SD (IF counter buffer on level) adjustment pin (13) SD output (active high) (also used for AM) 3. Noise Canceller (1) High-pass filter (first order) (2) Delay circuit based low-pass filter (fourth order) (3) Noise AGC (4) Pilot signal compensation circuit (5) Noise sensitivity setting pin (6) Function for disabling the noise canceller in AM mode 4. Multiplex Functions (1) Adjustment-free VCO circuit (2) Level follower type pilot canceller circuit (3) HCC (high cut control) (4) Automatic stereo/mono switching (5) VCO oscillation stop function (AM mode) (6) Forced monaural (7) SNC (stereo noise controller) (8) Stereo display pin (9) Anti-birdie filter 5. AM (1) Double balanced mixer (1st, 2nd) (2) IF amplifier (3) Detection (4) RF AGC (narrow/wide) (5) Pin diode drive pin (6) IF AGC (7) Signal meter output (also used for FM) (8) Local oscillator circuits (first and second) (9) Local oscillator buffer output (10) IF counter buffer output (also used by the FM IF) (11) SD (IF counter buffer on level) adjustment pin (12) SD output (active high) (also used for AM) (13) Wide AGC (14) Detection output frequency characteristics adjustment pin (low cut, high deemphasis) (15) AM stereo buffer 6. MRC (multipath noise rejection circuit) 7. AM/FM switching output (linked to the FM VCC) No.6038-4/48 LA1781M Operating Characteristics and Symbols Used in the Test Circuit Diagrams (1) Switches (SW) Switch on = 1, SW off = 0 There are two switches that use signal transfer. 1) SW2 : switches between the mixer input and the IF input. 2) SW4 : switches between noise canceler input and IF output + noise canceler input. (2) Types of SG used PG1 (AC1) Used for noise canceler testing. A pulse generator and an AF oscillator are required. AC2 Used for FM front end testing. Outputs an 83MHz signal. AC3 Used for FM IF, noise canceler, and MPX testing. Outputs a 10.7MHz signal. Stereo modulation must be possible. AC4 Used for AM testing. Outputs 1 MHz and 1.4MHz signals. AC5 Used with the MRC. Can also be used for AF and OSC. (3) Power supply VCC 8V VCC1 5V VCC2 0.1V/0.7V/2V/4V These levels must be Keyed AGC, Mute ATT VCC3 0.1V/0.6V/2V variable. HCC, SNC, SASC (MRC) SD, stereo, seek/stop (4) (a) Switches Parameter ON SW1 AM/FM switching. The FE VCC is supplied to pin 62. SW2 FM IF switching. Pin 51/FE output SW3 For conversion gain testing SW4 For switching between noise canceler input and IF output + noise OFF FM AM FE IF OUT (A) AC3 (B) Conversion gain measurement (A) Other/purposes AC1 (A) Other/purposes canceler. SW5 High-speed SD SW6 SEEK/STOP (IF BUFF ON/OFF) High-speed SD Other/purposes STOP Seek (IF buffer output) SW7 SW8 MUTE ATT 200kΩ MUTE 200kΩ OFF MUTE ATT 30kΩ MUTE 30kΩ SW9 For pilot cancellation testing OFF When pilot cancellation is used When pilot cancellation is not used SW10 Mute off (pin 33) MUTE OFF MUTE ON (b) Trimmers (variable resistors) VR1 Separation adjustment VR2 Pilot cancellation adjustment (5) Test Points (a) DC voltages VD1 FM RF AGC voltage Pin 2 VD2 AM/FM SD, AM Tweet, FM stereo indicator Pin 26 VD3 AM/FM S-meter Pin 24 VD4 MRC output Pin 27 VD5 Mute drive output Pin 33 VD6 AM antenna damping voltage Pin 46 VD7 N.C. Gate time Pin 8 (b) AC voltages VA1 AM/FM OSC Buff Pin 4 VA2 First IF output Pin 53 → CF → pin 51 load level (10.7MHz) VA3 IF counter buffer Pin 23 (10.7MHz/450kHz) VA4 MPX OUT Left ch Pin 15 (AF) VA5 MPX OUT Right ch Pin 16 (AF) No.6038-5/48 LA1781M Pin Descriptions Pin No. 1 Pin function Antenna damping drive Pin description Equivalent circuit An antenna damping current flows VCC when the RF AGC voltage (pin 2) Pin 62 ANT RF AGC reaches VCC - VD. 1000pF 300Ω 100Ω 1 100Ω 1000pF 2 RF AGC Used to control the FET VCC second gate. FET 2ND GATE + 12kΩ 2 DAMPING DRIVER ANT N AGC DET W AGC DET VCC KEYED AGC 3 F.E.GND 4 OSC Oscillator connection. VCC The transistor and capacitors required for the oscillator circuit are integrated on the chip. 4 25pF 2kΩ VT 7 AM OSC AM first oscillator. 20pF 7 This circuit can oscillator up to the VCC SW band. An ALC circuit is included. A L C Continued on next page. No.6038-6/48 LA1781M Continued from preceding page. Pin No. Pin function 8 Noise AGC sensitivity 9 AGC adjustment Pin description Equivalent circuit After setting up the medium field (about 50dBμ) sensitivity with the noise sensitivity setting pin (pin 8), set 3kΩ the weak field (about 20 to 30dBμ) sensitivity with the AGC adjustment 15kΩ 3kΩ pin (pin 9). 200Ω 8 9 3kΩ + 1MΩ 0.01μF 11 Memory circuit connection 12 Recording circuit used during noise 0.01μF 6800pF 3.9kΩ canceller operation. 13 12 0.47μF 11 VCC Differential amp Gate circuit LPF 13 Pilot input Pin 13 is the PLL circuit input pin. VCC 30kΩ PLL N.C 12 13 0.01μF 14 N.C, MPX, MRC, GND Ground for the N.C., MPX, and MRC circuits. Continued on next page. No.6038-7/48 LA1781M Continued from preceding page. Pin No. Pin function Pin description 15 MPX output (left) Deemphasis 16 MPX output (right) 50μs : 0.015μF Equivalent circuit VCC 75μs : 0.022μF 3.3kΩ 3.3kΩ 15 16 0.015μF 17 Pilot canceller signal output Adjustment is required since the pilot 0.015μF VCC signal level varies with the sample-to-sample variations in the IF output level and other parameters. 20kΩ 6.7kΩ 10kΩ 17 18 0.01μF 18 Pilot canceller signal output Pin 18 is the output pin for the pilot 100kΩ VCC canceller signal. 1.5kΩ 17 18 0.01μF 100kΩ 19 Separation Use a trimmer to adjust the adjustment pin subdecoder input level. Composit signal DECODER 5kΩ (The output level is not modified in mono and main modes.) 19 30kΩ 0.047μF Continued on next page. No.6038-8/48 LA1781M Continued from preceding page. Pin No. 20 Pin function VCO Pin description Equivalent circuit The oscillator frequency is 912Hz. CSB 912 JF104 KBR-912F108 (Kyocera Corporation) 20 CSB-912JF108 VREF (Murata Mfg. Co., Ltd.) 10pF 21 PHASE COMP. 22 PHASE COMP. VREF 15kΩ + 15kΩ 19kΩ 22 + + 21 23 IF counter buffer seek/stop This pin functions both as the IF switching counter buffer (AC output) and as the 4.9V seek/stop switch pin. The voltage V23 switches between the following three modes. During FM reception : 5V : Seek mode + -- 50kΩ + -- 1.3V VCC IF counter buffer 10kΩ SW + -- 150Ω 2.5V : Forced SD mode 0V : AM MUTE 50F Reception mode AM reception (two modes : 0 and 5V) 5V : Seek mode 0V : Reception mode SD circuit 23 51kΩ STOP IF BUFF. Forced SD:2.5V SEEK 5V Continued on next page. No.6038-9/48 LA1781M Continued from preceding page. Pin No. 24 Pin function AM/FM signal meter Pin description Equivalent circuit Fixed-current drive signal meter VCC output. 32 Dedicated FM signal meter In AM mode, pin 32 outputs a 1mA current. Thus the HCC FM S-meter circuit is turned off. 32 10kΩ AM S-meter 24 10kΩ AM/FM SW Outputs a 1-mA current during AM reception 26 Stereo indicator for the SD pin AM/FM SW MRC The voltage V23 switches between three modes as follows. FM reception : 5V : The SD pin operates linked to the IF counter buffer. AM/FM SD 2.5V : Forced SD mode: operates Stereo indicator as the SD pin. Seek/stop switching 0.7V : Reception mode: stereo indicator 26 AM reception : (two modes : 0 and 5V) 27 5V : Operates as the seek SD pin. 0V : Reception mode. Not used. MRC control voltage time The MRC detector time constant is constant determined by a 100Ω resistor and C2 when discharging and by the 2μA 100kΩ VDD VCC VCC 2μA C2 + current and C2 when charging. 27 100Ω Pin 28 28 SNC control input The sub-output is controlled by a 0 to VREF 1V input. 28 Continued on next page. No.6038-10/48 LA1781M Continued from preceding page. Pin No. 29 Pin function HCC control input Pin description Equivalent circuit The high band frequency output is VREF controlled by a 0 to 1V input. It can also be controlled by the MRC output. Use a resistor of at least 100kΩ when controlling with the pin 32 FM S-meter signal. 32 29 + 1μF 30 Noise canceller input Pin 30 is the noise canceller input. VCC The input impedance is 50kΩ. 31 AM/FM detector output Pin 31 is the AM and FM detector FM detector output 31 output In FM mode, this is a low-impedance 10kΩ output. In AM mode, the output impedance is VCC 10kΩ. To improve the low band separation, use a coupling capacitor of over 10μF. 1μF AM detector + 30 Noise canceller 50kΩ 4.2V 32 IF S-meter output and MRC FM S-meter output block DC input MRC AC input block VCC Adjust the external 1kΩ resistor to attenuate the MRC AC input and control the circuit. 32 10kΩ + 1μF 1kΩ MRC input Continued on next page. No.6038-11/48 LA1781M Continued from preceding page. Pin No. 33 Pin function Mute drive output Pin description Equivalent circuit •The muting time constant is C1 determined by an external RC circuit + as described below. 0.1μF Attack time : TA = 10kΩ × C1 Release time : TR = 50kΩ × C1 •Noise convergence adjustment 33 VCC The noise convergence can be 50kΩ adjusted when there is no input MUTE AMP. signal by inserting a resistor between pin 33 and ground. SEEK OFF 10kΩ •Muting off function Ground pin 33 through a 4kΩ resistor. SOFT MUTE HOLE DET Band muting 50kΩ SD circuit •The resistor R1 determines the width 34 AGC 35 QD output 36 QD input Increasing the value of R1 narrows 37 VREF the band. 0.1μF of the band muting function. R1 VREF VCC C Reducing the value of R1 widens the band. 37 •Null voltage R2 36 35 34 VCC When tuned, the voltage between pins 34 and 37, V34 - 37, will be 0V. Quadrature detector The band muting function turns on when |V34 - 37| ≥ 0.7V. HOLE DET 3pF 390Ω V37 = 4.9V 1kΩ IF limiter amplifier Band muting 38 FM SD ADJ A 130μA current flows from pin 38 R and, in conjunction with the external SD ADJ resistance R, determines the comparison voltage. 38 130μA + -- SD Comparator 24 S-meter Continued on next page. No.6038-12/48 LA1781M Continued from preceding page. Pin No. 39 Pin function Pin description Keyed AGC The keyed AGC operates when the AM stereo buffer voltage created by dividing the pin 24 Equivalent circuit 24 S-meter S-meter output voltage by the 6.4 and 6.4kΩ 3.6kΩ resistors becomes lower than the voltage determined by the resistor 3.6kΩ between pin 39 and ground. Comparator This pin also is used as the AM stereo KEYED AGC IF buffer pin. + -- 39 90μA 1.3V VCC AM IF out 41 HCC capacitor 50pF 150Ω The HCC frequency characteristics are determined by the external VCC capacitor connected at this pin. 20kΩ + 20kΩ 41 2200pF 42 AM L.C. pin This pin is used to change the VCC frequency characteristics of the unneeded audio band under 100Hz in C AM mode to produce a clear audio 42 signal. VCC Note : The LC capacitor must be connected between this pin DET and VCC (pin 40). 50kΩ 1kΩ This is because the detector + -- circuit operates referenced to 50kΩ VCC. The cutoff frequency fC is determined 1kΩ by the following formula. fC = 1/2π × 50kΩ × C 43 Pilot detector Inserting a 1MΩ resistor between pin VCC 43 and VCC will force the IC to mono mode. 19kHz∠0° BIAS 30kΩ 30kΩ + 30kΩ 43 1μF + Continued on next page. No.6038-13/48 LA1781M Continued from preceding page. Pin No. 44 Pin function IF AGC Pin description Equivalent circuit G1 ; Used for time constant switching VCC C 2.2μF + during seeks. 0.022μF • Reception 240kΩ τ = 2.2μF × 300kΩ 42 • Seek 44 VCC τ = 2.2μF × 10Ω The external capacitors are DET 50kΩ connected to VCC. This is because the IF amplifier operates referenced to VCC. 50kΩ IF AGC G1 SEEK ON 10Ω 45 IF output The IF amplifier load Pin 40 VCC 45 Pin 40 VCC DET 46 AM antenna damping I46 = 6mA (maximum) drive output This is the antenna damping Wide band AGC input current. VCC 50pF 46 100Ω 20kΩ VCC W.AGC AMP. ANT DAMPING DRIVER FM muting on level adjustment Modify the value of the external 30kΩ resistor to adjust the muting on level. R 47 VCC 140μA Pin 24 + -- 47 Inverter MUTE Continued on next page. No.6038-14/48 LA1781M Continued from preceding page. Pin No. Pin function Pin description 48 RF AGC bypass RF AGC rectification capacitor 57 RF AGC The low frequency distortion is Equivalent circuit VCC determined as follows : Increasing C48 and C57 improves the 5.6V 10kΩ distortion but makes the response slower. Reducing C48 and C57 aggravates the distortion but makes the response faster. 48 Antenna damping + -- + 3.3μF For AGC use 57 + 47μF 50 IF bypass Due to the high gain of the limiter 51 FM IF input amplifer, care must be taken when 2.6V choosing the grounding point for the limiter amplifer input capacitor to 10kΩ 10kΩ prevent oscillation. 50 0.022μF 330Ω 51 IF in 52 IF input The input impedance is 2kΩ. 2kΩ 100Ω 52 53 IF amplifier output 56 IF amplifier input • Input and output pin or the first IF VCC amplifier • Inverting amplifier V56 = 2V IF OUT 53 Input impedance : RIN = 330Ω 300Ω V53 = 5.3V 300Ω Output impedance 2.75V ROUT = 330Ω IF IN 56 Continued on next page. No.6038-15/48 LA1781M Continued from preceding page. Pin No. Pin function Pin description 54 Mixer output : 130μA The mixer coil connected to the pin 54 49 Mixer input mixer output must be wired to VCC Equivalent circuit Pin 40 VCC (pin 40). Pin 40 VCC The pin 49 mixer input Impedance is 330Ω 54 OSC 49 330Ω 55 W-AGC IN Pins 55 and 58 include built-in DC cut AM SD ADJ capacitors. The AGC on level is determined by 58 N-AGC IN the values of the capacitors C1 and Muting attenuation C2. W-AGC Pin 62 VCC N-AGC adjustment pin Pin 55 functions as the SD sensitivity adjustment pin in AM mode. 55 The output current I55 is 50μA, and 30pF C1 V55 varies depending on the value of 50pF the external resistor. The SD function operates by comparing V55 with the S-meter MIX IN 58 C2 voltage. 50μA + -- MIX OUT AM SD Signal meter 59, 60 Mixer output Double balanced mixer. 63, 64 Mixer input Pins 59 and 60 are the mixer 1ST.IF O S C 10.7MHz output 59 Pins 63 and 64 are the mixer input. This is an emitter insertion type circuit, and the amount of insertion is VCC 60 determined by the capacitors C1 and 30Ω C2. Note :The lines for pins 63 and 64 VCC must be kept separated from C1 the lines for pins 59 and 60. 63 RF AMP 5pF C2 64 5pF 620Ω 620Ω Continued on next page. No.6038-16/48 LA1781M Continued from preceding page. Pin No. 6 Pin function Pin description Front end VCC AM/FM Pin 6 functions both as the FM front switching end VCC and the AM/FM switching circuit. Equivalent circuit VCC SD 510Ω 6 + -- + V6 voltage AM/FM switching circuit Mode FM.F.E AGC 100kΩ When 8V → FM OPEN → AM 3.3V 8V 3 GND 62 1st MIX First mixer input INPUT The input impedance is about 10kΩ. AM 1st MIX to RF Amp. 62 10kΩ 2.1V 10 AM 2nd OSC Crystal oscillator circuit The Kinseki, Ltd. HC-49/U-S and 10kΩ a CL of 20pF must be used. 5.6V 20pF to 2nd MIX 33pF 10 X tal No.6038-17/48 LA1781M Block Diagram VCC 0.022μF TO AM STEREO (IF OUT) 40 39 0.47μF 38 37 ANT D 49 36 220Ω 51 52 + W.B.AGC 59 RF AGC SD/ST IND MAIN HC AMP BUFF AM 1ST OSC + 19 SEP.ADJ FF 18 SUB MAT DEC RIX COUNTER 100kΩ 17 300pF 10.26MHz NC MPX GND 10μF 10μF + + 0.022μF 0.022μF AM/FM OSC BUFF 22kΩ 4.7kΩ 51kΩ 22kΩ 240kΩ 240kΩ 2.2kΩ 68pF 1kΩ 10kΩ R L 10μF 10μF 200kΩ 18pF + 15 16 MPX OUT + 14 22kΩ 10 11 12 13 AM OSC 6800pF 0.01μF + FMIF AM GND 10pF 5pF 9 FM/AM VSM 30kΩ + 8 0.015μF 7 0.015μF 6 0.47μF 5 18pF 0.01μF 1MΩ 4 10kΩ FE GND RF AGC 1μF 3 30kΩ 1μF + 2.2kΩ 0.22μF 0.047μF 20kΩ FF 38k<0 0.22μF 100kΩ 10kΩ 10μF 3SK583 19 18 17 16 15 VSS PD VDD FM IN AM IN 14 100pF +B 12V 13 12 1.5kΩ 11 + 5.6V 22kΩ 20 100pF 100kΩ 22pF 100pF 100μF 100pF 0.22μF 51kΩ 7.2MHz DO 5 6 7 8 9 FM/AM 10 1kΩ + 9.1V 22kΩ CL 4 100kΩ CI 3 100μF CE 2 10kΩ 1 10kΩ LC7216M 22pF 1kΩ 0.01μF + 100kΩ P-CAN -- + GATE 0.022μF 18pF 30kΩ ANT D 2 FM GND FM/AM VT AMP PICAN INPUT TRIG GND 10kΩ TRIG 1μF CSB912JF104 0.01μF PI.CAN ADJ 1 100Ω 0.022μF LPF 21 ANT D 200kΩ 0.1μF AGC OSC 0.022μF 63 5pF 64 100kΩ 180W 3SK263 100kΩ 9pF GND 30kΩ + PILOT DET 20 NOISE AMP BUFF 5pF 5V 5.6kΩ 22 + AM/FM 8pF 1000pF 100kΩ 100F 0.022μF 39pF 100kΩ 1000pF VCO INPUT HPF SEEK→AM/FM SD STOP→FM ST IND. 23 FF 19k<0 61 0.022μF 62 22pF 22pF 24 PHASE COMP MIX FEVCC 1000pF FF 19k<90k VCO STOP GND AM/FM S-METER 0.47μF RIGHT CH. 330Ω SEEK SW 60 30Ω 10kΩ 26 KEYED AGC VCC 30Ω VCC SNC HCC 25 58 1μF HCC 1μF 62pF MUTE ATT 8200pF AM HC 27 56 57 50kΩ AM LEVEL ADJ NC-IN SNC IF AM/FM REG SW TWEET + + RF AGC WB AGC 55 0.022μF 2kΩ 28 MRC MIX FM WB AGCIN 200kΩ METER DET OUT IF BUFF AM FM VREF 300Ω 29 DC-C AFC DET CLAMP L.C. 53 FE IF IN FM ANT IN 0.47μF MUTE DRIVE 54 1000pF AFC IN 30 FMVSM FM SD AMVSM AM SD IF AGC DET AM SD ADJ AM MIX OUT 20kΩ 31 BUFF HOLE DET 1kΩ 100kΩ FM 22kΩ AM IF IN Q.DET IF limiter amplifier 100Ω 510kΩ 32 MUTE AMP N.C.MPX GND 15pF 15pF 47μF 100kΩ + 0.022μF OSC OSC BUFF 50 FM IF OUT AM RF GND MUTE DRIVE 1μF 33 34 FMIF AM NC MPX VCC FM IF IN ANTD 0.022μF AM ANT IN 35 LEFT CH. FC18 100μH AM VCC QD OUT QD IN VREF 0.22μF 100μF 41 100kΩ 42 GND 43 6.8kΩ KEYED AGC 30kΩ FM SD ADJ. AM LC 2200pF 0.022μF 1μF 44 + + 45 10kΩ 1μF 100μH 0.022μF 2.2μF 46 0.1μF + 47 + + 10kΩ 1MH 620Ω 30MH + 240kΩ RFAGC 48 0.022μF + IF7 + CHCC 30Ω 0.022μF 11kΩ 3.3μF PILOT DET GND 100pF CE CI CL DO RDS ADC MUTE SD/MONO ST R ON LC867148 No.6038-18/48 AC2 SG2 VD6 JIS DUMMY 15pF 65pF 100μH 6.8MH 50Ω 30Ω 0.022μF SW8 30kΩ 50Ω FC18 620Ω 100kΩ 47μF AC1 SG1 SW7 ANTD 0.022μF 200kΩ 0.022μF + 50Ω VCC VD1 0.022μF 0.022μF FM IF OUT AM IF IN 3pF VCC 100Ω 0.022μF 100Ω 1kΩ 5pF 5pF 64 63 62 61 60 59 58 57 56 GND FEVCC MUTE ATT 10pF FE IF IN FM WB AGCIN 55 54 53 52 51 FM IF IN 50 0.022μF + 1 ANT D AM/FM 2 + + 3 BUFF RF AGC 44 + L.C. 4 5 VA1 20pF OSC BUFF AM 1ST OSC KEYED AGC AM FM VREF 7 6 8V SW1 20kΩ TRIG AGC + 40 0.22μF -- + LPF 38 MAIN HC VCO STOP HCC SNC HOLE DET FF FF 38k<0 FF 19<0 FF 19<90 k MRC 3pF VCC 14 VCO 15 16 MPX OUT SUB MA DEC TRIX P-CAN 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 1μF + 0.22μF VR2 0.01μF PI.CAN ADJ 100kΩ SEP.ADJ VR1 SW9 0.047μF 20kΩ 1μF CSB912JF104 + 5.6kΩ 3pF B AM LEVEL ADJ 8200pF AM HC AM/FM S-METER 0.47μF GND SNC HCC NC-IN + DET OUT FM S-METER MUTE DRIVE 33 + TRIG PHASE COMP 34 + PILOT DET VA7 + VA6 10μF VA9 8V 0.022μF 0.47μF AFC IN MUTE DRIVE MUTE AMP 35 DC-C AFC DET CIAMP Q.DET 36 10kΩ 37 0.1μF VREF 10 11 12 13 AM OSC 6800pF 0.01μF + 39 QD IN + 10μF SW10 10.26MHz X TAL VCC 8 GATE HPF 9 FMVSM FM SD IF limiter amplifier 41 IF BUFF AMVSM AM SD 42 FF FM/AM REG SW TWEET IF DET AGC BUFF 0.022μF 240kΩ + 43 PILOT DET 1μF OSC OSC BUFF 45 RF AGC W.B. AGC ANT D 46 IF7 W.B.AGC VT 47 MIX MIX RFAGC 48 49 SW3 330Ω AM SD ADJ AM MIX OUT 0.022μF 1000μF 25Ω 300kΩ 510Ω 100μH 20kΩ 1MH 30Ω 330Ω 30Ω 39pF 100kΩ 50Ω 300Ω 200Ω 0.022μF IF IN B SW2(i) MIX A FM GND 300Ω 1μF 50Ω FM VCC 3.3μF ANT D 15kΩ RF AGC MUTE OR ADJ FE GND 30kΩ AC3 SG3 5pF QD OUT AM LC 300pF 100μF 0.01μF 10kΩ 1MΩ 2.2μF AM/FM OSC BUFF 2200pF CHCC 10kΩ 0.022μF 0.022μF 0.47μF VA2 1MΩ 1μF 10kΩ 0.015μF 6.8kΩ KEYED AGC 22kΩ FM SD ADJ. 10kΩ SW4(T) A 1μF MRC-IN 4.3kΩ VD5 8V VCC 8V 0.022μF SW5 50kΩ VCC3 PG1 (AC1) AC5 VCC2 VA3 SW6 VA8 VD3 VCC2 SEEK→AM/FM SD STOP→AM ST BUFFER FM ST IND. VD2 VD4 SNC HCC NC-IN FM/AM IFBUFF. 50kΩ 100kΩ IF OUT 10kΩ 0.022μF 10kΩ VCC N.C.MPX GND 0.1μF 0.015μF + LEFT CH. + RIGHT CH. + 1MΩ + 100kΩ + + 100kΩ GND 5V VCC1 LA1781M AC Characteristics Test Circuit + + No.6038-19/48 LA1781M Test Conditions Parameter Symbol Switch states SW1 SW2 SW3 SW4 SW5 SW6 SW7 SW8 SW9 SW10 Current drain ICCO-FM ON b OFF b - ON OFF OFF ON - Demodulation output VO-FM ON b OFF b - ON OFF OFF ON - Pin 31 demodulation output VO-FM31 ON b OFF b - ON OFF OFF ON - Channel balance CB ON b OFF b - ON OFF OFF ON - Total harmonic distortion (FM) THD-FM mono ON b OFF b - ON OFF OFF ON - Signal-to-noise ratio : IF S/N-FM IF ON b OFF b - ON OFF OFF ON - AM suppression ratio : IF AMR IF ON b OFF b - ON OFF OFF ON - Muting attenuation Att-1 ON b OFF b - ON OFF OFF ON - Att-2 ON b OFF b - ON OFF OFF ON - Att-3 ON b OFF b - ON OFF OFF ON - Separation Separation ON b OFF b - ON OFF OFF ON - Stereo on level ST-ON ON b OFF b - ON OFF OFF ON - Stereo off level ST-OFF ON b OFF b - ON OFF OFF ON - Main total harmonic distortion THD-Main L ON b OFF b - ON OFF OFF ON - Pilot cancellation PCAN ON b OFF b - ON OFF OFF OFF/ON - SNC output attenuation AttSNC ON b OFF b - ON OFF OFF ON - HCC output attenuation 1 AttHCC-1 ON b OFF b - ON OFF OFF ON - HCC output attenuation 2 AttHCC-2 ON b OFF b - ON OFF OFF ON - Input limiting voltage VIN-LIM ON b OFF b - ON OFF OFF ON ON Muting sensitivity VIN-MUTE ON b OFF b - ON OFF OFF ON - SD sensitivity 1 SD-sen1 FM ON b OFF b OFF OFF OFF OFF ON - SD sensitivity 2 SD-sen2 FM ON b OFF b ON OFF OFF OFF ON - IF counter buffer output VIFBUFF-FM ON b OFF b OFF OFF OFF OFF ON - Signal meter output (FM) VSM FM-1 ON b OFF b - ON OFF OFF ON - VSM FM-2 ON b OFF b - ON OFF OFF ON - VSM FM-3 ON b OFF b - ON OFF OFF ON - VSM FM-4 ON b OFF b - ON OFF OFF ON - Muting bandwidth BW-MUTE ON b OFF b - ON OFF OFF ON - Mute drive output VMUTE-100 ON b OFF b - ON OFF OFF ON - N-AGC on input VNAGC ON a ON b - ON OFF OFF - - W-AGC on input VWAGC ON a ON b - ON OFF OFF - - Conversion gain A.V ON a ON b - ON OFF OFF - - Oscillator buffer output VOSCBUFF-FM ON a ON b - ON OFF OFF - - Gate time 1 τGATE1 ON - OFF a - ON OFF OFF - - Noise sensitivity SN ON - OFF a - ON OFF OFF - - NC effect SN-NC ON/OFF - OFF a - ON OFF OFF - - MRC output VMRC ON - OFF b - ON OFF OFF - - MRC operating level MRC-ON ON - OFF b - ON OFF OFF - - Practical sensitivity S/N-30 OFF - OFF b ON ON - - - - Detection output VO-AM OFF - OFF b ON ON - - - - Pin 31 detection output VO-AM31 OFF - OFF b ON ON - - - - AGC F.O.M. VAGC-FOM OFF - OFF b ON ON - - - - Signal-to-noise ratio S/N-AM OFF - OFF b ON ON - - - - Total harmonic distortion (AM) THD-AM OFF - OFF b ON ON - - - - Signal meter output (AM) VSM AM-1 OFF - OFF b ON ON - - - - VSM AM-2 OFF - OFF b ON ON - - - - Oscillator buffer output VOSCBUFF-AM1 OFF - OFF b ON ON - - - - Wide band AGC sensitivity W-AGCsen1 OFF - OFF b ON ON - - - - W-AGCsen2 OFF - OFF b ON ON - - - - SD-sen1 AM OFF - OFF b OFF OFF - - - - SD-sen2 AM OFF - OFF b OFF OFF - - - - VIFBUFF-AM OFF - OFF b OFF OFF - - - - SD sensitivity IF buffer output No.6038-20/48 LA1781M Usage Notes 1. Notes on VCC and Ground Pin 40 VCC for the FM IF, AM, NC, MPX, and MRC blocks Pin 25 Ground for the FM IF and AM blocks Pin 14 Ground for the NC, MPX, and MRC blocks Pin 61 VCC for the FM front end, AM first mixer, and first oscillator blocks *Pin 6 VCC for the FM front end and AGC blocks, and the AM/FM switching pin Pin 3 Ground for the FM front end, first mixer, and first oscillator blocks 2. Notes on AM Coil Connection The VCC used for the first oscillator coil connected to pin 7 must be at the same potential as pin 61. Connect to the IFT connected with pin 45, and to the MIX coil connected with pin 54. VCC must be at the same potential as pin 40. 3. AM/FM Switching Pin 6 is also used as the FM front end and RF AGC VCC V6pin Pin 6 voltage 8 Mode 8 FM OPEN AM 3.3 AM FM AM Fig. 1 4. Notes on the FM Front End Notes on interference rejection characteristics • Intermodulation characteristics The LA1781M applies two high-band AGC functions to prevent IM (the generation of intermodulation). These are the narrow AGC (pin 58 : mixer input detection type) and the wide AGC (for the pin 55 input), and this results in the antenna frequency characteristics shown in figure 2. The levels at which the AGC functions turn on are determined by the capacitors attached at pins 55 and 58. Δf -- AGC Sensitivity When Δf = 0, 98.1MHz AGC sensitivity -- dBμ 110 100 The wide AGC sensitivity when pin 39 is 5V. 90 80 70 The narrow AGC sensitivity when pin 39 is at ground. 60 50 --5 --4 --3 --2 --1 0 1 2 3 4 5 Δf -- MHz Fig. 2 No.6038-21/48 LA1781M • Notes on second-channel attenuation suppression Keyed AGC (3D AGC) is a technique for achieving good characteristics for both intermodulation and secondchannel attenuation at the same time. When the desired signal is faint or nonexistent, the high-band AGC level will be essentially 0, and as a result automatic tuning may malfunction and blocking oscillation may occur in the presence of strong interfering stations. Keyed AGC helps resolve these problems. This 3D AGC technique uses information that has the following three frequency characteristics and is a unique Sanyo-developed system for determining the high-band AGC level. RF and ANT circuit information : Mixer input AGC Mixer circuit information : Mixer output AGC CF selectivity information : S-meter output • 3D AGC Features Feature Merit Only the narrow AGC sensitivity (operation at Δf < 1.5MHz) is controlled • Effective in resolving second-channel attenuation problems. by the field strength of the desired station. The narrow AGC sensitivity is controlled by a voltage (V23) that is under 0.5V. • Allows effective resolution of second-channel attenuation problems without under 0.5 V. degrading three-signal characteristics. The wide AGC can operate even when V23 = 0 (when the desired station is not present). • Seek operations may stop incorrectly due to the occurrence of intermodulation. • It is possible to prevent the occurrence of intermodulation in the RF tuning circuit and antenna in the presence of strong interfering stations, and blocking oscillation due to AGC operation can be prevented. The narrow and wide AGC sensitivities can be set independently. • Settings can be optimized for the field conditions. (See figure 3 and 4.) The system has two AGC systems : narrow and wide AGC. • Since the narrow AGC operates for the desired station and adjacent (See figure 5.) stations, the wide AGC sensitivity can be lowered and AGC malfunction due to local oscillator signal can be prevented. Δf -- AGC on Level (ANT input) Fig. 3 Δf -- AGC on Level (ANT input) Fig. 4 100 90 Pin 58 capacitor : 10pF 80 70 keyed AGC 39 Pin 58 capacitor : 47pF 60 100 90 Pin 55 capacitor : 10pF 80 70 keyed AGC 39 5V 60 50 50 --5 --4 --3 --2 --1 0 1 2 3 4 5 --5 Δf -- MHz 80 el Wide AGC on lev Narrow 90 AGC o n level 100 --4 --3 --2 --1 0 1 2 3 4 5 Δf -- MHz W-AGC, N-AGC -- f 70 Pin 59 narrow AGC and pin 55 wide AGC input levels -- dBμ Pin 55 capacitor : 3pF 110 Wide AGC on level -- dBμ Narrow AGC on level -- dBμ 110 Fig. 5 ristics frequency characte frequen cy chara cteristic s 110 120 130 140 AGC input level frequency characteristics such that VRFAGC (pin 2) falls under 2V. 7 1.0 2 3 5 7 10 2 3 5 7 100 2 3 5 Frequency, f -- MHz No.6038-22/48 LA1781M 3D AGC Sensitivity Characteristics AGC sensitivity Wide AGC sensitivity ΔF 1 2 Second-channel attenuation improvement Narrow AGC sensitivity 3 Desired station AGC sensitivity 4 V23 (Desired station field strength) Fig. 6 The fu input level at which antenna damping turns on -- dBμ Figure 6 3D AGC Sensitivity - Δf, V23 characteristics • The wide AGC sensitivity is determined by the antenna and RF circuit selectivity, regardless of V23. • The narrow AGC sensitivity is determined by the following. The total selectivity of the antenna, RF circuit, and mixer when V23 ≥ 0.5V The above selectivity and V23 when V23 < 0.5V • The improvement in the second-channel attenuation corresponds to the area occupied by the narrow AGC in the total AGC sensitivity area. Figure 8 on the next page shows the actual operation of the circuit. Δf -- AGC on Level (ANT input) When Δf = 0, 98.1MHz 110 fD = 98.1MHz Second-dhannel pad 100 ANT IN VIN 90 80 70 fu = 98.1MHz + Δf 60 50 --5 --4 --3 --2 --1 0 1 2 3 4 5 Δf -- MHz Fig. 7 No.6038-23/48 LA1781M Notes on 3D AGC (Keyed AGC) VCC 55 W-AGC DET 58 N-AGC DET 90μA S-meter + -VCC + -- 1 2 39 24 + ANT DUMPING VS-meter Fig. 8 • The antenna damping current from the pin due to the pin diode flows when the V2 pin reaches the VCC - VBE level. • The narrow AGC operates as follows. When pin V39 > pin V24 : The narrow AGC turns off. When pin V39 < pin V24 : The narrow AGC turns on. No.6038-24/48 LA1781M • The LA1781M includes two AGC circuits in its front end block. (1) Antenna input limiter using a pin diode. (2) FET second gate control The AGC input pin is pin 59, and the AGC circuit turns on when a signal of about 30mVrms is input. AGC activation The pin diode drive circuit turns on when VCC - V2 is greater than or equal to about 1V, and input limitation is applied to the antenna circuit. In application circuits, there will be an attenuation of about 30 to 40dB. Next, when an adequate current flows in the antenna attenuator pin diode, the inductance falls, the FET second gate voltage drops, the FET gm falls, and the AGC operates. The recommended FET is the Sanyo 3SK263, which is an enhancement-type MOSFET. Therefore, full AGC is applied when the voltage, VG2-S, between the second gate and the source is 0. Note that if a depletion-type MOSFET is used, AGC will not be applied unless VG2-S is less than 0. 9 V2 AGC Characteristics Fig. 9 fr = 98.0Hz VCC = 8V Ta = 25°C 8 6 5 4 Range where AGC level AGC level due the AGC does due to the to the MOSFET not operate pin diode : second gate : about 35dB about 35dB 3 2 1 0 --10 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 ANT IN -- dBμ 63 62 MIX VCC 60 MIX INPUT Due to optimized device geometry, emitter current, the bias, this IC achieves the following performance. 59 MIX OUT 64 MIX OUT • Mixer The mixer circuit in this IC is a double-balanced mixer with both balanced input and balanced output. Input circuit type Emitter input Input impedance : 25Ω MIX IMPUT V2AGC -- V 7 MIX Mixer input usable sensitivity : 15dBμ Mixer input IMQS : 90.5dBμ (For an oscillator level of 200mVrms) OSC * The mixer input IMQS is defined as : fr = 98.8MHz, no input fu1 = 98.8MHz, 1kHz, 30% modulation fu2 = 99.6MHz, no modulation The interference 1 and 2 input levels such that generated intermodulation output signal-to-noise ratio becomes 30dB when an interference signal with the same level as the mixer input is input, and distortion occurs in the mixer. Mixer circuit Fig. 10 No.6038-25/48 LA1781M • Oscillator Figure 11 shows the type of oscillator circuit used in this IC. It includes both an oscillator and an oscillator buffer. VCC 18pF 4 25pF 5 VT AM/FM OSC BUFFER OUT 20pF Fig. 11 • Figure 12 shows the type of FM first IF amplifier used in this IC. It is a differential single-stage amplifier. 330Ω FM IF input TO MIX 56 53 330Ω + 330Ω -- Fig. 12 Specifications Input impedance : 330Ω Output impedance : 330Ω Gain : 20dB No.6038-26/48 LA1781M 5. FM IF • Notes on the FM SD and SD adjustment The figure below presents an overview of the FM SD and the IF count buffer. R 4.9V + -- R + -- R Band muting Muting drive output HOLE CLET STEREO IND S-meter IF count buffer + -- 39 FM IF 24 33 23 26 5V IF count output SD STEREO/MONO 2.5V 5V Fig. 13 Figure 14 shows the relationship between the FM SD, the IF count buffer output, the S-meter, and the muting drive output. V24 Larger values of R33 S-meter V38 V33 Smaller values of R33 V33 over 0.7V V33 over 0.7V V26 5V SD ON On as an SD signal SD ON Mono Stereo V23AC 0.7V OFF IF count buffer OFF IF counter output off V23DC 5V 2.5V 0V RDS and other types of SD detection can be used by switching these modes. New LA1784M functionality : For stereo input (when the V26 pin voltage is 0.7V), when this pin is shorted to ground (0.1V or lower) the IC will operate in forced mono mode. Fig. 14 No.6038-27/48 LA1781M • Transient response characteristics during automatic tuning The transient characteristics for SD and IF count buffer on/off operation are determined by the time constants of the RC circuits attached to the following pins. (1) Muting time constant : pin 33 (2) S-meter time constant : pin 24 (3) AFC time constant : pin 34 There are two points that require consideration when using fast tuning. (1) The SD time constant due to the S-meter time constant Since the current I24 (pin 24) varies with the field strength, the time constant also changes. There is no hysteresis in the comparator. If C24 is made smaller and the pin 24 voltage is used for the keyed AGC pin 23, C23 must be chosen so that AGC during keyed AGC operation does not become unstable. S-meter SD comparator I24 24 R24 C24 Fig. 15 (2) The SD time constant due to the pin 33 muting voltage time constant The changes in volume due to field fluctuation during weak field reception can be made smoother by setting the attack and release times during soft muting operation. Mute drive Mute amp 10kΩ 50kΩ Attack Muting time constants Attack : 10kΩ × C33 Release : 50kΩ × C33 Release 33 C33 Antenna input such that pin 5 goes high -- dBμ Fig. 16 SD Sensitivity Adjustment 50 Fig. 17 40 30 20 10 0 6 10 14 18 22 26 30 34 Resistance between the pin and ground -- kΩ No.6038-28/48 LA1781M However, when testing this stop sensitivity, note that when checking the waveform on the IF count buffer output (pin 23), there are cases, such as that shown below, where current in the test system may be seen as flowing to ground and cause oscillation that causes the IF count buffer output to go to the output state. F.E. IF IF BUFFER AMP 5V 0.022μF Test system capacitance The 10.7MHz feeds back through ground. Fig. 18 • FM Muting control pin (pin 47) (R47 : 30kΩ variable resistor) The -3dB limiting sensitivity can be adjusted with R47. FM Soft Muting (1) 10 R47 = 7.5kΩ 0 Fig. 19 DET out 15kΩ Output, noise -- dB --10 10kΩ --20 --30 20kΩ --40 --50 Nois e --60 --70 --20 --10 0 10 20 30 40 Antenna input -- dBμ • FM muting attenuation adjustment (pin 58) The muting attenuation can be switched between the three levels of -20, -30, and -40dB by the resistor inserted between pin 58 and ground. (Note that the exact values depend on the total tuner gain.) The noise convergence with no input is determined by the pin 58 voltage. 58 100Ω R58 33 R58 Mute ATT Open -20dB 200kΩ -30dB 30kΩ -40dB The attenuation can be set by making R33 smaller as listed in the table above. R33 Fig. 20 No.6038-29/48 LA1781M FM Soft Muting (2) 10 Fig. 21 FM Soft Muting (3) 10 R47 = 7.5kΩ DET out 0 R47 = 7.5kΩ 0 Fig. 22 DET out 10kΩ 10kΩ --10 --10 Output -- dB Output, noise -- dB Output -- dB 15kΩ --20 58 200kΩ --30 --40 20kΩ --50 --20 15kΩ 58 30kΩ --30 --40 --50 Noi se --60 --60 --70 --20 --10 0 10 20 30 --70 --20 40 Antenna input -- dBμ Noi se 20kΩ --10 0 10 20 30 40 Antenna input -- dBμ VCC Quadrature detector 200kΩ R Mute amp. (VCA) + -- R + -- N-AGC Mute drive Limiter R 58 33 31 DET out To MIX out Open 200kΩ 30kΩ Fig. 23 • FM muting off function Forcing this pin to the ground level turns muting off. Detecter output 0 1 When the pin is at the ground level, the noise convergence will be 10dB and the -3dB limiting sensitivity will be about 0dBμ. 20 Antenna input Fig. 24 No.6038-30/48 LA1781M • Hall detection The Hall detection function detects the level of the pin 36 quadrature input signal and then applies peak detection to that result. The result is output from pin 33. This circuit has three effects. (1) It assures that muting will be applied for weak inputs with an antenna input of under 5dBμ. The amount of attenuation is referenced to an antenna input of 60dBμ, fm = 1kHz, and a 22.5kHz dev output, and is variable from 10dB to 40dB when there is no input. Thus one feature of this circuit is that the weak input noise attenuation and the -3dB limiting sensitivity for over 5dBμ inputs can be set independently. 5 Hall Detection Output -- Antenna Input Characteristics Fig. 25 Area muted by Hall detection V38pin -- V 4 3 2 1 0 --20 --10 0 10 20 30 Antenna input -- dBμ (2) When the pin 36 quadrature input is a saturated input, the pin 36 noise level (Va) is detected and a peak-hold function is applied to pin 33 (Vb) for locations rapid field strength variations and severe multipath occurs for fields that result in an antenna input level of over 5dBμ. 36 33 Vb Va 0 + 0.1μF 0 Fig. 26 (3) Unique features One unique feature of the LA1781M is that if there are adjacent stations such that f1 = 98.1MHz and f2 = 97.9MHz, a search operation will not stop at 98.0MHz. Since VAFC = 0V and VSM = 3.6V at 98.0MHz in the situations shown in figure 27 and 28, even though Hall detection would normally not operate and SD would be high, in this IC the Hall detection circuit will operate, VMute will be set to 1.2V (over 0.7V) and the SD signal will go low, thus preventing incorrect stopping of the search. No.6038-31/48 Unique Featuers of the LA1781M Hall Detection circuit (1) Fig. 27 2 1 When the tuner is moved in 50kHz steps. With a 51kΩ resistor between pins 37 and 34. With the SD sensitivity adjusted to be 20dBμ. f1 ANT IN f2 0 6 4 2 0 6 4 2 f2 = 97.9MHz, 120dBμ fm = 400Hz, 22.5kHz dev. f1 = 98.1MHz, 120dBμ fm = 1kHz, 22.5kHz dev. 0 1 When the tuner is moved in 50kHz steps. With a 51kΩ resistor between pins 37 and 34. With the SD sensitivity adjusted to be 20dBμ. 0 6 4 2 97.8 97.9 98.0 98.1 98.2 6 4 2 0 6 4 2 f2 = 97.9MHz, 40dBμ fm = 400Hz, 22.5kHz dev. f1 = 98.1MHz, 40dBμ fm = 1kHz, 22.5kHz dev. 0 8 Pin 26 (SD) -- V Pin 26 (SD) -- V 8 0 97.7 Unique Featuers of the LA1781M Hall Detection circuit (2) Fig. 28 2 --1 Pin 24, VSM -- V Pin 24, VSM -- V --1 Voltage between pins 37 and 34, VAFC -- V Pin 33, VMute -- V Voltage between pins 37 and 34, VAFC -- V Pin 33, VMute -- V LA1781M 6 4 2 0 97.7 98.3 Frequency, fr -- MHz 97.8 97.9 98.0 98.1 98.2 98.3 Frequency, fr -- MHz • Notes on the quadrature input level When a strong field is being received the quadrature signal input (pin 36) requires a 200mVrms input, and the detection transformer and the damping resistor between pins 36 and 37 must be designed. (We recommend the Sumida SA-208 transformer and a 10kΩ resistor between pins 36 and 37.) When the pin 36 input level falls below 160mVrms, the Hall detection circuit operates and the pin 33 mute drive output voltage increases. Therefore, when pin 36 input is from 160 to under 200mV rms during strong field reception, the muting circuit may or may not operate due to sample-to-sample variations between individual ICs. Furthermore, the SD function may not operate, and the audio output level may be reduced. Incorrect operation due to sample-to-sample variations and temperature characteristics can be prevented by keeping the pin 36 voltage at 200mVrms or higher. 6 Pin 33 VMute -- QD Input Level SA208 + LA1781M IF Input Characteristics Fig. 29 Fig. 30 4 0.8 With pins 34 and 37 shorted. With 5V applied to pin 24. 3 0.6 5 2 0.4 THD -- % Vmute -- V 4 3 2 75Ω SG 75Ω + 0.022μF 36 10.7MHz 0 92 94 96 37 98 --100 --80 --60 --40 --20 --120 With the resistorbetween pins 36 and 37 open. With a 10kΩ resistor between pins 36 and 37 1 0 20 --0.2 --0.4 --0.6 LA1888M 100 102 THD 1kHz 75kHz dev 1 0.2 40 60 80 Δf -- kHz 100 120 Δf = 0 → 10.7kHz Voltage between pins 37 and 34 --0.8 (referenced to the pin 37 voltage) 104 106 QD input level -- dBμ No.6038-32/48 LA1781M Detector output Pin 36 AC level MPX OUT R36-37 VO QDIN Open 330mVrms 235mVrms 10kΩ 280mVrms 200mVrms Bandwidth such that the pin 33 voltage ≥ 2V -- kHz • Band Muting Adjustment Procedure The muting bandwidth can be modified as shown in figure 31 with the resistor RBW between pin 34 and 37. RBW -- Muting Bandwidth Fig. 31 280 RBW + 240 + 1μF 0.47μF 200 SA208 Sumida 10kΩ 37 160 36 35 34 ANT IN 98MHz 100dBμ 120 80 40 0 1.0 2 3 5 7 2 10 3 5 7 100 2 Resistor RBW between pins 34 and 37 -- kΩ 6. AM • AM AGC system The LA1781M RF AGC circuit takes its input from three sources : the WIDE AGC pin (pin 46), the MIDDLE AGC pin (pin 49) and NARROW AGC. There is also an IF AGC circuit. RW 1st MIX 10.7MHz CF 62 RF 2nd MIX 450kHz CF 49 IF Amp. DET 52 31 VCC 42 1st OSC X'tal 240kΩ VCC Amp. 46 IF AGC 44 2.2μF Middle AGC IN Narrow AGC IN Wide AGC IN ANT DUMPING RF AGC 57 + 47μF 48 + 3.3μF Fig. 32 No.6038-33/48 LA1781M AM AGC f characteristics Wide AGC Operates for wide band interference AGC on level 90 Middle AGC Operates for interference within ±70kHz of the received frequency. 80 70 800 Middle AGC Operates for interference within ±70kHz of the received frequency. Narrow AGC Operates at the received frequency. 60 1000 900 Fig. 33 100 Wide AGC Operates for wide band interference 1100 1200 Frequency -- Hz Wide Band AGC Circuit 30Ω Fig. 34 Received frequency : 1MHz 0.022μF 46 110 50Ω --6dB SG 50Ω 0.022μF 100 510Ω ANTD 0.022μF 90 80 70 1.0 2 3 5 7 2 10 3 5 Pin 46 input -- MHz The wide band AGC circuit in this IC has the frequency characteristics shown above. The pin 46 input frequency characteristics are identical to those of the RF amplifier gate. This AGC circuit serves to prevent distortion at the FET input when a strong signal is applied to the antenna circuit. The level at which the AGC circuit turns on can be adjusted to an arbitrary level with the wide band AGC adjustment resistor. A delayed AGC on level can be handled by reducing the value of the adjustment resistor. Wide band AGC adjustment resistor 30Ω 0.022μF VCC 620Ω 1MH 100μH FC18 57 15pF + 15pF 47μF 100kΩ 0.022μF 100μH 30MH Anternna damping on input level -- dBμ 120 62 Fig. 35 No.6038-34/48 LA1781M • Notes on AM SD (pin 26) and the SD adjustment pin SD and the IF buffer are operated by comparing the S-meter level (V24) and the 5V reference voltage as shown in figure 36. S-meter AM IF Comparator VCC + -- IF buff amp. 50pF 50μA 55 24 23 26 100kΩ 100kΩ 0.47μF 0.022μF 51kΩ IF buffer 5V SD Seek 5V Fig.36 Figure 37 shows the relationship between the AM SD, the IF count buffer, and the S-meter. V24PIN Larger values of R55 S-meter V55 V26 Smaller values of R55 SD on V23AC IF buffer on OFF V23DC 5V Pin 55 AM SD adjustment pin 0V Antenna input such that pin 26 becomes 5V -- dBμ Fig.37 AM SD Sensitivity Adjustment 80 Fig. 38 70 60 50 40 30 20 10 0 0 10 20 30 40 50 Resistance between pin 55 and ground -- kΩ No.6038-35/48 LA1781M • AM high band cut and detector output level adjustment methods The pin 31 AM and FM tuner output has an impedance of 10kΩ in AM mode and a few tens of Ohms in FM mode. Therefore, R31 is used to lower the AM detector output level and C31 determines the AM high band frequency characteristics. VCC FM detector 31 R31 C31 VCC + AM detector 10kΩ 30 Noise canceler input 50kΩ Fig. 39 • AM stereo system pins To the AM stereo decoder VCC GND 400mVrms 450kHz output IFT 45 39 VCC 50pF 150Ω KEYED AGC IF AMP. Fig. 40 No.6038-36/48 LA1781M • AM low band cut adjustment method The AM low band frequency characteristics can be adjusted with C42, which is inserted between pin 42 and VCC. Since the detector is designed with VCC as the reference, C42 must be connected to VCC. Detector Output -- Frequency 20 80%mod 0.1μF VCC 10 With no C31 used. 50kΩ 10kΩ + AM detecter 10kΩ -- 50kΩ To pin 31 10kΩ Detector output -- dB C42 42 Fig. 42 0 30%mod 0.022μF --10 0.047μF C31pin = 6800pF 0.1μF --20 C42pin = Using SEP 450H --30 --40 fr = 100kHz fm = 10kHz 30%mod Fig. 41 --50 3 5 70.01 2 3 5 7 0.1 2 3 5 7 1.0 2 3 5 7 10 2 Frequency -- Hz 7. Noise Canceler Block • The noise canceler input (pin 30) has an input impedance of about 50kΩ. Check the low band frequency characteristics carefully when determining the value of the coupling capacitor used. Note that fC will be about 3Hz when a 1μF capacitor is used in the application. • Pins 8 and 9 are used to set the noise detector sensitivity and the noise AGC. It is advisable to first set the noise sensitivity for a medium field (an antenna input of about 50dBμ) with pin 8 (the noise sensitivity setting pin), and then set the AGC level for a weak field (20 to 30dBμ) with pin 9 (the AGC adjustment pin). If the noise sensitivity is increased, the AGC will become more effective but, inversely, the weak field sensitivity will be reduced. Noise canceler 10kHz overmodulation malfunction may be a problem. In particular, when an overmodulated signal is input, the noise canceler may, in rare cases, malfunction. This is due to the fact that the IF detector output has a waveform of the type shown in figure 43 due to the bands of the IF ceramic filters as shown below. (Here, the antenna input is 60dBμ, the ceramic filters are 150kHz × 1 and 180kHz × 2, f = 10kHz, 180kHz dev.) The noise canceler reacts to the spikes (whiskers) generated due to this overmodulation, which results in distortion to the audio output. (The spike components due to overmodulation occur due to the bands of the ceramic filters in the tuner.) The following describes a method for resolving this problem. This incorrect operation due to overmodulation is prevented by removing the spike components due to this overmodulation with a low-pass filter consisting of a 1kΩ resistor and a 2200pF capacitor shown in figure 44. However, note that the FM separation characteristics in the high band and the AM frequency characteristics will change. IF audio output f = 10kHz,180kHz dev IF output 1kΩ Noise canceler input + H1 W1 2.5OU 31 2200pF -- 30 1μF Fig.44 --2.5OU --19.00ms 981.00μs Fig. 43 No.6038-37/48 LA1781M 8. Multiplexer Block • HCC (high cut control) frequency characteristics (pin 41) When the HCC function operates, the frequency characteristics of the output signal are determined by the capacitance of the external capacitor connected to pin 41. 20kΩ To The Matrix VO (dB) 41 C Fig. 45 1 2πC × 20kΩ f (Hz) 1 [Hz] 2π × C × 20kΩ fC = Fig. 46 Frequency Characteristics 10 0 0.001μF 0μ F --10 0.0022μF --20 0.0047μF --30 1μ 0.0 --40 F Attenuation, HCC -- dB Fig. 47 Changes in the pin 41 capacitor capacitance (for a 100% high cut ratio) VCC = 8.0V f = 98MHz 100%mod 80dBμ IN --50 --60 3 5 7 100 2 3 5 7 1k 2 3 5 7 10k 2 3 Frequency, f -- Hz • Pilot canceler adjustment (pins 17 and 18) NCoise canceler input -- 30 To the multiplexer Gate Pilot cancel 11 12 17 6800pF 3.9kΩ 18 0.01μF 50kΩ Fig. 48 The pilot canceler signal waveform (pin 19) is a 19kHz signal that contains no third harmonic as shown in figure 48. Since this signal has the same phase as the pilot signal, no capacitor is required between pin 18 and ground. Since it has no third harmonic component, excellent pilot cancellation can be acquired in both the left and right channels by adjusting with a variable resistor. No.6038-38/48 LA1781M • Separation adjustment (pin 19) 5kΩ To The subdecoder Larger 19 20kΩ C 0.047μF Fig. 49 The separation is adjusted by modifying the input level to the subdecoder with the variable resistor connected to pin 19. Since only the sub-modulation level is changed by changing the variable resistor setting, the monaural (main) output level is not changed. Furthermore, degradation of high band separation in the decoder can be avoided if the impedance of the external capacitor (C) in the subchannel frequency band (23 to 53kHz) is made sufficiently smaller than the variable resistor. 9. MRC Circuit VCC 2μA S-meter 100Ω FM S-meter DC buffer MRC 30kΩ 6.4kΩ 10kΩ 3.6kΩ 24 + QMRC 75pF 1kΩ 32 Noise amplifiter High-pass filter with Fc = 70 kHz + amplifiter An external transistor equivalent to the 2SC536 is required Reason : A QMRC level shifter is required to allow a simplified MRC circuit to be used in the LA1781M. 27 + C27 VCC To the SNC, pin 28 Fig. 50 No.6038-39/48 LA1781M (1) When there is no AC noise on pin 32 V24 = V27 - VBE ↑ QMRC V27 is about 2.5V when the antenna input is 60dB or higher. (2) Since the MRC noise amplifier gain is fixed, the MRC circuit is adjusted by reducing the AC input level. 32 + Fig. 51 (3) The MRC attack and release are determined by C27 on pin 27. Attack : 7μA × C27 → 2μA × C27 Release : 500Ω × C27 → 100Ω Notes on the Noise Canceler The noise canceler characteristics have been improved by implementing the circuit that determines the gate time in logic. Since the time constant in earlier noise cancelers was determined by an RC circuit such as that shown in figure 52, the rise time shown in figure 53 was influenced by the values of the resistor and capacitor used. As a result the noise exclusion efficiency was reduced by this delay in the rise time. In the LA1781M, this rise time was shortened by implementing the circuit that determines the gate time in logic, allowing it to reliably exclude noise. Fig. 52 Fig. 53 No.6038-40/48 LA1781M Gain Distribution (FM) This section investigates the gain in each block in the LA1781M when the Sanyo recommended circuits are used. (Test conditions) Ambient temperature : 26°C Antenna and mixer input frequency : 98.1MHz First and second IF input frequency : 10.7MHz The input levels when VSM = 2V will be as follows. ANT IN : 19dBμ MIX IN : 30dBμ 1st IF IN : 42dBμ 2nd IF IN : 60dBμ When the gains for each block are determined according to the above, the results are as follows. RF GAIN : 11dB MIX GAIN : 12dB 1st IF GAIN : 18dB 1st IF IN 56 pin FM MIX IN 64 pin RF ANT IN 2nd IF IN 51 pin 11dB 12dB 18dB Fig. 54 (AM) This section investigates the gain in each block in the LA1781M when the Sanyo recommended circuits are used. (Test conditions) Ambient temperature : 26°C Antenna and mixer input frequency : 1MHz First and second mixer input frequency : 10.7MHz Second IF input frequency : 450kHz The gains at each stage will be as follows. RF Gain (ANT IN-pin62) : 17dB 1st MIX Gain (pin62-pin56) : 8dB 1st IF Gain (pin55-pin53) : 15dB AM 1st MIX 1st IF 2nd MIX 1st MIX Gain 1st IF Gain 2nd MIX Gain 2nd IF AM DET RF RF Gain 2nd IF Gain Fig. 55 No.6038-41/48 LA1781M Input Circuits for Each Stage [FM] • Mixer input • First IF input 75Ω 0.022μF 75Ω 63 300Ω 0.022μF 56 75Ω 64 75Ω VIN fr = 10.7MHz Actual measurement • IF input 75Ω 300Ω 0.022μF 51 75Ω 330Ω 50 0.022μF fr = 10.7MHz [AM] • First mixer input 50Ω • Second mixer input 0.022μF 50Ω 0.022μF 62 49 50Ω 50Ω fr = RF fr = 10.71MHz (f2nd osc + 0.45MHz) • IF input • Del input IFT 50Ω 0.022μF 50Ω 0.022μF 52 45 50Ω fr = 450kHz 50Ω fr = 450kHz No.6038-42/48 LA1781M Sample AM tuner Circuit with the LC72144 Used Together 2nd MIX CF RF CF IF CF 450K 1st IF 300Ω XBUFF LC72144 1st MIX 10.71MHz RF fosc AM 1st IF Step FM IF 1 fOSC 10.25NHz 10.7MHz 10kHz, 11kHz 10.7MHz 2 fOSC 10.35NHz 10.8MHz 9kHz, 10kHz 10.8MHz IF CF CF 10kΩ CF AF 62 59 60 56 53 49 54 1st OSC 52 2nd OSC 31 10.26MHz 10.7MHz RF 63 64 60 59 NC MPX Lch Rch IF CF CF 56 53 QUADRATURE DETECTOR AF 51 No.6038-43/48 LA1781M Crystal Oscillator Element Kinseki, Ltd. Frequency : 10.26MHz CL : 20pF Model No. : HC-49/U-S Coil Specifications Sumida Electronics, Ltd. [AM Block] AM FILTEER (SA-1051) 1 2 AM OSC (SA-359) S 3 3 4 2 6 4 1 AM IF1 (SA-264) 3 AM IF2 (SA-1063) 3 4 S 2 1 6 1 S S AM loading (SA-1062) 6 AM ANT IN (SA-1048) 4 3 4 2 2 1 4 2 S 3 6 1 6 6 S S AM RF amplifier (RC875-222J) 0.1φ2UEW [FM Block] FM RF (SA-1060) FM ANT (SA-1061) S 3 4 2 1 4 3 2 6 1 6 S FM OSC (SA-1052) 3 4 S FM MIX (SA-266) S 3 C1 4 8 2 2 1 6 S FM DET (SA-208) S S 3 4 1 7 C2 6 S 2 1 6 No.6038-44/48 LA1781M The Toko Electric Corporation [AM Block] AM FILTEER (A286LBIS-15327) 1 2 AM OSC (V666SNS-213BY) 3 3 4 2 6 1 4 AM IF1 (7PSGTC-5001A = S) 3 6 0.05φ3UEW AM loading (269ANS-0720Z) 3 1 6 0.05φ3UEW AM ANT IN (385BNS-027Z) 3 4 4 2 2 1 4 2 2 1 AM IF2 (7PSGTC-5002Y = S) 3 4 6 0.1φ2UEW 6 0.05φ3UEW 1 6 0.06φ3UEW AM RF amplifier (187LY-222) 0.1φ2UEW [FM Block] FM RF (V666SNS-208AQ) S 3 2 1 4 φ0.1--2UEW 6 S FM OSC (V666SNS-205APZ) 3 2 1 4 φ0.12--2UEW 6 S FM ANT (V666SNS-209BS) 3 4 2 1 φ0.1--2UEW 6 S FM MIX (371DH-1108FYH) S 3 4 2 5 1 6 S φ0.07--2UEW FM DET (DM6000DEAS-8407GLF) 3 4 2 1 6 0.07φ2MUEW No.6038-45/48 LA1781M FM I/O Characteristics R ch --10 --20 --30 --40 L ch --50 AM OUT NOISE --60 --70 --20 0 20 40 60 80 100 120 9 RF AGC 8 7 6 VSM 5 4 3 VMUTE VHCC 2 1 0 --20 140 VSNC 0 20 Antenna input -- dBμ 0 100 120 140 FM Sensitivity Suppression fu1 20 fu1 00 --10 7 6 5 4 3 OUT --20 --30 --40 --50 2 fm = 1kHz 100% 1 0 20 40 60 80 NOISE --60 fm = 1kHz 30% 100 --70 --20 140 120 0 20 FM Gain Distribution (1) 10 80 100 120 140 120 140 FM Gain Distribution (2) 8 1st IF ANT IN 60 7 IF 0 40 Antenna input -- dBμ Antenna input -- dBμ --40 F +I 60 IF 40 CF 1s --30 5 T DCV -- V MUTE OFF SNC, HCC OFF --20 t IF 6 33 AN --10 1kΩ 4 3 AM OUT 2 --50 1 --60 --70 --20 NOISE 0 20 40 60 80 100 0 --20 140 120 0 20 Input -- dBμ Mixer I/O Characteristics 110 First IF output -- dBμ 110 100 90 80 330Ω 70 60 50 60 70 80 90 Mixer input -- dBμ 100 90 80 0.022μF 75Ω 300Ω 56 V.V. 59 60 40 100 First IF I/O Characteristics 120 Input from pin 64 only 100 110 75Ω 120 80 Input -- dBμ 70 120 60 40 50 60 70 53 V.V. 0.022μF 330Ω Output, noise, AM output -- dB 80 fm = 1kHz 22.5k dev 8 Output, noise -- dB Total harmonic distortion, THD -- % 10 9 0 --20 Mixer output -- dBμ 60 Antenna input -- dBμ FM Distortion 10 40 fu90 OUT30% mod 0 FM I/O Characteristics 10 HCC, SNC, RF AGC, muting voltage, S-meter voltage, VSM -- V Output, noise, AM output, LR output -- dB 10 VIN 80 90 100 110 120 First IF input -- dBμ No.6038-46/48 LA1781M First IF Frequency Characteristics 10 400 FM Antenna Input Temperature Characteristics (1) 0 75kHz (100%mod) First IF output -- dB --10 --20 0.022μF 75Ω 300Ω 53 --40 V.V. 330Ω 56 0.022μF --30 75Ω First IF output -- dB 300 0.022μF VIN 7 1.0 2 3 5 7 10 2 3 5 22.5kHz (30%mod) 100 80dBμ IN --50 200 7 100 2 0 --40 3 --20 0 20 Frequency -- MHz FM Antenna Input Temperature Characteristics (2) 30 MUTE 80 EL N LEV AGC O S/N 70 60 50 60 80 100 FM Antenna Input Temperature Characteristics (3) 90 Antenna input -- dBμ S/N, AM output -- dB AGC on, separation, input level -- dBμ 100 40 Frequency -- MHz AM OUT 40 ATT 20 -3dB 10 S/N = LS 30dB 0 Separation 30 20 --40 --20 0 20 40 60 80 --10 --40 100 --20 50 0 20 40 60 80 100 Ambient temperature, Ta -- °C Ambient temperature, Ta -- °C FM Antenna Input Temperature Characteristics (4) 20 0 AM I/O Characteristics VCC = 8.5V f = 1MHz mod = 1k 30% OUT Output, noise -- dB 80dB IN 30 20 --40 NOISE --60 40dB IN 10 --80 20dB IN --20 0 20 40 60 80 --100 --20 100 0 20 Ambient temperature, Ta -- °C AM DC Characteristics 5.0 4.0 IF AGC 2.0 M VS 1.0 0 --20 0 20 40 60 80 ANT input, IN -- dBμ 100 80 100 120 140 120 140 VCC = 8.5V f = 1MHz mod = 1k 30% 80% 6.0 5.0 Hz 80% AGC, S-meter voltage -- V 6.0 3.0 60 AM Distortion 7.0 4.0 3.0 fm = 1k VCC = 8.5V f = 1MHz RF AGC Total harmonic distortion, THD -- % 7.0 40 ANT input, IN -- dBμ 2.0 z 30% 0 --40 --20 fm = 1kH Separation, Sep -- dB 40 1.0 0 --20 0 20 40 60 80 100 120 140 ANT input, IN -- dBμ No.6038-47/48 LA1781M AM Second-Channel Interference Rejection Characteristics 20 20 Δ40kHz AM Second-Channel Interference Rejection Characteristics Δ400kHz 100dBμ 100dBμ 0 --20 40dBμ desire mod OFF --40 60dBμ 100dBμ 50/3Ω --60 50Ω fD = 1MHz fm = 1kHz 30% --80 40 60 100 ANT input, IN -- dBμ Bμ 40dBμ --40 desire mod OFF 140 80dBμ 60dBμ 50/3Ω --60 120 60dBμ --20 15pF ANT IN 50/3Ω 30Ω 50Ω 50/3Ω VIN 65pF fu = 1040kHz fm = 400Hz 30% JIS ANT. DUMMY 80 40d dB μ 10 0d Bμ 80dBμ desire mod ON 80 40dBμ 60dBμ Output, noise -- dB desire mod ON 80 dB μ Output, noise -- dB 0 --80 40 50Ω fD = 1MHz fm = 1kHz 30% 60 15pF ANT IN 50/3Ω 30Ω 50Ω 50/3Ω VIN 65pF fu = 1400kHz fm = 400Hz 30% JIS ANT. DUMMY 80 100 120 140 ANT input, IN -- dBμ SANYO Semiconductor Co.,Ltd. assumes no responsibility for equipment failures that result from using products at values that exceed, even momentarily, rated values (such as maximum ratings, operating condition ranges, or other parameters) listed in products specifications of any and all SANYO Semiconductor Co.,Ltd. products described or contained herein. SANYO Semiconductor Co.,Ltd. strives to supply high-quality high-reliability products, however, any and all semiconductor products fail or malfunction with some probability. It is possible that these probabilistic failures or malfunction could give rise to accidents or events that could endanger human lives, trouble that could give rise to smoke or fire, or accidents that could cause damage to other property. When designing equipment, adopt safety measures so that these kinds of accidents or events cannot occur. Such measures include but are not limited to protective circuits and error prevention circuits for safe design, redundant design, and structural design. In the event that any or all SANYO Semiconductor Co.,Ltd. products described or contained herein are controlled under any of applicable local export control laws and regulations, such products may require the export license from the authorities concerned in accordance with the above law. No part of this publication may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying and recording, or any information storage or retrieval system, or otherwise, without the prior written consent of SANYO Semiconductor Co.,Ltd. Any and all information described or contained herein are subject to change without notice due to product/technology improvement, etc. When designing equipment, refer to the "Delivery Specification" for the SANYO Semiconductor Co.,Ltd. product that you intend to use. Information (including circuit diagrams and circuit parameters) herein is for example only; it is not guaranteed for volume production. Upon using the technical information or products described herein, neither warranty nor license shall be granted with regard to intellectual property rights or any other rights of SANYO Semiconductor Co.,Ltd. or any third party. SANYO Semiconductor Co.,Ltd. shall not be liable for any claim or suits with regard to a third party's intellctual property rights which has resulted from the use of the technical information and products mentioned above. This catalog provides information as of July, 2009. Specifications and information herein are subject to change without notice. PS No.6038-48/48