Ordering number : ENN5724A Monolithic Linear IC LA1780M Single-Chip Tuner IC for Car Radios Overview The LA1780M integrates all six blocks required in a car radio tuner on a single chip. The LA1780M is based on the LA1888NM, and features improvements to each of the blocks; improvements designed to provide improved noise characteristics, especially for noise related to multipath, three-signal intermodulation distortion, and two-signal suppression. Functions • FM front end • FM IF • Noise canceller • Multiplex • AM up-conversion • FM/AM switch • MRC 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.) • Since the LA1780M retains the block structure of the LA1888NM, products using that IC can be easily converted, allowing further end product miniaturization. Package Dimensions Unit:mm 3159-QFP64E Mounted on a 40 × 80 × 1.3 mm3 glass epoxy printed circuit board 17.2 14.0 0.35 1.6 1.0 0.15 33 1.6 1.0 Independent IC 0.8 1.0 48 32 0.8 17.2 14.0 49 64 1 Ambient temperature, Ta — °C 16 15.6 3.0max 17 1.0 Allowable power dissipation, Pdmax — mW [LA1780M] 0.1 2.7 0.8 SANYO: QFP64E (QIP64E) Any and all SANYO products described or contained herein do not have specifications that can handle applications that require extremely high levels of reliability, such as life-support systems, aircraft’s control systems, or other applications whose failure can be reasonably expected to result in serious physical and/or material damage. Consult with your SANYO representative nearest you before using any SANYO products described or contained herein in such applications. SANYO 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 products described or contained herein. SANYO Electric Co.,Ltd. Semiconductor Company TOKYO OFFICE Tokyo Bldg., 1-10, 1 Chome, Ueno, Taito-ku, TOKYO, 110-8534 JAPAN 33100TN (OT)/92498RM (OT) No. 5724-1/38 LA1780M Specifications Maximum Ratings at Ta = 25°C Parameter Symbol Maximum supply voltage Allowable power dissipation Conditions VCC1 max Pins 6, 40, and 61 VCC2 max Pins 7, 45, 54, 59, and 60 Pd max Ratings Unit 9 Ta ≤ 55°C V 12 V 950 mW Operating temperature Topr –40 to +85 °C Storage temperature Tstg –40 to +150 °C Operating Conditions at Ta = 25°C Parameter Symbol VCC Recommended supply voltage VCCST IND Conditions Ratings 8 V Pin 26 5 V 7.5 to 9.0 V VCC op Operating supply voltage range Unit Pins 6, 7, 40, 45, 54, 59, 60, and 61 Operating Characteristics at Ta = 25°C, VCC= 8.0V, in the specified test cricuit for the FM IF input Ratings Parameter Symbol Conditions min typ max unit [FM Characteristics] At the FM IF input Current drain Demodulation output Pin 31 demodulation output Channel balance Total harmonic distortion ICCO-FM No input, I40 + I45 + I54 + I59 + I60 + I61 60 94 110 mA VO-FM 10.7 MHz, 100dBµ, 1 kHz, 100%mod, The pin 15 output 205 310 415 mVrms VO-FM31 10.7 MHz, 100dBµ, 1 kHz, 100%mod, The pin 31 output 190 295 380 mVrms The ratio between pins 15 and 16 at 10.7 MHz, 100 dBµ, 1 kHz –1 0 +1 dB 0.3 1 CB THD-FM mono 10.7 MHz, 100 dBµ, 1 kHz, 100% mod, pin 15 Signal-to-noise ratio: IF S/N-FM IF 10.7 MHz, 100 dBµ, 1 kHz, 100% mod, pin 15 75 82 dB AM suppression ratio: IF AMR IF dB Muting attenuation Separation 10.7 MHz, 100 dBµ, 1 kHz, fm = 1 kHz, 30% AM, pin 15 55 68 Att-1 10.7 MHz, 100 dBµ, 1 kHz. The pin 15 attenuation when V33 goes from 0 to 2 V 5 10 15 dB Att-2 10.7 MHz, 100 dBµ, 1 kHz. The pin 15 attenuation when V33 goes from 0 to 2 V*1 15 20 25 dB Att-3 10.7 MHz, 100 dBµ, 1 kHz. The pin 15 attenuation when V33 goes from 0 to 2 V*2 28 33 38 dB 10.7 MHz, 100 dBµ, L+R = 90%, pilot = 10%. The pin 15 output ratio 30 40 Separation Stereo on level ST-ON The pilot modulation such that V26 < 0.5 V 1.2 2.4 Stereo off level ST-OFF The pilot modulation such that V26 > 3.5 V 0.6 1.6 Main total harmonic distortion THD-Main L 10.7 MHz, 100 dBµ, L+R = 90%, pilot = 10%. The pin 15 signal Pilot cancellation PCAN 10.7 MHz, 100 dBµ, pilot = 10%. The pin 15 signal/the pilot level leakage. DIN audio SNC output attenuation AttSNC 10.7 MHz, 100 dBµ, L-R = 90%, pilot = 10%. V28 = 3 V → 0.6 V, pin 15 Muting sensitivity dB 4.4 % % 0.3 1.2 % 20 30 dB 1 5 9 dB 0.5 4.5 8.5 dB AttHCC-1 10.7 MHz, 100 dBµ, 10 kHz, L+R = 90%, pilot = 10%. V29 = 3 V → 0.6 V, pin 15 AttHCC-2 10.7 MHz, 100 dBµ, 10 kHz, L+R = 90%, pilot = 10%. V29 = 3 V → 0.1 V, pin 15 6 10 14 dB 100 dBµ, 10.7 MHz, 30% modulation. The IF input such that the input reference output goes down by 3 dB 33 40 47 dBµ HCC output attenuation Input limiting voltage % Vi-lim The IF input level (unmodulated) when V33 = 2 V 27 35 43 dBµ The IF input level (unmodulated) (over 100 mV rms) such that the IF counter buffer output goes on 54 62 70 dBµ 54 62 70 dBµ VIFBUFF-FM 10.7 MHz, 100 dBµ, unmodulated. The pin 23 output 220 330 440 mVrms VSM FM-1 No input. The pin 24 DC output, unmodulated 0.0 0.1 0.3 V VSM FM-2 50 dBµ. The pin 24 DC output, unmodulated 0.4 1.0 1.5 V VSM FM-3 70 dBµ. The pin 24 DC output, unmodulated 2.0 2.7 3.5 V VSM FM-4 100 dBµ. The pin 24 DC output, unmodulated 4.7 5.5 6.2 V Muting bandwidth BW-mute 100 dBµ. The bandwidth when V33 = 2 V, unmodulated 100 150 200 kHz Mute drive output VMUTE-100 100 dBµ, 0 dBµ. The pin 33 DC output, unmodulated 0.00 0.03 0.20 V SD sensitivity Vi-mute SD-sen1 FM SD-sen2 FM IF counter buffer output Signal meter output Continued on next page. No. 5724-2/38 LA1780M Continued from preceding page. Ratings Parameter Symbol Conditions min typ max unit [FM FE Mixer Input N-AGC on input VN-AGC 83 MHz, unmodulated. The input such that the pin 2 voltage is 2.0 V or below 80 87 94 dBµ W-AGC on input VWAGC 83 MHz, unmodulated. The input such that the pin 2 voltage is 2.0 V or below. (When the keyed AGC is set to 4.0 V.) 100 106 112 dBµ Conversion gain Oscillator buffer output A.V VOSCBUFFFM 83 MHz, 80 dBµ, unmodulated. The FE CF output 19 30 48 mVrms No input 260 370 480 mVrms [NC Block] NC input (pin 30) Gate time τGATE1 Noise sensitivity NC effect SN SN-NC f = 1 kHz, for a 1-µs, 100-mV p-o pulse 55 µs The level of a 1 = kHz, 1-µs pulse input that starts noise canceller operation. Measured at pin 30. 40 mVp-o The pulse rejection effect provided by the noise canceller. For a repeated 1-µs wide pulse, frequency = 10 kHz, 150 mV p-o. The ratio of the FM mode pin 15 output referenced to the AM mode pin 15 output (effective value) 5 [Multipath Rejection Circuit] MRC input (pin 27) MRC output MRC operating level VMRC MRC-ON V24 = 5 V 2.2 2.3 2.4 V The pin 32 input level at f = 70 kHz such that pin 24 goes to 5 V and pin 27 goes to 2 V 10 15 20 mVrms [AM Characteristics] AM ANT input Practical sensitivity S/N-30 1 MHz, 30 dBµ, fm = 1 kHz, 30% modulation, pin 15 20 Detector output VO-AM 1 MHz, 74 dBµ, fm = 1 kHz, 30% modulation, pin 15 85 120 170 mVrms VO-AM31 1 MHz, 74 dBµ, fm = 1 kHz, 30% modulation, pin 31 75 110 150 mVms VAGC-FOM 1 MHz, 74 dBµ, referenced to the output, the input amplitude such that the output falls by 10 dB. Pin 15 56 61 66 dB 47 Pin 31 detector output AGC F.O.M. Signal-to-noise ratio S/N-AM 1 MHz, 74 dBµ, fm = 1 kHz, 30% modulation Total harmonic distortion THD-AM 1 MHz, 74 dBµ, fm = 1 kHz, 80% modulation Signal meter output Oscillator buffer output Wide band AGC sensitivity SD sensitivity IF buffer output dB 52 dB 0.3 1 % V VSM AM-1 No input 0.0 0.2 0.5 VSM AM-2 1 MHz, 130 dBµ, unmodulated 3.8 4.8 6.2 No input, the pin 5 output 185 230 W-AGCsen1 1.4 MHz, the input when V46 = 0.7 V 83 89 95 W-AGCsen2 1.4 MHz, the input when V46 = 0.7 V (seek mode) 74 80 86 dBµ SD-sen1 AM 1 MHz, the ANT input level such that the IF counter output turns on. 26 32 38 dBµ SD-sen2 AM 1 MHz, the ANT input level such that the SD pin goes to the on state. 26 32 38 1 MHz, 74 dBµ, unmodulated. The pin 23 output 200 290 VOSCBUFF AM1 VIFBUFF-AM V mVrms dBµ dBµ 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 200 kΩ. * 2. When the resistor between pin 58 and ground is 30 kΩ. No. 5724-3/38 LA1780M Test Conditions Parameter Current drain Demodulation output Pin 31 demodulation output Channel balance Symbol Switch states SW1 SW2 SW3 SW4 SW5 SW6 SW7 SW8 SW9 SW10 ICCO-FM ON b OFF b — ON OFF OFF ON — VO-FM ON b OFF b — ON OFF OFF ON — VO-FM31 ON b OFF b — ON OFF OFF ON — CB ON b OFF b — ON OFF OFF ON — THD-FMmono 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 1 Att-1 ON b OFF b — ON OFF OFF ON — Muting attenuation 2 Att-2 ON b OFF b — ON OFF OFF ON — Muting attenuation 3 Att-3 ON b OFF b — ON OFF OFF ON — Separation ON b OFF b — ON OFF OFF ON — ST-ON ON b OFF b — ON OFF OFF ON — Total harmonic distortion Separation Stereo on level Stereo off level ST-OFF ON b OFF b — ON OFF OFF ON — 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 — Vi-lim ON b OFF b — ON OFF OFF ON ON Main total harmonic distortion Input limiting voltage Muting sensitivity Vi-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 1 VSM FM-1 ON b OFF b — ON OFF OFF ON — Signal meter output 2 VSM FM-2 ON b OFF b — ON OFF OFF ON — Signal meter output 3 VSM FM-3 ON b OFF b — ON OFF OFF ON — Signal meter output 4 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 — — VOSCBUFFFM ON a ON b — ON OFF OFF — — τGATE1 ON — OFF a — ON OFF OFF — — SN ON — OFF a — ON OFF OFF — — SN-NC ON/OFF — OFF a — ON OFF OFF — — VMRC ON — OFF b — ON OFF OFF — — Oscillator buffer output Gate time 1 Noise sensitivity NC effect MRC output MRC operating level Practical sensitivity MRC-ON ON — OFF b — ON OFF OFF — — S/N-30 OFF — OFF b ON ON — — — — — 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 — — — — Detection output Signal-to-noise ratio S/N-AM OFF — OFF b ON ON — — — — Total harmonic distortion THD-AM OFF — OFF b ON ON — — — — Signal meter output 1 VSM AM-1 OFF — OFF b ON ON — — — — Signal meter output 2 VSM AM-2 OFF — OFF b ON ON — — — — Oscillator buffer output VOSCBUFF AM-1 OFF — OFF b ON ON — — — — Wide band AGC sensitivity 1 W-AGCsen 1 OFF — OFF b ON ON — — — — Wide band AGC sensitivity 2 W-AGCsen 2 OFF — OFF b ON ON — — — — SD sensitivity 1 SD-sen1 AM OFF — OFF b OFF OFF — — — — SD sensitivity 2 SD-sen2 AM OFF — OFF b OFF OFF — — — — IF buffer output VIFBUFF-AM OFF — OFF b OFF OFF — — — — No. 5724-4/38 LA1780M Block Diagram IF limiter amplifier No. 5724-5/38 LA1780M Function List FM Front End (Equivalent to the Sanyo LA1193) • Double input type double balanced mixer • Pin diode drive AGC output • MOSFET second gate drive AGC output • Keyed AGC adjustment pin • Differential IF amplifier • Wide band AGC sensitivity setting pin, and narrow band AGC sensitivity setting pin • Local oscillator FM IF • IF limiter amplifier • S-meter output (also used for AM) 6-stage pickup • Multipath detection pin (shared FM signal meter) • Quadrature detection • AF preamplifier • AGC output • Band muting • Weak input muting • Soft muting adjustment pin • Muting attenuation adjustment pin • IF counter buffer output (also used for AM) • SD (IF counter buffer on level) adjustment pin • SD output (active high) (also used for AM) Noise Canceller • High-pass filter (first order) • Delay circuit based low-pass filter (fourth order) • Noise AGC • Pilot signal compensation circuit • Noise sensitivity setting pin • Function for disabling the noise canceller in AM mode Multiplex Functions • Adjustment-free VCO circuit • Level follower type pilot canceller circuit • HCC (high cut control) • Automatic stereo/mono switching • VCO oscillation stop function (AM mode) • Forced monaural • SNC (stereo noise controller) • Stereo display pin • Anti-birdie filter AM • Double balanced mixer (1st, 2nd) • IF amplifier • Detection • RF AGC (narrow/wide) • Pin diode drive pin • IF AGC • Signal meter output (also used for FM) • Local oscillator circuits (first and second) • Local oscillator buffer output • IF counter buffer output (also used by the FM IF) • SD (IF counter buffer on level) adjustment pin • SD output (active high) (also used for AM) • Wide AGC • Detection output frequency characteristics adjustment pin (low cut, high deemphasis) • AM stereo buffer MRC (multipath noise rejection circuit) AM/FM switching output (linked to the FM VCC) No. 5724-6/38 LA1780M Pin Descriptions Pin No. Function Description Equivalent circuit 62 pin 1 Antenna damping drive An antenna damping current flows when the RF AGC voltage (pin 2) reaches VCC-VD. 2 RF AGC Used to control the FET second gate. 3 F.E.GND 4 OSC Oscillator connection The transistor and capacitors required for the oscillator circuit are integrated on the chip. 7 AM OSC AM first oscillator This circuit can oscillator up to the SW band. An ALC circuit is included. Continued on next page. No. 5724-7/38 LA1780M Continued from preceding page. Pin No. Function Description 8 9 Noise AGC sensitivity AGC adjustment After setting up the medium field (about 50 dBµ) sensitivity with the noise sensitivity setting pin (pin 8), set the weak field (about 20 to 30 dBµ) sensitivity with the AGC adjustment pin (pin 9) 11 12 Memory circuit connection Memory circuit connection Recording circuit used during noise canceller operation. Equivalent circuit Differential amp 13 Pilot input Pin 13 is the PLL circuit input pin. 14 N.C, MPX, MRC, GND Ground for the N.C., MPX, and MRC circuits. Gate circuit Continued on next page. No. 5724-8/38 LA1780M Continued from preceding page. Pin No. Function Description MPX output (left) MPX output (right) Deemphasis 50 µs: 0.015 µF 75 µs: 0.022 µF 17 Pilot canceller signal output Adjustment is required since the pilot signal level varies with the sample-to-sample variations in the IF output level and other parameters. 18 Pilot canceller signal output Pin 18 is the output pin for the pilot canceller signal. 15 16 Equivalent circuit Continued on next page. No. 5724-9/38 LA1780M Continued from preceding page. Pin No. Function Description Equivalent circuit Composite signal 19 Separation adjustment pin 20 VCO 21 22 PHASE COMP. PHASE COMP. Use a trimmer to adjust the subdecoder input level. (The output level is not modified in mono and main modes.) The oscillator frequency is 912 Hz. KBR-912F108 (Kyocera Corporation) CSB-912JF108 (Murata Mfg. Co., Ltd.) Continued on next page. No. 5724-10/38 LA1780M Continued from preceding page. Pin No. 23 Function IF counter buffer seek/stop switching Description This pin functions both as the IF counter buffer (AC output) and as the seek/stop switch pin. The voltage V23 switches between the following three modes. During FM reception: 5 V: Seek mode 2.5 V: Forced SD mode 0 V: Reception mode AM reception (two modes: 0 and 5 V) 5 V: Seek mode 0 V: Reception mode Equivalent circuit IF counter buffer SD circuit Forced SD: 2.5 V FM S-meter 24 32 AM/FM signal meter Dedicated FM signal meter Fixed-current drive signal meter output AM S-meter In AM mode, pin 32 outputs a 1-mA current. Thus the HCC circuit is turned off. Outputs a 1-mA current during AM reception 26 Stereo indicator for the SD pin FM reception: the voltage V23 switches between three modes as follows. 5 V: The SD pin operates linked to the IF counter buffer. 2.5 V: Forced SD mode: operates as the SD pin. 0 V: Reception mode: stereo indicator AM reception: (two modes: 0 and 5 V) 5 V: Operates as the seek SD pin. 0 V: Reception mode. Not used. Stereo indicator Seek/stop switching Continued on next page. No. 5724-11/38 LA1780M Continued from preceding page. Pin No. 27 Function MRC control voltage time constant Description Equivalent circuit The MRC detector time constant is determined by a 1-kΩ resistor and C2 when discharging and by the 7-µA current and C2 when charging. Pin 28 28 SNC control input The sub-output is controlled by a 0 to 1-V input. The high band frequency output is controlled by a 0 to 1-V input. 29 HCC control input It can also be controlled by the MRC output. Use a resistor of at least 100 kΩ when controlling with the pin 32 FM S-meter signal. MRC input Continued on next page. No. 5724-12/38 LA1780M Continued from preceding page. Pin No. Function Description Equivalent circuit FM detector output 30 31 32 Noise canceller input Pin 30 is the noise canceller input. The input impedance is 50 kΩ. AM/FM detector output Pin 31 is the AM and FM detector output In FM mode, this is a lowimpedance output. In AM mode, the output impedance is 10 kΩ. To improve the low band separation, use a coupling capacitor of over 10 µF. IF S-meter output and MRC DC input AM detector Noise canceller FM S-meter output block MRC AC input block Adjust the external 1-kΩ resistor to attenuate the MRC AC input and control the circuit. MRC input •The muting time constant is determined by an external RC circuit as described below. Attack time: TA = 10 kΩ × C1 Release time: TR = 50 kΩ × C1 33 Mute drive output •Noise convergence adjustment The noise convergence can be adjusted when there is no input signal by inserting a resistor between pin 33 and ground. •Muting off function Ground pin 33 through a 4-kΩ resistor. Band muting SD circuit Continued on next page. No. 5724-13/38 LA1780M Continued from preceding page. Pin No. Function Description Equivalent circuit •The resistor R1 determines the width of the band muting function. Increasing the value of R1 narrows the band. Reducing the value of R1 widens the band. 34 35 36 37 AGC QD output QD input VREF Quadrature detector •Null voltage When tuned, the voltage between pins 34 and 37, V34 – 37, will be 0 V. The band muting function turns on when |V34 – 37| ≥ 0.7 V. V37 = 4.9 V IF limiter amplifier Band muting 38 FM SD ADJ A 130-µA current flows from pin 38 and, in conjunction with the external resistance R, determines the comparison voltage. Comparator S-meter S-meter 39 Keyed AGC AM stereo buffer The keyed AGC operates when the voltage created by dividing the pin 24 S-meter output voltage by the 6.4 and 3.6 kΩ resistors becomes lower than the voltage determined by the resistor between pin 39 and ground. Comparator This pin also is used as the AM stereo IF buffer pin. Continued on next page. No. 5724-14/38 LA1780M Continued from preceding page. Pin No. 41 Function HCC capacitor Description Equivalent circuit The HCC frequency characteristics are determined by the external capacitor connected at this pin. This pin is used to change the frequency characteristics of the unneeded audio band under 100 Hz in AM mode to produce a clear audio signal. 42 AM L.C. pin Note: The LC capacitor must be connected between this pin and VCC (pin 40). This is because the detector circuit operates referenced to VCC. The cutoff frequency fC is determined by the following formula. fC = 1/2π × 50 k × C 43 Pilot detector Inserting a 1-MΩ resistor between pin 43 and VCC will force the IC to mono mode. Continued on next page. No. 5724-15/38 LA1780M Continued from preceding page. Pin No. 44 Function IF AGC Description Equivalent circuit Q1: Used for time constant switching during seeks. τ = 2.2 µF × 300 k • Seek τ = 2.2 µ × 10 The external capacitors are connected to VCC. This is because the IF amplifier operates referenced to VCC. Pin 40 VCC Pin 40 VCC 45 IF output The IF amplifier load 46 AM antenna damping drive output Wide band AGC input I46 = 6 mA (maximum) This is the antenna damping current. Continued on next page. No. 5724-16/38 LA1780M Continued from preceding page. Pin No. 47 Function FM muting on level adjustment Description Equivalent circuit Modify the value of the external resistor to adjust the muting on level. Pin 24 48 57 RF AGC bypass RF AGC RF AGC rectification capacitor The low frequency distortion is determined as follows: Increasing C48 and C57 improves the distortion but makes the response slower. Reducing C48 and C57 aggravates the distortion but makes the response faster. 50 51 IF bypass FM IF input Due to the high gain of the limiter amplifer, care must be taken when choosing the grounding point for the limiter amplifer input capacitor to prevent oscillation. 52 IF input The input impedance is 2 kΩ. Inverter Antenna damping For AGC use Continued on next page. No. 5724-17/38 LA1780M Continued from preceding page. Pin No. Function Description Equivalent circuit • Input and output pin or the first IF amplifier • Inverting amplifier 53 56 IF amplifier output IF amplifier input V56 = 2 V Input impedance: RIN = 330 Ω V53 = 5.3 V Output impedance ROUT = 330 Ω Pin 40 VCC Pin 40 VCC 54 49 Mixer output: 130 µA Mixer input The mixer coil connected to the pin 54 mixer output must be wired to VCC (pin 40). The pin 49 mixer input impedance is 330 Ω Pin 62 VCC Pins 55 and 58 include built-in DC cut capacitors. The AGC on level is determined by the values of the capacitors C1 and C2. 55 W-AGC IN AM SD ADJ 58 N-AGC IN Muting attenuation adjustment pin Pin 55 functions as the SD sensitivity adjustment pin in AM mode. The output current I55 is 50 µA, and V55 varies depending on the value of the external resistor. The SD function operates by comparing V55 with the S-meter voltage. Signal meter Continued on next page. No. 5724-18/38 LA1780M Continued from preceding page. Pin No. Function Description Equivalent circuit Double balanced mixer Pins 60 and 61 are the mixer 10.7-MHz output 59 60 63 64 Mixer output Mixer input Pins 63 and 64 are the mixer input. This is an emitter insertion type circuit, and the amount of insertion is determined by the capacitors C1 and C2. Note:The lines for pins 63 and 64 must be kept separated from the lines for pins 60 and 61. Pin 62 functions both as the FM front end VCC and the AM/FM switching circuit. 6 Front end VCC AM/FM switching V6 voltage AM/FM switching circuit Mode When 8 V → FM OPEN → AM To RF Amp. 62 1st MIX INPUT First mixer input The input impedance is about 10 kΩ. AM 2nd OSC Crystal oscillator circuit The Kinseki, Ltd. HC-49/U-S and a CL of 20 pF must be used. To 2nd MIX 10 Continued on next page. No. 5724-19/38 LA1780M 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 Pin 3 VCC for the FM front end and AGC blocks, and the AM/FM switching pin 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 Pin 6 voltage Mode 8 FM OPEN AM 4. Relationship between Pin 23 and Pin 26 • FM mode Pin 26 functions as both the stereo indicator and the SD pin. Pin 23: DC-input seek/stop pin (control pin) AC output IF counter buffer pin IF counter buffer Between 0 and a few thousand Ohms. The Pin 23 Control Function and the Relationship between Pin 23 and Pin 26 SW1 SW2 Pin 23 voltage Pin 26 OPEN OPEN 5V IF counter buffer on Pin 26 SD ON OPEN 2.5 V OFF High-speed SD — ON Under 0.7 V OFF Stereo indicator No. 5724-20/38 LA1780M S-meter Larger R38 Smaller R38 V33 0.7 V or over V33 0.7 V or over On and functioning as SD IF counter buffer on Stereo Mono IF counter output off Used as RDS and similar function SD detection by switching this mode. Notes on FM SD Band muting Mute drive output S-meter IF counter buffer IF counter output No. 5724-21/38 LA1780M • AM mode S-meter Larger R55 Smaller R35 Pin 55: AM SD Adjustment Pin • Pins that support AM stereo To an AM stereo decoder 400-mV rms 450-kHz output Keyed AGC • To attenuate the pin 39 AC level: Add a capacitor between pin 39 and ground. For example, if a capacitor is added between pin 39 and ground, and pin 51 is attached, the AM IF output will be reduced by about 6 dB. No. 5724-22/38 LA1780M • Notes on the muting attenuation The resistor between pin 58 and ground switches the muting attenuation to one of three levels, –20, –30, and –40 dB. This is also related to the tuner’s total gain. R Mute ATT OPEN –20 dB 200k –30 dB 30k –40 dB If R33 is reduced, the attenuation will be reduced as listed in the table above. Muting time constants Attack: 10 k × C33 Release: 50 k × C33 Quadrature detector Limiter No. 5724-23/38 LA1780M • MRC circuit S-meter FM S-meter Noise amplifier fc = The MPF + AMP 70 kHz Required external transistor: 2SC536 or equivalent Reason: Since the LA1780M MRC is a simplified circuit, an OMRC level shifter is required. To SNC Pin 28 • If there is no AC noise on pin 32: V24 = V27 – VBE ↑ QMRC V27 will be about 2.5 V for an antenna input of 60 dBµ or higher. • Since the MRC noise amplifier gain is fixed, the MRC circuit is adjusted by reducing the AC input level. • The MRC circuit attack and release times are determined by the capacitor C27 on pin 27. Attack: 7 µA × C27 Release: 500 Ω × C27 5. FM Soft Muting Smaller R47 Larger R47 Larger R47 Smaller R47 By comparing the pin 47 mute on adjustment voltage to the S-meter voltage (V24), the muting on point can be adjusted. No. 5724-24/38 LA1780M • Noise canceller notes The characteristics of the noise canceller have been improved by implementing the circuit that determines the gate time in logic. In earlier noise canceller circuits, since the time constant was determined with an RC circuit such as the one shown in figure 5, the rise time was influenced by the RC circuit time constant as show in figure 6. This meant that the rise was delayed and the associated switching delay resulted in a reduction of the circuit’s ability to exclude noise. Figure 5 In the LA1780M, the rise time is made shorter by implementing the circuit that determines the gate time in logic. This allows the LA1780M to eliminate noise reliably. Figure 6 • Gain distribution (FM) This section analyzes the gain in each of the blocks in the LA1780M when the Sanyo recommended circuit is used. Test conditions Ambient temperature: 26°C Antenna and mixer input frequency: 98.1 MHz First and second IF input frequency: 10.7 MHz Input levels when VSM = 2 V were measured to be: Antenna input: 19 dBµ Mixer input: 30 dBµ First IF input: 42 dBµ Second IF input: 60 dBµ These values allow the gains in each block to be calculated as follows. RF gain: 11 dB Mixer gain: 12 dB No. 5724-25/38 LA1780M AM This section analyzes the gain in each of the blocks in the LA1780 when the Sanyo recommended circuit is used. Test conditions Ambient temperature: Antenna and mixer 1 input frequency: Mixer 2 input frequency: IF and detector input frequencies: An AM dummy is attached. 26°C 1 MHz 10.71 MHz 450 kHz When an input level such that the output becomes –35 dBm is determined, the I/O characteristics of each stage were determined to be as follows: Antenna input: 9.5 dBµ Mixer 1 input: 25.6 dBµ Mixer 2 input: 29.5 dBµ IF input: 36.0 dBµ Detector input: 102.0 dBµ These values allow the gains in each block to be calculated as follows. RF gain: 16.1 dB Mixer 1 gain: 3.9 dB Mixer 2 gain: 6.5 dB IF gain: 66.0 dB No. 5724-26/38 LA1780M • Input circuits used at each stage [FM] Mixer input First IF input Actual measurement IF input [AM] First mixer input IF input Second mixer input Detector input No. 5724-27/38 LA1780M • 3D AGC (keyed AGC) settings S-meter VS-meter · The antenna damping function operates by providing the pin diode antenna damping current from the pin when the pin 2 voltage becomes equal to VCC – VBE. · The noise AGC circuit operates as follows: When the pin 39 voltage is greater than (6.4/3.6) times the pin 24 voltage, the ACG circuit is off. When the pin 39 voltage is less than (6.4/3.6) times the pin 24 voltage, the ACG circuit is on. No. 5724-28/38 LA1780M AM AGC System The LA1780M RF AGC is picked up from three locations. · The wide AGC determined by Rw · The middle AGC picked up from the pin 49 second mixer input The operating bandwidth is 150 kHz to 180 kHz (the bandwidth of the 10.7 MHz CF) · The narrow AGC picked up from pin 52 The operating bandwidth is 7 kHz (the bandwidth of the 450 kHz CF) AGC on level AM AGC Frequency Characteristics Wide AGC Operates for wide-band interfering stations. Wide AGC Operates for wide-band interfering stations. Middle AGC Operates for interfering stations that are ±70 kHz from the received frequency. Middle AGC Operates for interfering stations that are ±70 kHz from the received frequency. Narrow AGC Operates at the received frequency. Frequency, — Hz No. 5724-29/38 LA1780M • Sample AM application using the LC72144 and the LA1780M AM 1st IF Step FM IF 1 fOSC 10.25 MHz 10.7 MHz 10 K, 1 K 10.7 MHz 2 fOSC 10.35 MHz 10.8 MHz 9 K, 10 K 10.8 MHz No. 5724-30/38 LA1780M Crystal Oscillator Element (Kinseki, Ltd.) HC-49/U-S Frequency: 10.26 MHz Load capacitance: 20 pF Equivalent series resistance: 90 Ω Coil Specifications (SUMIDA ELECTRIC CO., LTD.) Application: Prototype number [AM Block] AM FILTER AM OSC AM IF1 (MIX) AM IF2 AM loading AM antenna input AM RF amplifier [FM Block] FM RF FM ANT FM OSC FM MIX FM DET Model number SA-1051 SA-359 SA-264 SA-1111 SA-1009 SA-1063 SA-1112 SA-265 SA-1062 SA-1048 RC875-222J Y-5G (For the first mixer input: 5 mm diagonal) S-7LB PG78 PG57 (5 mm, high reliability) P-5DJ (5 mm diagonal) PG78 PG57 (5 mm, high reliability) P-5DJ (5 mm diagonal) MG78 MG78 RC875 SA-1060 SA-1061 SA-1052 SA-266 SA-208 SA-360 S-7LDJ S-7LDJ S-7LDJ P-7LFJ (Double balanced mixer) QU-7L (Quadrature detector) QU57 (5 mm diagonal, quadrature detector) AM Block • SA-359 (AM FILTER) • SA-264 (AM IF1) ① – ② 30T ⑥ – ④ 19T ② – ③ 151T 0.05 UEW ① – ② 16T ② – ③ 16T 0.08 UEW • SA-1063 (AM IF2) • SA-1062 (AM loading) ① – ② 75T ② – ③ 75T 0.05 UEW ① – ③ 850T 0.05 UEW • SA-1048 (AM ANT IN) ① – ③ 74T 0.07 UEW No. 5724-31/38 LA1780M FM Block • SA-1060 (FM RF) • SA-1061 (FM ANT) ⑥ – ④ 1T 0.10 UEW ③ – ① 3T ③ – ① 3T 0.16 UEW • SA-1052 (FM OSC) ⑥ – ④ 3T ⑥ – ④ 3T 0.16 UEW • SA-266 (FM MIX) ⑥ – ① 2T ⑥ – ① 2T 0.18 UEW ③ – ① 3T 1 ⑥–②6 T 2 1 ②–④6 T 2 0.10 UEW • SA-208 (FM DET) 1 T 4 0.08 UEW 1 ③ – ① 70 T 4 0.06 UEW ④ – ③ 18 Coil Specifications (Toko INC) [AM Block] AM ANT ANT Choke MIX LPF AM 2nd MIX AM OSC AM IFT2 [FM Block] AM, FM, MIX FM DET FM ANT FM RF FM OSC Toko Part No. 269ANS-0720 385BNS-027Z 187LY-222K A286LBIS-15327 L7TCS-3039A V666SNS-213BY 7PSG-5002 3710H-1108FYH DM600DEAS-8407 666SNS-219NK 666SNS-218AQ V666SNS-205APZ No. 5724-32/38 LA1780M FM Block • 3710H-1108FYH (AM • FM • MIX) • DM600DEAS-8407GLF (FM DET) ③ – ① 13T 1 ③–⑤6 T 2 1 ⑤–①6 T 2 ⑥ – ④ 2T 0.07ø ZUEW • 666SNS-219NK (FM ANT) 1 T 2 1 ⑥–④2 T 2 ③ – ① 59T 0.07ø ZUEW ⑥ – ③ 19 • 666SNS-218AQ (FM RF) 1 T 2 ⑥ – ④ 1T 0.1ø ZUEW 1 T 2 0.1ø ZUEW ③–①2 ④–⑥2 • V666SNS 205APZ (FM OSC) ⑥–①2 0.12ø ZUEW AM Block • 269ANS-072Z (AM ANT) ① – ③ 60T 0.06 3UEW • 187LY-222K (Choke) • 385BNS-027Z (ANT) ① – ③ 60T 0.06ø 3UEW • A286LBIS-15327 (MIX LPF) 243 0.1ø ZUEW No. 5724-33/38 LA1780M • L7TCS-3039A (AM 2nd MIX) ① – ③ 152T ① – ② 25T ② – ③ 127T ⑥ – ④ 16T 0.05ø 3UEW • V666SNS-213BY (AM OSC) 1 T 2 1 ③ – ② 12 T 4 1 ② – ① 12 T 4 0.1ø ZUEW ③ – ① 24 • 7PSG-500Z (AM IFTZ) ① – ③ 148T ① – ② 74T ② – ③ 74T 0.05ø 3UEW No. 5724-34/38 LA1780M FM I/O Characteristics Output, noise, AM output, LR output — dB HCC, SNC, RF AGC, muting voltage, Smeter voltage, VSM — V FM I/O Characteristics Antenna input, — dBµ FM Distortion FM Sensitivity Suppression Output, noise — dB Total harmonic distortion, THD — % Antenna input, — dBµ Antenna input, — dBµ FM Gain Distribution (1) FM Gain Distribution (2) DCV — V Output, noise, AM output — dB Antenna input, — dBµ Input, — dBµ Mixer I/O Characteristics First IF I/O Characteristics Mixer output — dBµ First IF output — dBµ Input, — dBµ Mixer input, — dBµ First IF input, — dBµ No. 5724-35/38 LA1780M AM I/O Characteristics Output, noise — dB Output — dB First IF output — dB First IF Frequency Characteristics. Antenna input, — dBµ AM Distortion AM DC Characteristics AGC, S-meter voltage — V Total harmonic distortion, THD — % Frequency, — MHz Antenna input, — dBµ FM Antenna Input Temperature Characteristics (1) FM Antenna Input Temperature Characteristics (2) Output - mV rms S/N, AM output — dB AGC on, separation, input level — dBµ Antenna input, — dBµ Separation Ambient temperature, Ta — °C FM Antenna Input Temperature Characteristics (3) FM Antenna Input Temperature Characteristics (4) Antenna input — dBµ Separation, Sep — dB Ambient temperature, Ta — °C Ambient temperature, Ta — °C Ambient temperature, Ta — °C No. 5724-36/38 LA1780M FM Antenna Input Temperature Characteristics (6) S-meter voltage, VSM — V Total harmonic distortion, THD — % FM Antenna Input Temperature Characteristics (5) Ambient temperature, Ta — °C AM Antenna Input Temperature Characteristics (2) Total harmonic distortion, THD — % S-meter voltage, VSM — V AGC on level — dBµ AGC FOM, S/N, QS, SD sensitivity — dBµ Ambient temperature, Ta — °C AM Antenna Input Temperature Characteristics (1) Ambient temperature, Ta — °C AM Antenna Input Temperature Characteristics (3) FM Soft Muting (1) Output — mV rms Output, noise — dB Ambient temperature, Ta — °C Antenna input, — dBµ FM Soft Muting (2) FM Soft Muting (3) Output — dB Output, noise — dB Output — dB Ambient temperature, Ta — °C Antenna input, — dBµ Antenna input, — dBµ No. 5724-37/38 LA1780M With a 10-pF capacitor connected to pin 58 Frequency, — MHz AM AGC Frequency Characteristics AGC on level — dBµ AGC on level — dBµ AM AGC Frequency Characteristics Frequency, — Hz Specifications of any and all SANYO 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. SANYO Electric Co., Ltd. strives to supply high-quality high-reliability products. However, any and all semiconductor products fail with some probability. It is possible that these probabilistic failures could give rise to accidents or events that could endanger human lives, that could give rise to smoke or fire, or 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 products (including technical data, services) described or contained herein are controlled under any of applicable local export control laws and regulations, such products must not be exported without obtaining 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 permission of SANYO Electric 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 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. 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, 2000. Specifications and information herein are subject to change without notice. PS No. 5724-38/38