Ordering number: EN 3507
Monolithic Linear IC
LA1136N, 1136NM, 1137N, 1137NM AM Tuners for Car Radios and Home Stereos
Overview The LA1136N/NM and LA1137N/NM are high-performance AM electronic tuner ICs offering sophisticated functions. They are especially suited for use in car radio and home stereo (antenna: loop) applications.
. MIX . OSC (with ALC) . IF amplifier . Detector . AGC (normal) . RF wide-band AGC . Auto search stop signal (Signal meter output) . Local oscillation buffer output . IF band switching circuit (for LA1136N only) . IF count buffer . Stop detector output (can be set independently) . Tweet prevention circuit . AGC (RF, IF) time constant switching circuit . IF AGC circuit . Pin-diode driver . AM stereo decoder IF output (for LA1136N only) . Circuit preventing incorrect seek operation
. Excellent cross modulation characteristic: Meets the . . . . . . . .
requirements for preventing not only adjacent-channel interference but also interference caused by all channels within broadcast band. Narrow-band signal meter output: Usable as auto search stop signal. Has linearity up to 100 dBµ. Local oscillation buffer output: Facilitates designing of electronic tuner system, frequency display, etc. OSC (with ALC): Improves tracking error because oscillation output is stabilized at a low level (350 mVrms: LA1137N) for varactor diode. MIX: Double-balanced differential MIX meeting the requirements for preventing spurious interference, IF interference. Good characteristic at high input: 130 dBµ input fm = 400 Hz 80%mod THD = 0.5% typ. High S/N: Good S/N at medium input (55 dB typ). Usable sensitivity: (S/N = 20 dB input): 25 dBµ (when using 2SK715 ) VCC variation compensation: Less variation in gain, distortion: 8 to 12 V
AM stereo capability (LA1136N only)
. IF band switching circuit on chip; controlled by . microcontroller for AM stereo; SUB S/N improved to Oscillating circuit . 6 dB for AM stereo decoder . IF output tweet characteristics: 10 dB increase, controlled by Improved . microcontroller modulation characteristics, especially Improved cross . . . . .
sensitivity suppression characteristics: 15 dB improvement, wide-band AGC operation even for SW band interference Improved low-frequency modulation distortion Improved temperature characteristics: S-meter, SD sensitivity Faster RF AGC response: RF: 1/3; IF: 1/8 (compared to predecessors) Improved capability for driving external RF AGC transistors: IB max = 200 µA Measures to prevent incorrect seek operation IF count buffer on chip; controlled by microcontroller Time constant switching circuit on chip for RF and IF AGC IF AGC clear circuit on chip Measures that prevent stopping one station too soon
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SANYO Electric Co.,Ltd. Semiconductor Bussiness Headquarters TOKYO OFFICE Tokyo Bldg., 10, 1 Chome, Ueno, Taito-ku, TOKYO, 110 JAPAN 93097HA(II)/4281TS(US) No.3507-1/28