Ordering number: EN 3507
Monolithic Linear IC
LA1136N, 1136NM, 1137N, 1137NM
AM Tuners for Car Radios and Home Stereos
Overview
Features
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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.
Excellent cross modulation characteristic: Meets the
requirements for preventing not only adjacent-channel
interference but also interference caused by all channels
within broadcast band.
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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 )
Functions
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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)
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VCC variation compensation: Less variation in gain,
distortion: 8 to 12 V
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AM stereo capability (LA1136N only)
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IF band switching circuit on chip; controlled by
microcontroller
Oscillating circuit for AM stereo; SUB S/N improved to
6 dB
IF output for AM stereo decoder
Improved tweet characteristics: 10 dB increase, controlled by
microcontroller
Improved cross modulation characteristics, especially
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
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Circuit preventing incorrect seek operation
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predecessors)
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Improved capability for driving external RF AGC transistors:
IB max = 200 µA
Measures to prevent incorrect seek operation
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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., 1-10, 1 Chome, Ueno, Taito-ku, TOKYO, 110 JAPAN
93097HA(II)/4281TS(US) No.3507-1/28