LA1140 Sanyo Semiconductor Corporation, LA1140 Datasheet
LA1140
Available stocks
Related parts for LA1140
LA1140 Summary of contents
Page 1
... Ordering number: EN 729E Overview The LA1140 system IC designed for FM car stereo receivers. It features versatile muting characteristics and allows receiver designers to realize the muting performance according to their design concept. Since the muting characteristics can be varied with a switch or a semi-fixed resistor, DX-Local switching will be accomplished with ease ...
Page 2
... V15-0 Signal meter output (2) V15-50 Signal meter output (3) V15-70 Signal meter output (4) V15-100 AGC output (1) V16-0 AGC output (2) V16-100 Offset voltage (1) V7-13 Offset voltage (2) V8-13 LA1140 Conditions max Pin 12 max Pin 25° 70°C Pin Pin 2 Pin 3 Pin 6 Pin 5 Pin 13 ...
Page 3
... AC Test Circuit Muting Characteristic The muting operation in the LA1140 is performed preamplifier, the gain of which varies continuously with control current, and a muting drive output circuit which supplies the control current. The gain of the AF preamplifier decreases with increasing gain control current applied to pin 6. However, the gain does not decrease further when the control current reaches approximately 120 µ ...
Page 4
... The general method to adjust the muting circuit of the LA1140 is: to set the signal input level required to actuate the muting circuit with the R16-G, to adjust the slope of the curve for the muting attenuation vs. antenna signal input with the R15-G, and to adjust the maximum muting attenuation (determined by setting the noise level at no signal) with the R5-G ...
Page 5
... Resistance between pin 5 and GND – 10.7 MHz 100 dBµ IN Pins 7 – 5.1 k Frequency detuned, f – kHz LA1140 Ambient temperature, Ta – ° 10.7 MHz, non-modulation Input voltage through Tuned, muting OFF 2 – 200 kHz detuned, muting OFF 3 – 200 kHz detuned, muting ON Input voltage, V (pin 1) – ...
Page 6
... Ambient temperature, Ta – ° 10.7 MHz CC Non-modulation Ambient temperature, Ta – ° Non-modulation Ambient temperature, Ta – °C LA1140 f = 10.7 MHz, non-modulation Quadrature signal, V11 – dBµ Ambient temperature, Ta – °C I CCO Ambient temperature, Ta – °C = 100 dBµ ...
Page 7
... Non-modulation Quiescent Ambient temperature, Ta – ° 100 dBµ, non-modulation Supply voltage, V – Supply voltage, V – LA1140 Quiescent Ambient temperature, Ta – °C Ambient temperature, Ta – °C Supply voltage, V Supply voltage 10.7 MHz Non-modulation – 10.7 MHz Non-modulation – ...
Page 8
... CC Supply voltage, V – 10.7 MHz Non-modulation I (quiescent) CCO Supply voltage, V – 10.7 MHz Non-modulation Quiescent Supply voltage, V – LA1140 Supply voltage, V Supply voltage, V Quiescent Supply voltage, V Quiescent Supply voltage, V – 100 dBµ IN Non-modulation – 10.7 MHz Non-modulation – ...
Page 9
... Proper cares in using LA1140 1) The detector transformers should be designed to develop a quadrature signal (pin 11) of higher than 175 mVrms (approximately 105 dBµ) under high antenna signal input. If the quadrature signal strength is less than 125 mVrms, the muting drive output (V14) cannot decrease to zero even in a strong signal strength. Furthermore, when the quadrature signal strength lies between 125 mV and 175 mV, the muting drive output may move from zero to plus under high temperature conditions ...
Page 10
... Sample Printed Circuit Pattern . Variations of muting characteristics with a resistor connected between pin 16 and GND varied. (Muting threshold level adjustment) ANT Input – dBµ LA1140 (Cu-foiled side Mute OFF Mute ON ANT Input – dBµ Demodulation output Noise No. 729-10/15 ...
Page 11
... ANT input – dBµ . Variations of muting characteristics with a resistor connected between pins 14 and 6 varied. (Slope adjustment 2 of the curve for muting attenuation vs. antenna signal input level) ANT input – dBµ LA1140 R Adjustment output Mute OFF Mute ON ANT input – dBµ ...
Page 12
... High Frequency Section of Car Radio and Car Stereo with Noise Canceller and FM Stereo Multiplexer Almost all noise under a medium and lower input signal strength can be rejected by processing the muting characteristic of the LA1140, the stereo noise control (SNC) characteristic and the high cut control characteristic of the LA3370. These examples are as follows: ...
Page 13
... Circuit Diagram Pilot cancel LA1140 Oscilloscope Unit (resistance: Ceramic oscillator , capacitance: F) No. 729-13/15 ...
Page 14
... ANT input – dBµ ANT input – dBµ Frequency characteristic of demodulation output by HCC ANT input = 10 dBµ Modulation frequency – Hz Signal meter output Separation ANT input – dBµ LA1140 SNC Characteristic V Stereo Monaural ANT input – dBµ HCC Characteristics V Hcc OFF, monaural ANT input – ...
Page 15
... SANYO believes information herein is accurate and reliable, but no guarantees are made or implied regarding its use or any infringements of intellectual property rights or other rights of third parties. This catalog provides information as of September, 1997. Specifications and information herein are subject to change without notice. LA1140 Type Number Package Pri ...