LMC1982 National Semiconductor, LMC1982 Datasheet
LMC1982
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LMC1982 Summary of contents
Page 1
... There are two digital inputs for easy interface to other audio peripherals such as stereo decoders. The LMC1982 is designed for line level input signals (300 mV–2V) and has a maximum gain of −0.5 dB. Volume is set at minimum and tone controls are flat when supply voltage is first applied ...
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... ESD Susceptability (Note 5) + GND − 0. 0.2V Operating Ratings 5 mA Temperature Range 20 mA LMC1982CIN, LMC1982CIV 500 mW Supply Voltage Range (V +125˚C −65˚C to +150˚ kHz, input signal (300 mV) applied to INPUT 1, volume = 0 dB, bass = IN Conditions Clipping Level (1,.0% THD), Select Out (Pins 6, 23) Left and Right channels ...
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Electrical Characteristics + The following specifications apply for V 0 dB, treble = 0 dB, enhanced stereo is off, and loudness is off unlessotherwise specified. All limits apply for T Symbol Parameter Channel-to-Channel Volume Tracking Error Mute Attenuation Bass Gain ...
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... THD Constant) OUT DS011028-19 www.national.com (Continued) JMAX or the number given in the Absolute Maximum Ratings, whichever is lower. For the LMC1982CIN resistor. signal while the right inputs are grounded. rms Output Voltage vs Supply Voltage DS011028-14 CCIR Output Noise vs Volume Setting ...
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Typical Performance Characteristics Tone Control Response with Equal Bass and Treble Control Settings DS011028-22 (Continued) Loudness Response vs Frequency DS011028-23 5 Select Input Impedance vs Frequency DS011028-24 www.national.com ...
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... The controller must have open drain outputs used with external pull-up resistors. The data rate has a maxi- mum frequency of 1 MHz. The LMC1982 re- quires 16 bits of data to control or change a function: the first 8 bits select the LMC1982 and one of eight functions. The final eight bits set the function to a desired value ...
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... Figure 1 shows the connection diagram of a typical LMC1982 application. The LMC1982 has internal decoding logic that allows a mi- croprocessor (µP) or microcontroller (µC) to communicate di- rectly to the audio control circuitry through an INTERMETAL (IM) Bus interface. This three-wire interface consists of a bi-directional DATA line, a Clock (CLK) input line, and an Identity (ID) line ...
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... General Information (Continued) are serially shifted from the controller to the LMC1982. This is followed by 8 bits of function value data. Data present in the internal shift register is latched and the instruction is executed. Application Information INPUT SELECTOR The LMC1982’s input selector and mode control are shown in Figure 2 ...
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... C2 = 2(C3) and the tone controls set to “flat”, the frequency response will be flat and 20 kHz, and + kHz. The frequency where a tone control begins to deviate from a flat response is referred to as the turn-over frequency. With C3, the LMC1982’s treble turn-over frequency is nominally 9 www.national.com ...
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... The low and high frequency sensitivity decreases faster than the sen- sitivity to the mid-range frequencies as the acoustic level drops. The LMC1982’s loudness function can be used to help compensate for the decreased sensitivity by boosting the gain at low and high frequencies as the volume control attenuation increases (see the curve labeled “ ...
Page 11
... LMC1982’s desired functions. Each address bit is clocked in on the rising edge of CLK. The ID line is taken high after the eight bits of address data are received by the LMC1982. The controlling system continues toggling the CLK line eight more times. Data that determines the selected function’s op- ...
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... Application Information FIGURE 7. LMC1982’s INTERMETAL Serial Bus Timing www.national.com (Continued) 12 DS011028-11 ...
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... Physical Dimensions inches (millimeters) unless otherwise noted Order Number LMC1982CIN NS Package Number N28B 13 www.national.com ...
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... Italiano National does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and National reserves the right at any time without notice to change said circuitry and specifications. Order Number LMC1982CIV NS Package Number V28A 2. A critical component is any component of a life ...