LMC1983CIV / National Semiconductor (TI)

LMC1983CIV Datasheet with Chat AI

Hello, Please ask a question about LMC1983CIV Datasheet

# Example questions: ➢ What is the purpose of the loudness function and how does it attempt to compensate for human hearing characteristics?
➢ Describe the function of the intermetal serial bus (im bus) in communicating with the lmc1983, including the roles of the clk, data, and id lines.
➢ Explain how the tone control circuitry works in the lmc1983, detailing the role of external capacitors c2 and c3 and how their values affect the frequency response.

Part No.	LMC1983CIV
Manufacturer	NSC
Size	331 Kbytes
Pages	14 pages
Description	Digitally-Controlled Stereo Tone and Volume Circuit with Three Selectable Stereo Inputs

Datasheet Summary with AI

1. General Overview:

️· The LMC1983 is an integrated circuit designed for audio processing and control in stereo systems.
️· It incorporates features like input selection/muting, loudness control, bass/treble tone control, and digital input reading.
️· It utilizes an INTERMETAL (IM) bus for serial data communication with a microcontroller.

2. Features and Functionality:

️· Input Selection/Muting: Allows selection of three inputs (INPUT1, INPUT2, INPUT3) and includes a mute function.
️· Loudness Control: Compensates for the human ear's varying sensitivity to frequencies at different volume levels.
️· Bass/Treble Tone Control: Offers adjustable bass and treble frequencies with up to +12dB or -12dB boost/cut. Requires a few external capacitors (C2 & C3) for operation.
️· Digital Input: Can read digital inputs (Digital Input 1 and Digital Input 2) and relay their state via the IM bus.
️· Volume Control: Provides multiple volume levels, ranging from 0dB to -80dB attenuation.

3. INTERMETAL (IM) Bus Communication:

️· Structure: Three-wire bus (Clock, Data, Identity). Data line requires an external pull-up resistor.
️· Addressing: Responds to addresses from 01000000 (40H) through 01000111 (47H).
️· Data Transmission:
- Start with low levels on CLK and ID.
- Eight address bits are sent, followed by eight data bits.
- ID line is pulsed low to signal the end of transmission.
️· Data Structure: Table 1 details the structure of data for each function.

4. Tone Control Details:

️· Requires external capacitors (C2 & C3) to set tone frequencies.
️· The ratio of C2 and C3 influences the mid-frequency gain.
️· Changes to C2 & C3 alter turnover frequency.

5. Loudness Control Details:

️· Utilizes external components R1, R2, C4, and C5.
️· Allows for bass-only or full loudness control.

6. Key Components & External Requirements:

️· Capacitors (C2, C3): For tone control.
️· Resistor (External Pull-up): For the Data line on the IM bus.
️· Resistors & Capacitors (R1, R2, C4, C5): For loudness control.

In essence, the LMC1983 is a versatile IC designed to manage audio processing and control in a stereo system using a serial data interface.