The **LC75386NE-R** is a high-performance CMOS IC designed by SANYO (now part of ON Semiconductor). It is primarily used as an **Electronic Volume and Tone Control** processor for high-end audio systems, such as car stereos and home hi-fi equipment. --- ## 1. Technical Specifications Overview The LC75386NE-R integrates multiple audio processing functions into a single chip, controlled via a serial bus interface (CCB). | Feature | Specification | | :--- | :--- | | **Package** | QFP-64 (Quad Flat Package) | | **Supply Voltage (Vdd)** | 4.5V to 9.5V | | **Channels** | 2-Channel (Stereo) | | **Interface** | CCB (Computer Control Bus) | | **Input Selectors** | 5-channel stereo inputs | | **Total Harmonic Distortion** | 0.005% (typical) | --- ## 2. Core Functional Blocks The internal electronic architecture consists of several key stages: ### A. Input Selector & Gain * **Multi-channel Switching:** It features a 5-input selector. * **Input Gain:** Provides an initial gain stage (0dB to +18.75dB in 0.625dB steps) to normalize different input sources (CD, Tuner, Aux). ### B. Volume Control * **Independent Control:** Left and right channels can be controlled independently. * **Step Resolution:** 0 to –78.75 dB (in 0.625dB steps) plus a full "Mute" function. * **Zero-Cross Detection:** Features a zero-cross detection circuit to minimize "clicking" or "zipper noise" when changing volume levels. ### C. Tone & Equalizer Section * **Bass & Treble:** Standard ±10dB adjustment. * **Parametric EQ:** Often used for mid-range adjustments. * **Loudness:** Integrated loudness function to boost frequencies at low volumes. ### D. Output & Fader * **4-Channel Output:** Supports Front (L/R) and Rear (L/R) outputs. * **Fader Control:** Independent attenuators for the rear channels to adjust front-to-back balance. --- ## 3. Pin Configuration Categories The 64 pins are generally categorized into these functional groups: | Pin Type | Function | | :--- | :--- | | **Power Supply** | Vdd (Positive), Vss (Ground), Vref (Reference voltage). | | **Audio Inputs** | L1-L5 and R1-R5 (Stereo source inputs). | | **Audio Outputs** | FL, FR, RL, RR (Front and Rear outputs). | | **Control Bus** | CE (Chip Enable), CL (Clock), DI (Data In) - CCB Protocol. | | **Filter Pins** | External capacitor connections for Treble, Bass, and Loudness curves. | --- ## 4. Typical Application Circuit The IC acts as the "brain" between the source (Bluetooth module/CD player) and the power amplifier. ```c [Source] ----> [LC75386NE-R Inputs] | (CCB Serial Control) <---- [Microcontroller] | [Power Amp] <---- [LC75386NE-R Outputs] ``` --- ## 5. Key Advantages 1. **Low Noise:** High S/N ratio suitable for high-fidelity audio. 2. **Integrated Filters:** Built-in switched-capacitor filters reduce the need for many external components. 3. **High Integration:** Replaces dozens of discrete op-amps and potentiometers. ---