## Overview of LC75813ES-T The **LC75813ES-T** is a high-performance, general-purpose LCD display driver IC manufactured by ON Semiconductor (formerly Sanyo). It is primarily designed for applications requiring the control of dot-matrix or segmented LCD panels, such as car stereos, household appliances, and industrial instrumentation. --- ### Key Technical Specifications | Parameter | Specification | | :--- | :--- | | **Driver Type** | 1/3 to 1/4 Duty LCD Driver | | **Maximum Segments** | Up to 344 segments (in 1/4 duty mode) | | **Supply Voltage ($V_{DD}$)** | 4.5V to 6.0V | | **Interface** | 3-wire Serial Interface (CCB) | | **Package** | QFP-64 / TQFP-64 | | **Display Mode** | Static, 1/2, 1/3, or 1/4 duty | --- ### Internal Functional Blocks The LC75813ES-T integrates several electronic components into a single silicon chip to manage display logic: 1. **Display Data RAM**: Stores the pattern data to be displayed on the LCD. This reduces the processing load on the host microcontroller (MCU). 2. **Clock Generator**: Contains an internal oscillation circuit. It can also be driven by an external clock. 3. **CCB Interface**: Uses a "Computer Control Bus" (Sanyo’s proprietary 3-wire serial protocol) involving `CE` (Chip Enable), `CL` (Clock), and `DI` (Data Input) pins. 4. **LCD Drive Bias Circuit**: Generates the necessary voltage levels for the LCD segments to ensure clear contrast and prevent ghosting. --- ### Pin Configuration Categories The pins of the LC75813ES-T can be categorized into four functional groups: | Group | Pins | Description | | :--- | :--- | :--- | | **Power Supply** | $V_{DD}, V_{SS}$ | Main logic power and ground. | | **MCU Interface** | $CE, CL, DI$ | Receives serial data from the microcontroller. | | **LCD Drive** | $S1 - S86$ | Segment output pins that connect to the LCD. | | **Common Drive** | $COM1 - COM4$ | Common pins used to multiplex the display. | --- ### Features and Benefits * **Power Saving**: Includes a "Sleep Mode" and "All-Segments-Off" function to minimize power consumption when the display is not active. * **Reduced Wiring**: The serial interface significantly reduces the number of connections required between the MCU and the driver. * **Flexible Multiplexing**: Supports various duty cycles, allowing engineers to choose between high segment counts (1/4 duty) or higher contrast (1/2 or 1/3 duty). * **Built-in Resistors**: Features internal bias resistors, reducing the need for external discrete components on the PCB. --- ### Typical Application Circuit Example When integrating the LC75813ES-T, the basic setup involves decoupling capacitors on the power lines and a connection to the MCU via three signal lines. ```c // Pseudo-code logic for initializing LC75813 via CCB void Init_LCD_Driver() { Send_CCB_Command(DISPLAY_ON); // Activate display Send_CCB_Command(DUTY_1_4); // Set to 1/4 duty cycle Clear_RAM(); // Clear internal display RAM } ```