Introduction to LA7693X

The LA7693X is a highly integrated chip that combines a TV signal processor, microcontroller, and on-screen display (OSD) functionality. Its design simplifies system integration and enhances performance in various television applications. Below is an overview of its key features and pin functions.

TV Signal Processing Part:

• Fast AGC-controlled high gain IF amplifier with up to 65dB of gain across three stages.
• Integrated image IF carrier VCO oscillator eliminates the need for intermediate frequency transformers, improving reliability.
• PLL-based audio IF demodulation reduces internal carrier interference, enhancing sound quality.
• Built-in AV/TV switch and chrominance signal trap for improved color accuracy.
• Includes brightness delay line, hole correction, noise reduction, and black level extension circuits for superior image quality.
• PAL/NTSC/SECAM color decoding with a built-in SECAM decoder chip (LA7642), supporting all three major broadcast standards.
• 1H baseband delay circuit and automatic dynamic balance (AKB) system for consistent white balance.
• Field scanning circuit with dual automatic frequency adjustment and 50/60Hz recognition, ensuring stable picture size even without signal.

Microcontroller and Control Features:

• Three built-in oscillators: RC for system clock, VCO for system and OSD clocks, and external crystal for time base and PLL reference at 32.768kHz.
• CPU instruction cycle: 0.848μs; bus cycle: 0.424μs. Includes 32kB ROM, 16kB CGROM, 512B RAM, and 352×9 OSD RAM.
• 5-channel 8-bit DAC, 3-channel 7-bit PWM, two 16-bit timers, one 14-bit timer, and I²C-compatible interface for flexible control.
• Features ROM correction, 15 interrupt sources, and 9 vector interrupts for efficient system management.

OSD Display Capabilities:

• Supports 36×16 dot matrix display, with 36×8 visible area and 8×8 control range. Up to 252 characters can be displayed.
• Offers 16 foreground, background, and edge/shadow colors, with options for smooth, underline, and italic text styles.
• Capable of displaying Japanese, Chinese, and English characters for multilingual support.

LA7693X Pin Functions:

• Pin 1: SIF OUT – Audio IF output
• Pin 2: PIF AGC – Image IF AGC filtering
• Pin 3: SIF INPUT – Second audio IF input
• Pin 4: FM FILTER – Audio FM filtering
• Pin 5: FM OUT/AUDIO OUT – FM detection output
• Pin 6: AUDIO OUT – Audio output with I²C volume control
• Pin 7: SIF APC – Audio IF phase detector filtering
• Pin 8: IF VCC – IF unit power supply
• Pin 9: AUDIO IN-VMOUT – Audio input and VM modulation output
• Pin 10: ABL – Automatic brightness limit
• ... (Continued for all 64 pins)

Due to its software-configurable pins, the functionality of the LA7693X may vary depending on the manufacturer and application. This flexibility makes it suitable for a wide range of TV and multimedia systems.