LA7693X chip usage overview

Crystal oscillator

Quartz Oscillator 3225 20M OSC

LA7693X color TV special large-scale integrated circuit series chip, is a super TV chip launched by Japan Sanyo Company at the beginning of this century. The series introduced in China mainly include LA76930, LA76931, LA76932, which were adopted by Xiahua, Konka, TCL Ace and other companies.

Among them, LA76930 is used on Xoceco TS, TF, MT movement color TV, the model is still LA76930 after masking; used on the ace TCL-AT2116Y color TV, the model after the mask is 13 -WS9301-AOP; on the TCL-AT21266Y color TV Adopted, the model number is 13 -WS9302 -AOP.

LA76931 is mainly used by Konka, Ace TCL and Skyworth. Among them, Konka applies it to SA series color TVs. The representative models are T21SA120/236/267/026/027/, P21SA281/282/390, etc. CKP1504S; mainly used in Y12 movement on Ace TCL color TV, representative model has 21V88, re-masked model is 13-LA7693-17PR; Skyworth is applied to 6D92 movement with digital engine V12, such as Skyworth 29T61HT, mask The rear chip model is LA76931N-7F-4HD4B.

LA76932 is mainly used by the ace TCL company and applied to the Y movement, such as the TCL-AT2516Y/2916Y color TV. After re-masking, the model is 13-WS9303-AOP. After re-masking on the Y22 and other movements, the models are different. For example, the model re-masked on the N25B5 and N25B6B color TVs is 13-TOOY22-01MO1, and the model re-masked on the 29V88 color TV is 13-LA7693. -2NPRO.

The LA7693X has four built-in oscillators. The 33 and 34 external crystals and internal circuits form the system clock. The 50-pin external crystal oscillator and internal circuit form a 4.43MHz voltage-controlled oscillator. There is also a line voltage controlled oscillator with an oscillation frequency of 4 MHz and an image intermediate frequency carrier oscillator with an oscillation frequency of 38 MHz. The internal circuit structure of LA76930, LA76931, and LA76932 is basically the same. The main difference is that the ROM memory and the user RAM memory have different capacities. In addition, the external crystal frequency is different, among which LA76930, LA76931 clock external crystal frequency is 32kHz; LA76930, LA76931 is mainly used for 21-inch economical medium and small screen color TV. LA76932 external crystal frequency is 32.768kHz, 15 feet for the object pillow distortion correction output, 9 feet for VM modulation output, suitable for 25/29/34 inch large screen color TV. It is worth mentioning that the LA7693X series I / O port (ie 23 ~ 32 feet, 36 ~ 39 feet) function can be set by the company's software, even if the same model chip, its port function settings will be different, depending on the specific machine Type depends. The following table shows the I/O port functions of some models on the LA76930, LA76931, and LA76932. Please pay attention when servicing.

The Sanyo LA7693X series super chip actually integrates the original single-chip TV small signal processing LA76820 and the microprocessor LC85F4538 into the same VLSI, so it is called "super chip". The color TV assembled by the super chip has greatly improved integration, fewer peripheral components and wiring, which makes the whole machine more reliable and has a lower failure rate. At the same time, due to the large number of new materials and new technologies, the power consumption of the whole machine is greatly reduced, and the volume is smaller, which meets the requirements of today's green environmental protection.

Because the LA7693X uses updated brightness and chrominance processing technology, color reproduction and image resolution (sharpness) are higher, this type of color TV basically has DVD component signal terminals (ie, Y, Cr, Cb), watching DVD Get better image results when you play the disc.

In addition, the super chip color TV generally adopts a digital frequency synthesis high-frequency tuner, which makes the oscillation frequency of the machine more stable, the tuning is more accurate, and the running platform failure is not easy to occur.