Views: 500 Author: Site Editor Publish Time: 2020-09-30 Origin: Site
LED display repair starter chip of 74HC245
Overview: 74HC245 is a three-state output, eight-way signal transceiver, mainly used in display products, and other consumer electronics products to increase the drive. Commonly understood as a signal amplifier, the IC receives the signal and then output as is (similar to network relay).
1, using CMOS process
2, wide voltage operating range: 3.0V-5.0V
3、Bidirectional three-state output
4, eight-wire bidirectional transceiver
In the current market of LED display unit board from the input interface, the signal will enter HC245, and then output to the corresponding IC. monochrome display is generally a 245 is sufficient, full-color display due to 75 interface into the data is more, 245 port is not enough, generally more than 2 chips.
HC245 chip, the chip's own enable port OE (pin 19) must be separated from the whole board OE signal, just started many friends will confuse the two. The chip's own OE pins determine whether the chip is working properly. And DIR (pin 1) pins determine the direction of the input and output.
So the 245 most important pins to be concerned about are DIR pin 1, OE pin 19, VDD pin 20 and GND pin 10.
Actual case analysis: the unit board HUB interface data to see whether it enters the A side of the IC or B side, check whether the input and output are consistent.