I tried to connect RS422--------USART3.
Using LTC1321, the circuit was designed as shown in the picture above.
But communication does not work.
Are the settings of pins 6, 7, and 18 and 19 incorrect?
Or do I really need to input -5V into VEE? Please give me some good ideas.
Hi Poterman,
The LTC1321 is a 5V dual-channel RS-232/RS-485 transceiver, so Vcc should be +5V. Vcc should also be tied with VDD, and a negative supply for VEE is required, please see picture from the datasheet below. Newer designs use charge plump or boost converter to generate positive and negative supply rails for dual/multi-protocol transceiver with single supply.
Your pin 6, 7, 18 and 19 connections set the part enabling both ports with RS-485 transceiver without loopback, and both RS-485 drivers are enabled.
Best,
Jane
