RS485 트랜시버 모듈 -THVD1424
(RS485 7 CLICK)
개요
- 본 제품은 RS485 트랜시버 모듈 -THVD1424입니다.
- 풀 듀플렉스 RS485 트랜시버 THVD1424 칩을 기반으로 디자인된 제품입니다.
- 칩상에 120오옴 종단 저항을 포함하고 있으며, 설정 핀을 통해 종단 조항, slew rate control, half duplex/full duplex등의 설정이 가능합니다.
특징
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HOW DOES IT WORK?
RS485 7 Click is based on the THVD1424, a flexible RS-485 transceiver from Texas Instruments for asynchronous data transmissions. The THVD1424 has two termination resistors of nominal 120Ω, one across Y/Z and another across A/B. Both termination resistors are enabled or disabled using pins RET and TET pins of the mikroBUS™ socket, routed to the default positions of PWM and INT pins of the mikroBUS™ socket. Both termination resistors can be enabled or disabled, independent of the state of the driver or receiver. Termination is OFF if the device is unpowered or in thermal shutdown. Internal ESD protection circuits protect the transceiver against Electrostatic Discharges (ESD) according to IEC 61000-4-2 of up to ±8kV (Contact Discharge), ±15kV (Air Gap Discharge), and against electrical-fast-transients (EFT) according to IEC 61000-4-4 of up to ±4kV.
The THVD1424 RS-485 transceiver can be used in half-duplex or full-duplex RS-485 networks by populating an onboard R5 resistor. Full duplex mode is the default state of this board (with unpopulated R5 resistor), where Y and Z terminal pins are driver output pins, and A/B pins are receiver input pins. By populating the R5 resistor, Half duplex mode is activated where the driver and receiver share the same bus pins (Y/Z pins are both driver and receiver pins). The device state is then controlled via two mikroBUS™ pins labeled DE and RE (driver and receiver enable/disable), routed to the default positions of the AN and RST pins of the mikroBUS™ socket.
The THVD1424 can also be used in slow-speed or fast-speed RS485 networks by populating a slew rate control R10 resistor. By default, with the R10 resistor unpopulated, the maximum speed of operation for both driver and receiver is 20Mbps. By populating it, the maximum speed of operation for both driver and receiver is 500kbps, where the receiver path has an additional noise filtering feature enabled. The THVD1424 also has built-in protection features such as supply undervoltage, bus short-circuit, and thermal shutdown.
This Click board™ can operate with either 3.3V or 5V logic voltage levels selected via the VIO SEL jumper. This way, both 3.3V and 5V capable MCUs can use the communication lines properly. Also, the main power supply of the RS485 transceiver can be selected between 3.3V or 5V voltage levels selected via the VCC SEL jumper. The wide common-mode voltage range and low input leakage on bus pins make this Click board™ suitable for multi-point applications over long cable runs. However, the Click board™ comes equipped with a library containing easy-to-use functions and an example code that can be used, as a reference, for further development.
SPECIFICATIONS
Type RS485 Applications Can be used for industrial and multi-point applications over long cable runs On-board modules THVD1424 - full duplex RS485 transceiver from Texas Instruments Key Features Highly flexible, selectable power and logic voltage levels, configurable half and full duplex mode, pin-configurable 120Ω termination resistor on bus pins, configurable data rate, bus I/O protection, low power consumption, glitch-free power-up/power-down for hot plug-in capability, protection features, and more Interface GPIO,UART Compatibility mikroBUS Click board size M (42.9 x 25.4 mm) Input Voltage 3.3V or 5V