Overview
The ADM485JR, produced by Analog Devices Inc., is a differential line transceiver designed for high-speed bidirectional data communication on multipoint bus transmission lines. It complies with EIA standards RS-485 and RS-422, making it suitable for balanced data transmission. The device operates from a single 5 V power supply and features a BiCMOS process, combining low power CMOS with fast switching bipolar technology. This transceiver includes a differential line driver and a differential line receiver, both of which can be enabled independently, and it supports data rates up to 5 Mbps.
Key Specifications
| Parameter | Rating/Value |
|---|---|
| VCC | −0.3 V to +7 V |
| Driver Input (DI) | −0.3 V to VCC + 0.3 V |
| Control Inputs (DE, RE) | −0.3 V to VCC + 0.3 V |
| Receiver Inputs (A, B) | −9 V to +14 V |
| Driver Outputs (A, B) | −9 V to +14 V |
| Receiver Output | −0.5 V to VCC + 0.5 V |
| Data Rate | Up to 5 Mbps |
| Bus Common-Mode Range | −7 V to +12 V |
| Driver Propagation Delay | 10 ns typical |
| Receiver Propagation Delay | 15 ns typical |
| Package | SOIC-8 |
| Power Dissipation | 900 mW (8-Lead MSOP) |
| Thermal Impedance | 206°C/W |
Key Features
- Meets EIA RS-485 and RS-422 standards
- Single 5 V power supply
- High-speed, low power BiCMOS technology
- Thermal shutdown protection and short-circuit protection
- High-Z outputs when powered off or disabled
- Fail-safe receiver feature for unconnected inputs
- ESD protection on all inputs and outputs
- High source and sink current capability on driver outputs
- Supports up to 32 transceivers on a bus
Applications
- Low power RS-485 systems
- DTE/DCE interface
- Packet switching
- Local area networks (LANs)
- Data concentration and data multiplexers
- Integrated services digital network (ISDN)
- Communication networks (optical fiber, wireless, satellite)
- Automotive electronics (vehicle entertainment, navigation, intelligent driving assistance)
- Industrial Internet of Things (smart home, smart agriculture, smart logistics)
- Consumer electronics (smartphones, tablets, wearable devices)
Q & A
- What are the primary standards that the ADM485JR complies with?
The ADM485JR complies with EIA standards RS-485 and RS-422.
- What is the operating voltage of the ADM485JR?
The ADM485JR operates from a single 5 V power supply.
- What is the maximum data rate supported by the ADM485JR?
The ADM485JR supports data rates up to 5 Mbps.
- What kind of protection does the ADM485JR have against excessive power dissipation?
The ADM485JR features thermal shutdown protection to prevent excessive power dissipation during fault conditions.
- How many transceivers can be connected on a bus using the ADM485JR?
Up to 32 transceivers can be connected simultaneously on a bus.
- What is the propagation delay for the driver and receiver of the ADM485JR?
The driver propagation delay is 10 ns typical, and the receiver propagation delay is 15 ns typical.
- Does the ADM485JR have ESD protection?
Yes, the ADM485JR has ESD protection on all inputs and outputs.
- What is the fail-safe feature of the receiver in the ADM485JR?
The receiver features a fail-safe function that results in a logic high output state if the inputs are unconnected (floating).
- What are some common applications of the ADM485JR?
Common applications include low power RS-485 systems, DTE/DCE interfaces, packet switching, local area networks, and more.
- What package type is the ADM485JR available in?
The ADM485JR is available in an SOIC-8 package.
