Overview
The ADM4851AR from Analog Devices Inc. is a half-duplex RS-485/RS-422 transceiver designed for high-speed data communication on multipoint bus transmission lines. This device is part of the ADM4850 to ADM4857 family, which offers various data rate options and is compliant with EIA Standards RS-485 and RS-422. The ADM4851AR is specifically optimized for a data rate of 500 kbps, making it suitable for applications requiring reliable and efficient data transmission.
Key Specifications
| Parameter | Value | Unit | Comments |
|---|---|---|---|
| Data Rate | 500 kbps | ||
| Propagation Delay (tPLH, tPHL) | 250 - 600 ns | ns | RLDIFF = 54 Ω, CL1 = CL2 = 100 pF |
| Skew (tSKEW) | 40 ns | ns | RLDIFF = 54 Ω, CL1 = CL2 = 100 pF |
| Rise/Fall Times (tR, tF) | 200 - 600 ns | ns | RLDIFF = 54 Ω, CL1 = CL2 = 100 pF |
| Supply Voltage (VCC) | 4.75V - 5.25V | V | |
| Package | 8-lead SOIC, 8-lead LFCSP | ||
| Temperature Range | -40°C to +85°C | °C | |
| Bus Common-Mode Range | -7 V to +12 V | V |
Key Features
- EIA RS-485/RS-422 Compliance: Ensures compatibility with industry standards for data communication.
- Half-Duplex Operation: Shares differential lines with separate enable inputs for the driver and receiver.
- True Fail-Safe Receiver Inputs: Guarantees a logic high output level when the inputs are open or shorted.
- Slew Rate Limited Driver Outputs: Reduces electromagnetic interference (EMI) and data errors caused by reflections from improperly terminated buses.
- Thermal Shutdown and Short-Circuit Protection: Prevents excessive power dissipation caused by bus contention or output shorting.
- Low Power Consumption: Maximum supply current of 5 µA in shutdown mode.
- High Bus Capacity: Allows up to 256 transceivers on one bus.
Applications
- Low Power RS-485 Applications: Ideal for systems where power efficiency is crucial.
- EMI Sensitive Systems: Suitable for environments where electromagnetic interference needs to be minimized.
- DTE to DCE Interfaces: Used in data terminal equipment to data circuit-terminating equipment interfaces.
- Industrial Control: Applied in industrial automation and control systems.
- Packet Switching and Local Area Networks: Used in networking applications requiring reliable data transmission.
- Level Translators: Can be used as level translators in various communication systems.
Q & A
- What is the data rate of the ADM4851AR?
The ADM4851AR has a data rate of 500 kbps.
- Is the ADM4851AR compliant with industry standards?
- What type of operation does the ADM4851AR support?
The ADM4851AR supports half-duplex operation.
- How does the ADM4851AR handle receiver inputs when they are open or shorted?
The ADM4851AR has true fail-safe receiver inputs, ensuring a logic high output level when the inputs are open or shorted.
- What is the supply voltage range for the ADM4851AR?
The supply voltage range for the ADM4851AR is 4.75V to 5.25V.
- What are the available package options for the ADM4851AR?
The ADM4851AR is available in 8-lead SOIC and 8-lead LFCSP packages.
- What is the temperature range for the ADM4851AR?
The ADM4851AR is specified over the temperature range of -40°C to +85°C.
- How many transceivers can be connected on one bus with the ADM4851AR?
Up to 256 transceivers can be connected on one bus with the ADM4851AR.
- Does the ADM4851AR have any protection features?
- What is the maximum supply current in shutdown mode for the ADM4851AR?
The maximum supply current in shutdown mode for the ADM4851AR is 5 µA.
