Overview
The ADM4856ARZ-REEL7 from Analog Devices Inc. is a high-performance, single transmitter/receiver RS-422/RS-485 transceiver. This device is designed for high-speed, half-duplex and full-duplex data communication on multipoint bus transmission lines. It is part of the ADM4850 to ADM4857 family, which offers various data rate options to suit different application requirements.
The ADM4856 specifically supports a data rate of 2.5 Mbps, making it suitable for applications that require reliable and fast data transmission. The device is available in an 8-lead SOIC package and is pin-compatible with the MAX308x series, offering flexibility in design and integration.
Key Specifications
| Parameter | Symbol | Min | Typ | Max | Unit | Test Conditions/Comments |
|---|---|---|---|---|---|---|
| Maximum Data Rate | - | - | - | 2.5 Mbps | - | |
| Propagation Delay | tPLH, tPHL | 50 | - | 180 ns | RLDIFF = 54 Ω, CL1 = CL2 = 100 pF | |
| Skew | tSKEW | 50 | - | - | ns | RLDIFF = 54 Ω, CL1 = CL2 = 100 pF |
| Rise/Fall Times | tR, tF | 140 | - | - | ns | RLDIFF = 54 Ω, CL1 = CL2 = 100 pF |
| Disable Time | tLZ, tHZ | 20 | - | 50 ns | RL = 1 kΩ, CL = 15 pF | |
| Enable Time from Shutdown | - | - | - | 4000 ns | RL = 1 kΩ, CL = 15 pF | |
| Supply Current in Shutdown Mode | - | - | - | 5 µA | - | |
| Bus Common-Mode Range | - | -7 V | - | +12 V | - | |
| Operating Temperature Range | - | -40°C | - | +85°C | - |
Key Features
- RS-485/RS-422 Compliance: The ADM4856 is compliant with EIA RS-485 and RS-422 standards, ensuring compatibility with a wide range of applications.
- High-Speed Data Transmission: Supports data rates up to 2.5 Mbps, making it suitable for high-speed data communication.
- Half-Duplex and Full-Duplex Options: Offers flexibility in communication modes to suit different application needs.
- Reduced Slew Rates: Helps in minimizing electromagnetic interference (EMI).
- True Fail-Safe Receiver Inputs: Ensures a logic high output level when the inputs are open or shorted, providing a known state before and after communication.
- Thermal Shutdown and Short-Circuit Protection: Provides robust protection against thermal and short-circuit conditions.
- Low Power Consumption: 5 µA maximum supply current in shutdown mode, which is energy-efficient.
- Multi-Transceiver Capability: Allows up to 256 transceivers on one bus due to its 1/8-unit load receiver input impedance.
Applications
- Industrial Automation: Suitable for use in industrial control systems and automation where reliable and fast data transmission is critical.
- Building Automation: Can be used in building management systems for controlling and monitoring various parameters.
- Medical Devices: Applicable in medical equipment where high-speed and reliable data communication is essential.
- Automotive Systems: Used in automotive networks for communication between different components of the vehicle.
- Telecommunications: Can be employed in telecommunications equipment for reliable data transmission over long distances.
Q & A
- What is the maximum data rate supported by the ADM4856?
The ADM4856 supports a maximum data rate of 2.5 Mbps.
- What are the operating temperature ranges for the ADM4856?
The operating temperature range for the ADM4856 is from -40°C to +85°C.
- Is the ADM4856 compliant with RS-485 and RS-422 standards?
Yes, the ADM4856 is compliant with EIA RS-485 and RS-422 standards.
- What is the maximum number of transceivers that can be connected on one bus?
Up to 256 transceivers can be connected on one bus due to the 1/8-unit load receiver input impedance.
- Does the ADM4856 have thermal shutdown and short-circuit protection?
Yes, the ADM4856 includes thermal shutdown and short-circuit protection features.
- What is the supply current in shutdown mode for the ADM4856?
The supply current in shutdown mode is 5 µA maximum.
- What package types are available for the ADM4856?
The ADM4856 is available in an 8-lead SOIC package.
- Does the ADM4856 support half-duplex and full-duplex communication modes?
Yes, the ADM4856 supports both half-duplex and full-duplex communication modes.
- What is the bus common-mode range for the ADM4856?
The bus common-mode range for the ADM4856 is from -7 V to +12 V.
- Are the receiver inputs of the ADM4856 fail-safe?
Yes, the receiver inputs of the ADM4856 have a true fail-safe feature, ensuring a logic high output level when the inputs are open or shorted.
