Overview
The ADM1485JRZ from Analog Devices is a high-speed, low-power differential line transceiver designed for bidirectional data communication on multipoint bus transmission lines. It complies with both RS-485 and RS-422 EIA standards, making it suitable for a wide range of applications. The device features a differential line driver and a differential line receiver, both of which can be enabled independently. When disabled, the outputs are three-stated, and the driver maintains high output impedance over the entire common-mode voltage range from –7V to +12V. The receiver includes a fail-safe feature that ensures a logic high output state if the inputs are unconnected or floating.
Key Specifications
| Parameter | Value | Unit | Comments |
|---|---|---|---|
| Data Rate | 30 | Mbps | |
| Supply Voltage | 5 | V | Single 5V supply |
| Driver Propagation Delay | 10 | ns | |
| Receiver Propagation Delay | 15 | ns | |
| Operating Temperature Range | 0°C to 70°C | ||
| Package Style | 8-lead SOIC-N | ||
| Common-Mode Voltage Range | –7V to +12V | ||
| Input Resistance | 12 kΩ (minimum) | At –7V ≤ VCM ≤ +12V | |
| Thermal Shutdown Protection | Yes | Disables driver outputs at 150°C, re-enables at 140°C | |
| Short-Circuit Protection | Yes |
Key Features
- Complies with RS-485 and RS-422 EIA standards
- High-speed data rate of 30 Mbps
- Single 5V power supply
- Thermal shutdown protection to prevent excessive power dissipation
- Short-circuit protection
- High-Z outputs when disabled or powered down
- Fail-safe receiver feature ensuring logic high output state if inputs are unconnected
- Low skew to minimize EMI interference
- BiCMOS technology for low power and fast switching speeds
Applications
- Low power RS-485 systems
- DTE-DCE interface
- Packet switching
- Local area networks
- Data concentration
- Data multiplexers
- Integrated services digital network (ISDN)
Q & A
- What are the main standards that the ADM1485JRZ complies with?
The ADM1485JRZ complies with both RS-485 and RS-422 EIA standards.
- What is the maximum data rate of the ADM1485JRZ?
The maximum data rate is 30 Mbps.
- What is the power supply requirement for the ADM1485JRZ?
The device operates from a single 5V power supply.
- What protection features does the ADM1485JRZ have?
The device features thermal shutdown protection and short-circuit protection.
- What happens to the driver outputs when they are disabled or powered down?
The driver outputs are three-stated and maintain high impedance.
- What is the fail-safe feature of the receiver?
The receiver ensures a logic high output state if the inputs are unconnected or floating.
- What is the operating temperature range of the ADM1485JRZ?
The operating temperature range is 0°C to 70°C.
- What is the package style of the ADM1485JRZ?
The package style is 8-lead SOIC-N.
- How does the thermal shutdown protection work?
The thermal shutdown protection disables the driver outputs at 150°C and re-enables them at 140°C.
- What are some common applications of the ADM1485JRZ?
Common applications include low power RS-485 systems, DTE-DCE interface, packet switching, local area networks, data concentration, data multiplexers, and integrated services digital network (ISDN).
