Overview
The ADM2485BRWZ, produced by Analog Devices Inc., is an integrated, galvanically isolated differential bus transceiver designed for bidirectional data communication on multipoint bus transmission lines. This component combines a 3-channel isolator, a three-state differential line driver, and a differential input receiver into a single package, utilizing Analog Devices' iCoupler® technology. It is compliant with ANSI/TIA/EIA RS-485-A-98 and ISO 8482:1987(E) standards, making it suitable for balanced transmission lines. The device supports both 3.3 V and 5 V logic side power supplies and an isolated 5 V bus side power supply, with built-in features such as current-limiting and thermal shutdown for protection against output short circuits and excessive power dissipation.
Key Specifications
| Parameter | Min | Typ | Max | Unit | Test Conditions/Comments |
|---|---|---|---|---|---|
| VDD1 | 2.7 | - | 5.5 | V | TMIN to TMAX, unless otherwise noted |
| VDD2 | 4.75 | - | 5.25 | V | TMIN to TMAX, unless otherwise noted |
| Differential Output Voltage (VOD) | 2.1 | - | 5 | V | R = 27 Ω or 50 Ω |
| Rated Dielectric Insulation Voltage | - | - | 2500 | V rms | 1-minute duration |
| Minimum External Air Gap (External Clearance) | - | - | 5.15 | mm | Measured from input terminals to output terminals, shortest distance through air |
| Minimum External Tracking (Creepage) | - | - | 5.5 | mm | Measured from input terminals to output terminals, shortest distance along body |
| Minimum Internal Gap (Internal Clearance) | - | - | 0.017 | mm | Insulation distance through insulation |
Key Features
- Galvanic isolation using iCoupler® technology, providing 3-channel isolation, a three-state differential line driver, and a differential input receiver in one package.
- Compliance with ANSI/TIA/EIA RS-485-A-98 and ISO 8482:1987(E) standards for balanced transmission lines.
- Support for both 3.3 V and 5 V logic side power supplies and an isolated 5 V bus side power supply.
- Active high enable for the driver and active high receiver disable, allowing the receive output to enter a high impedance state.
- Current-limiting and thermal shutdown features for protection against output short circuits and excessive power dissipation.
- Full specification over the industrial temperature range and availability in a 16-lead, wide-body SOIC package.
Applications
The ADM2485BRWZ is suitable for various applications requiring reliable, isolated bidirectional data communication. These include industrial control systems, medical devices, automotive systems, and any environment where galvanic isolation is necessary to protect against electrical noise and ground loops. It is particularly useful in multipoint bus transmission lines where balanced transmission is required.
Q & A
- What is the primary function of the ADM2485BRWZ?
The ADM2485BRWZ is a differential bus transceiver designed for bidirectional data communication on multipoint bus transmission lines, providing galvanic isolation. - What standards does the ADM2485BRWZ comply with?
The device complies with ANSI/TIA/EIA RS-485-A-98 and ISO 8482:1987(E) standards. - What are the supported power supply voltages for the logic and bus sides?
The logic side can be powered with either 3.3 V or 5 V, and the bus side is powered with an isolated 5 V supply. - What protection features does the ADM2485BRWZ have?
The device includes current-limiting and thermal shutdown features to protect against output short circuits and excessive power dissipation. - What is the significance of the iCoupler® technology in the ADM2485BRWZ?
The iCoupler® technology provides galvanic isolation, combining a 3-channel isolator, a three-state differential line driver, and a differential input receiver into a single package. - What is the typical package type for the ADM2485BRWZ?
The device is available in a 16-lead, wide-body SOIC package. - What are some common applications for the ADM2485BRWZ?
Common applications include industrial control systems, medical devices, automotive systems, and any environment requiring isolated bidirectional data communication. - How does the ADM2485BRWZ handle receiver disable?
The device has an active high receiver disable that causes the receive output to enter a high impedance state. - What is the rated dielectric insulation voltage for the ADM2485BRWZ?
The rated dielectric insulation voltage is 2500 V rms for a 1-minute duration. - What is the minimum external air gap and creepage distance for the ADM2485BRWZ?
The minimum external air gap is 5.15 mm, and the minimum external tracking (creepage) is 5.5 mm.
