Overview
The ADM485EARZ-REEL7 is a 5 V, low-power, half-duplex RS-485/RS-422 transceiver produced by Analog Devices Inc. This device is designed for balanced data transmission and complies with Telecommunication Industry Association/Electronics Industries Association (TIA/EIA) standards for RS-485 and RS-422. It operates from a single 5 V power supply and is suitable for high-speed bidirectional data communication on multipoint bus transmission lines. The ADM485EARZ-REEL7 features a differential line driver and a differential line receiver, making it ideal for applications in electrically harsh environments or where cables can be frequently plugged or unplugged.
Key Specifications
| Parameter | Min | Typ | Max | Unit | Test Conditions/Comments |
|---|---|---|---|---|---|
| Input High Voltage (VIH) | 2.0 | V | DE, DI, RE | ||
| Input Low Voltage (VIL) | 0.8 | V | DE, DI, RE | ||
| Logic Input Current (IIN1) | ±2 μA | A | DE, DI, RE | ||
| Driver Propagation Delay (tDPLH, tDPHL) | 10 | 40 | 60 | ns | RDIFF = 54 Ω, CL1 = CL2 = 100 pF |
| Rise/Fall Time (tDR, tDF) | 3 | 20 | 40 | ns | RDIFF = 54 Ω, CL1 = CL2 = 100 pF |
| Enable Time to High Level (tDZH) | 45 | 70 | ns | CL = 100 pF, S1 closed | |
| ESD Protection | ±15 kV | Human Body Model (HBM) | |||
| Power Supply Voltage (VCC) | 4.75 | 5 | 5.25 | V |
Key Features
- TIA/EIA RS-485/RS-422 compliant
- ±15 kV ESD protection on RS-485 I/O pins (Human Body Model)
- Single 5 V power supply operation
- Differential line driver and receiver for balanced data transmission
- Half-duplex operation with shared differential pins for driver and receiver
- Thermal shutdown circuit to prevent excessive power dissipation
- High-Z outputs when power is off
- Available in 8-lead PDIP, 8-lead SOIC, and 8-lead MSOP packages
Applications
- Low power RS-485 systems
- DTE/DCE interfaces
- Packet switching
- Local area networks (LANs)
- Data concentration and data multiplexers
- Integrated services digital network (ISDN)
Q & A
- What is the primary function of the ADM485EARZ-REEL7?
The ADM485EARZ-REEL7 is a half-duplex RS-485/RS-422 transceiver designed for balanced data transmission.
- What are the key standards that the ADM485EARZ-REEL7 complies with?
The device complies with TIA/EIA standards for RS-485 and RS-422.
- What is the operating voltage of the ADM485EARZ-REEL7?
The device operates from a single 5 V power supply.
- What type of ESD protection does the ADM485EARZ-REEL7 offer?
The device offers ±15 kV ESD protection on RS-485 I/O pins (Human Body Model).
- What are the typical applications of the ADM485EARZ-REEL7?
Applications include low power RS-485 systems, DTE/DCE interfaces, packet switching, local area networks (LANs), data concentration, data multiplexers, and integrated services digital network (ISDN).
- What are the available package types for the ADM485EARZ-REEL7?
The device is available in 8-lead PDIP, 8-lead SOIC, and 8-lead MSOP packages.
- How does the thermal shutdown feature work in the ADM485EARZ-REEL7?
The thermal shutdown circuit prevents excessive power dissipation by shutting down the device if a significant temperature increase is detected in the internal driver circuitry.
- What is the maximum data rate supported by the ADM485EARZ-REEL7?
The device supports data rates up to 250 kbps for the ADM487E variant, but specific rates can vary depending on the exact model and configuration.
- Can the driver and receiver of the ADM485EARZ-REEL7 be enabled independently?
Yes, both the driver and the receiver can be enabled independently, and when disabled, the outputs are three-stated.
- What is the input impedance of the ADM485EARZ-REEL7?
The input impedance on the ADM485E is 12 kΩ, allowing up to 32 transceivers on the differential bus.
