Overview
The ADM487EARZ, produced by Analog Devices Inc., is a 5 V, low-power, half-duplex RS-485/RS-422 transceiver. This device is designed for balanced data transmission and complies with TIA/EIA standards RS-485 and RS-422. It is particularly suited for operation in electrically harsh environments and applications where cables may be frequently plugged or unplugged. The ADM487EARZ features a differential line driver and a differential line receiver, making it ideal for half-duplex data transmission.
Key Specifications
| Specification | Value |
|---|---|
| Supply Voltage | 5 V ± 10% |
| Data Rate | Up to 250 kbps |
| Input Impedance | 48 kΩ (allowing up to 128 transceivers on the differential bus) |
| ESD Protection | ±15 kV Human Body Model (HBM) |
| No Load Supply Current | 120 - 250 μA (RE = 0 V, DE = VCC) |
| Supply Current in Shutdown | 0.5 - 10 μA (DE = 0 V, RE = VCC) |
| Driver Short-Circuit Current | 35 - 250 mA (−7 V ≤ VO ≤ +12 V) |
| Receiver Short-Circuit Current | 7 - 95 mA (0 V ≤ VO ≤ VCC) |
Key Features
- TIA/EIA RS-485 and RS-422 compliant
- ±15 kV ESD protection on RS-485 I/O pins
- Low power consumption with a no-load supply current of 120 - 250 μA
- Thermal shutdown circuit to prevent excessive power dissipation
- Fail-safe receiver output state (logic high if inputs are unconnected)
- Half-duplex operation with shared differential pins for driver and receiver
Applications
- Industrial automation and control systems
- Building automation and control systems
- Remote sensors and data acquisition systems
- Point-of-sale terminals and other commercial equipment
- Any application requiring reliable, high-speed data transmission in electrically harsh environments
Q & A
- What is the primary function of the ADM487EARZ?
The ADM487EARZ is a half-duplex RS-485/RS-422 transceiver designed for balanced data transmission.
- What are the TIA/EIA standards that the ADM487EARZ complies with?
The ADM487EARZ complies with TIA/EIA standards RS-485 and RS-422.
- What is the supply voltage range for the ADM487EARZ?
The supply voltage range is 5 V ± 10%.
- What level of ESD protection does the ADM487EARZ offer?
The ADM487EARZ offers ±15 kV ESD protection according to the Human Body Model (HBM).
- How many transceivers can be connected on the differential bus?
Up to 128 transceivers can be connected on the differential bus due to the 48 kΩ input impedance.
- What is the maximum data rate supported by the ADM487EARZ?
The maximum data rate supported is up to 250 kbps.
- Does the ADM487EARZ have thermal protection?
Yes, the ADM487EARZ features a thermal shutdown circuit to prevent excessive power dissipation.
- What happens to the receiver output if the inputs are unconnected?
The receiver output defaults to a logic high state if the inputs are unconnected (floating).
- What is the typical application environment for the ADM487EARZ?
The ADM487EARZ is suited for operation in electrically harsh environments and applications where cables may be frequently plugged or unplugged.
- What is the package type of the ADM487EARZ?
The ADM487EARZ is available in an 8-lead SOIC package.
