Overview
The ST485CDR is a low-power RS-485/RS-422 transceiver produced by STMicroelectronics. This component is designed for bi-directional data communications on multipoint bus transmission lines, particularly in half-duplex applications. It contains one driver and one receiver, making it suitable for a variety of communication protocols. The ST485CDR operates from a single 5 V supply and is characterized by its low quiescent current of 300 μA, which is beneficial for power-sensitive applications.
Key Specifications
| Parameter | Value | Unit |
|---|---|---|
| Supply Voltage (VCC) | 5 | V |
| Supply Current (ICC) | 300 | μA |
| Propagation Delay (tPLH, tPHL) | 10 - 70 | ns |
| Differential Driver Output (VOD1, VOD2) | 1.4 - 5 | V |
| Common Mode Input Voltage Range | -7 to 12 | V |
| Receiver Differential Threshold Voltage (VTH) | -0.2 to 0.2 | V |
| Receiver Input Hysteresis (∆VTH) | 70 | mV |
| Maximum Data Rate (fMAX) | 2.5 | Mbps |
| Operating Temperature Range | 0 to 70 °C (commercial), -40 to 85 °C (industrial), -55 to 125 °C (automotive) | °C |
| Package Type | SO-8 (Tube and Reel) |
Key Features
- Operates from a single 5 V supply.
- Low quiescent current: 300 μA.
- 30 ns propagation delay, 5 ns skew.
- Allows up to 64 transceivers on the bus.
- -7 V to 12 V common mode input voltage range.
- Designed for RS-485 interface applications.
- 70 mV typical input hysteresis.
- Current limiting and thermal shutdown for driver overload protection.
- Driver maintains high impedance in 3-state or with the power OFF.
Applications
The ST485CDR is suitable for various applications requiring RS-485 and RS-422 communication, including:
- Industrial automation and control systems.
- Building automation and control systems.
- Automotive systems requiring robust communication interfaces.
- Point-of-sale terminals and other commercial equipment.
- Multipoint bus transmission lines in half-duplex configurations.
Q & A
- What is the typical supply current of the ST485CDR?
The typical supply current is 300 μA when unloaded or fully loaded with disabled drivers.
- What is the operating voltage range of the ST485CDR?
The ST485CDR operates from a single 5 V supply.
- What is the maximum data rate supported by the ST485CDR?
The maximum data rate is 2.5 Mbps.
- How many transceivers can be connected on the same bus?
Up to 64 transceivers can be connected on the same bus.
- What is the common mode input voltage range of the ST485CDR?
The common mode input voltage range is -7 V to 12 V.
- Does the ST485CDR have built-in protection features?
Yes, it has current limiting and thermal shutdown for driver overload protection.
- What are the available temperature ranges for the ST485CDR?
The available temperature ranges are commercial (0 °C to 70 °C), industrial (-40 °C to 85 °C), and automotive (-55 °C to 125 °C).
- What is the package type of the ST485CDR?
The package type is SO-8, available in tube and reel.
- What is the propagation delay of the ST485CDR?
The propagation delay is 30 ns with a skew of 5 ns.
- Is the ST485CDR suitable for half-duplex applications?
Yes, it is designed for bi-directional data communications on multipoint bus transmission lines in half-duplex applications.
