XB-48501
Robust RS-485/RS-422 transceiver with high ESD protection and wide common-mode range for industrial applications.
Product Overview
Description
The XB-48501 is a robust RS-485/RS-422 transceiver designed for demanding industrial environments.
It features high ESD protection and wide common-mode voltage range for reliable communication.
The half-duplex operation and low power consumption make it ideal for multi-node networks.
Product Series
XB
Primary Application
Industrial automation networks
Key Features
- High ESD protection ±15kV
- Wide common-mode range -7V to +12V
- 3.3V and 5V supply compatible
- Up to 256 nodes on bus
- Half-duplex operation
- Fail-safe receiver design
- Thermal shutdown protection
- Low power consumption
Specifications
| Protocol | RS-485/RS-422 |
|---|---|
| Data Rate | Up to 500kbps |
| ESD Protection | ±15kV IEC 61000-4-2 |
| Common Mode Range | -7V to +12V |
| Supply Voltage | 3.3V or 5V |
| Nodes on Bus | Up to 256 |
| Quiescent Current | 1mA typical |
| Package | SOIC-8 |
Applications
Industrial automation networks
Industrial automation and control
Building automation systems
Industrial automation and control
Motor control systems
Motor drive and control systems
Security and surveillance
Electronic system design
Point-of-sale equipment
Electronic system design
FAE Expert Insights
"The XB-48501 is a reliable workhorse for industrial RS-485 networks. The ±15kV ESD protection handles harsh factory environments without external protection components. I particularly appreciate the wide common-mode range which maintains communication even with significant ground potential differences between nodes. The fail-safe receiver ensures defined output when lines are idle or open - no false triggers. For industrial automation, building control, or any multi-node RS-485 application, this transceiver delivers robust performance at a competitive price."
±15kV ESD with wide common-mode range
— Robert Wang, BeiLuo
Frequently Asked Questions
Can XB-48501 operate on 3.3V supply?
Yes, XB-48501 supports both 3.3V and 5V supply voltages. The logic I/O levels match the supply voltage, making it compatible with 3.3V or 5V microcontrollers. The differential output levels meet RS-485 specifications regardless of supply voltage. This dual-voltage support simplifies mixed-voltage system design and allows use with modern 3.3V microcontrollers without level shifting.
XB-48501 works with 3.3V or 5V systems. Select supply based on MCU voltage.
How many devices can be connected to an RS-485 bus?
RS-485 supports up to 32 unit loads on a single bus. The XB-48501 is a 1/8 unit load device, allowing up to 256 devices on the same bus. This high node count is achieved through high-impedance receiver inputs that draw minimal current from the bus. For maximum node count, ensure all devices are fractional unit load. Standard (1 unit load) devices limit the bus to 32 nodes. Plan your network topology and node count accordingly.
XB-48501 supports up to 256 nodes. Check unit load ratings for mixed networks.
What cable should I use for RS-485 networks?
Use twisted-pair cable for RS-485 to maximize noise immunity. Shielded twisted pair (STP) provides best performance in noisy environments. Characteristic impedance should be 120Ω to match termination resistors. Common choices include CAT5/CAT6 Ethernet cable (100Ω) or dedicated RS-485 cable (120Ω). For long distances or high speeds, use cable with lower capacitance. Avoid running RS-485 cables parallel to high-voltage power cables. Use proper grounding practices for shielded cables.
Use 120Ω twisted pair cable. Shield for noisy environments.
Does XB-48501 require external ESD protection?
No, XB-48501 includes integrated ±15kV ESD protection (IEC 61000-4-2) on bus pins, sufficient for most industrial applications. The integrated protection eliminates need for external TVS diodes in typical environments. For extremely harsh environments with frequent severe transients, additional external protection may be considered. The integrated protection saves PCB space and BOM cost while providing reliable ESD immunity.
Integrated protection sufficient for most applications. No external components needed.
What is fail-safe operation in RS-485?
Fail-safe ensures the receiver output is in a defined state (typically high) when the bus is idle, open, or shorted. Without fail-safe, noise on an idle bus can cause random output transitions. XB-48501 includes internal fail-safe biasing that eliminates need for external bias resistors in most applications. The receiver thresholds are offset to ensure logic high output when differential voltage is zero or slightly negative. This simplifies network design and improves reliability.
XB-48501 internal fail-safe eliminates external bias resistors. Receiver output defined for all bus conditions.