CA-IS3417
Isolated RS-485 transceiver with 5kVrms isolation, 20Mbps data rate, and comprehensive bus protection for
Product Overview
Description
CA-IS3417 is a high-performance isolated RS-485 transceiver featuring reinforced isolation rated at 5kVrms. The device combines a digital isolator with a robust RS-485 transceiver in a single package.
With data rates up to 20Mbps and comprehensive bus protection, this transceiver is ideal for industrial automation, building control, and motor drive applications.
The device includes fail-safe features, thermal protection, and ESD protection for reliable operation in harsh environments.
Product Series
CA
Primary Application
Industrial automation
Key Features
- 5kVrms reinforced isolation
- High speed up to 20Mbps
- ±16kV ESD protection
- ±58V fault protection
- Fail-safe receiver inputs
- Current limiting and thermal protection
- Open-circuit, short-circuit fail-safe
- Low power shutdown mode
Specifications
| Protocol | RS-485/RS-422 |
|---|---|
| Isolation Voltage | 5kVrms (reinforced) |
| Data Rate | Up to 20Mbps |
| Bus Protection | ±16kV ESD, ±58V fault |
| Nodes on Bus | Up to 256 |
| Supply Voltage | 3.3V or 5V (logic side) |
| Isolated Supply | 3.3V or 5V |
| Package | SOIC-16, QSOP-16 |
Applications
Industrial automation
Industrial automation and control
Building control systems
Industrial automation and control
Motor drives
Motor drive and control systems
Power monitoring
Electronic system design
HVAC systems
Electronic system design
Security systems
Electronic system design
Process control
Industrial automation and control
FAE Expert Insights
"CA-IS3417 is an excellent isolated RS-485 solution for industrial networks. The integration of isolation and transceiver in one package saves significant board space compared to discrete solutions. I've used this part in building automation systems with long bus runs and multiple nodes. The high CMTI ensures reliable communication even with motor drives on the same power system. The comprehensive protection features prevent damage from wiring faults and transients. For best EMC performance, I recommend proper termination at both bus ends and using shielded twisted pair cable."
Integrated isolated RS-485 with comprehensive protection
— Dr. Chen Wei, BeiLuo
Frequently Asked Questions
What is the maximum bus length for CA-IS3417?
CA-IS3417 supports RS-485 bus lengths up to 1200 meters (4000 feet) at lower data rates. Maximum length vs data rate: 1200m at 100kbps; 600m at 1Mbps; 150m at 10Mbps; 50m at 20Mbps. These are typical values - actual maximum depends on cable quality, termination, and noise environment. Use shielded twisted pair cable (120Ω characteristic impedance) for best performance. Terminate the bus at both ends with 120Ω resistors. For long buses, use proper grounding to avoid ground loops.
Follow RS-485 length guidelines based on data rate. Contact our FAE team for network design.
How many nodes can be connected to a CA-IS3417 network?
CA-IS3417 supports up to 256 nodes on a single RS-485 bus. This is determined by the unit load of each transceiver. Standard RS-485 allows 32 unit loads (32 standard transceivers). CA-IS3417 is 1/8 unit load, allowing 8× more nodes (256). For networks with mixed transceivers: Calculate total unit loads (1 unit load per standard, 1/8 per CA-IS3417); Keep total ≤ 32 unit loads; and Use repeaters for larger networks. In practice, 256 nodes is the theoretical maximum - practical limits may be lower due to cable capacitance and power dissipation.
Up to 256 CA-IS3417 nodes per bus. Contact our FAE team for large network design.
What is the fail-safe feature in CA-IS3417?
CA-IS3417 includes multiple fail-safe features: Open-circuit fail-safe: Receiver outputs high (inactive) if bus is open; Short-circuit fail-safe: Receiver outputs high if bus is shorted; Idle-bus fail-safe: Receiver outputs high if no driver is active; and Full fail-safe: No external bias resistors needed. These features ensure the receiver is in a known state (logic high) during fault conditions, preventing false triggering. Traditional RS-485 requires external bias resistors for fail-safe operation. CA-IS3417's integrated fail-safe simplifies design and improves reliability.
Fail-safe is automatic, no external components needed. Contact our FAE team for fail-safe operation details.
How do I terminate an RS-485 bus with CA-IS3417?
Proper RS-485 termination is essential for reliable communication: Place 120Ω termination resistors at both ends of the bus only; Do not place termination at intermediate nodes; Use resistors matching cable characteristic impedance (typically 120Ω); For long buses, use termination at both ends; For short buses (<100m at low speed), termination may be optional. CA-IS3417 has high input impedance (1/8 unit load), so termination current is minimal. Biasing resistors are not needed due to integrated fail-safe. Proper termination prevents signal reflections that cause data errors.
Use 120Ω termination at both bus ends. Contact our FAE team for termination guidelines.
Can CA-IS3417 be used in multi-master RS-485 networks?
Yes, CA-IS3417 supports multi-master (peer-to-peer) RS-485 networks where any node can initiate communication. For multi-master operation: Use RS-485 transceivers with driver enable control; Implement collision detection in software; Use appropriate protocol (Modbus RTU, custom protocol); and Handle bus arbitration. CA-IS3417 has separate driver enable (DE) and receiver enable (RE) pins for flexible control. The high CMTI ensures reliable operation even when multiple drivers switch simultaneously during collisions.
CA-IS3417 supports multi-master with proper protocol. Contact our FAE team for multi-master design.
What cable should I use for RS-485 with CA-IS3417?
Recommended cable for RS-485 with CA-IS3417: Type: Shielded twisted pair (STP); Characteristic impedance: 120Ω (matches termination); Wire gauge: 24-26 AWG for typical distances; Shield: Overall foil or braid shield; Twist rate: Regular twisting for noise rejection. Recommended cables: Belden 3109A, 9841; Alpha Wire 5413; or equivalent industrial RS-485 cable. For long distances or high noise environments, use cable with higher shield coverage. Avoid running RS-485 cables parallel to high-voltage power cables.
Use 120Ω STP cable for best performance. Contact our FAE team for cable recommendations.