CA-IS3740
High-performance quad channel digital isolator with 5kVrms isolation, 150Mbps data rate, and >100kV/μs CMTI
Product Overview
Description
CA-IS3740 is a high-performance quad channel digital isolator featuring reinforced isolation rated at 5kVrms. The device provides four independent isolation channels with data rates up to 150Mbps.
With excellent CMTI performance exceeding 100kV/μs, this isolator ensures reliable operation in noisy industrial environments with fast switching transients.
The device operates from 2.5V to 5.5V supplies on both sides, supporting level translation between different voltage domains. Low propagation delay (13ns typical) makes it ideal for high-speed SPI and parallel interfaces.
Product Series
CA
Primary Application
Industrial automation and control
Key Features
- Reinforced isolation rated at 5kVrms
- High data rate up to 150Mbps
- Excellent CMTI >100kV/μs
- Low propagation delay 13ns typical
- Wide supply range 2.5V to 5.5V
- Auto-direction sensing on some channels
- Robust ESD protection >8kV HBM
- AEC-Q100 qualified (automotive grade)
Specifications
| Channels | 4 (all same direction) |
|---|---|
| Isolation Voltage | 5kVrms (reinforced) |
| Data Rate | Up to 150Mbps |
| CMTI | >100kV/μs (typical) |
| Propagation Delay | 13ns typical |
| Supply Voltage | 2.5V to 5.5V (both sides) |
| Operating Temperature | -40°C to +125°C |
| Package | SOIC-16, QSOP-16 |
Applications
Industrial automation and control
Industrial automation and control
Motor drive interfaces
Motor drive and control systems
Power supply feedback
Power conversion and supply
SPI and I2C isolation
Electronic system design
Medical equipment
Medical electronics
Communication systems
Communication and interface
Automotive electronics
Automotive and EV electronics
FAE Expert Insights
"CA-IS3740 is my top recommendation for quad-channel isolation applications. The 5kVrms reinforced isolation provides excellent safety margins for industrial and medical applications. I've successfully used this part in numerous motor drive designs where the high CMTI performance is critical during IGBT switching. The 150Mbps data rate handles high-speed SPI communication without issues. The pin-compatibility with ISO7740 makes it an easy drop-in replacement with significant cost savings. For best performance, I recommend placing 0.1μF decoupling capacitors close to both VCC pins and keeping high-speed traces short and matched."
5kVrms reinforced isolation with >100kV/μs CMTI performance
— Dr. Chen Wei, BeiLuo
Frequently Asked Questions
What is the difference between CA-IS3740 and CA-IS3741?
CA-IS3740 has all four channels in the same direction (input to output), making it ideal for unidirectional buses like SPI MOSI. CA-IS3741 has three forward channels and one reverse channel, making it suitable for SPI with MISO return or RS-485 with direction control. Both offer the same isolation rating (5kVrms) and data rate (150Mbps). The choice depends on your communication interface requirements. For full-duplex SPI, use CA-IS3740 for MOSI and CA-IS3741 for MISO. For half-duplex or control signals, CA-IS3741 provides flexibility.
Use CA-IS3740 for unidirectional buses. Use CA-IS3741 for bidirectional or mixed-direction interfaces. Contact our FAE team for interface-specific recommendations.
Can CA-IS3740 be used for SPI communication at 50MHz?
Yes, CA-IS3740 is well-suited for 50MHz SPI communication. At 50MHz, the clock period is 20ns. CA-IS3740's typical propagation delay is 13ns, leaving 7ns timing margin. The maximum propagation delay of 20ns still provides adequate margin for most SPI implementations. For reliable operation at 50MHz: Keep PCB traces short (<2 inches); Use proper impedance matching; Place decoupling capacitors close to VCC pins; and Ensure clean power supplies. Many customers successfully use CA-IS3740 for high-speed SPI in industrial and automotive applications.
CA-IS3740 supports 50MHz SPI with proper layout. Contact our FAE team for high-speed SPI design guidelines.
How do I interface CA-IS3740 with 3.3V and 5V systems?
CA-IS3740 supports level translation between different voltage domains. The input side (VCC1) can operate at 2.5V to 5.5V, and the output side (VCC2) can operate independently at 2.5V to 5.5V. For 3.3V to 5V translation: Connect VCC1 to 3.3V and VCC2 to 5V. For 5V to 3.3V translation: Connect VCC1 to 5V and VCC2 to 3.3V. The logic thresholds automatically adjust to the supply voltage on each side. This makes CA-IS3740 ideal for interfacing between different voltage domains in mixed-voltage systems.
Connect VCC1 and VCC2 to respective supply voltages. Contact our FAE team for mixed-voltage interface design.
What is the isolation barrier lifetime of CA-IS3740?
CA-IS3740 uses capacitive isolation technology with an expected isolation barrier lifetime exceeding 60 years at rated working voltage. The isolation barrier is manufactured using standard CMOS processes with silicon dioxide (SiO2) as the dielectric material. SiO2 has excellent long-term reliability and does not degrade significantly over time. The device is qualified to VDE 0884-11 standard which includes accelerated lifetime testing. For applications requiring long service life, CA-IS3740 provides reliable isolation that exceeds the expected lifetime of most electronic systems.
CA-IS3740 provides >60 year isolation lifetime. Contact our FAE team for reliability data and qualification reports.
Does CA-IS3740 support hot-swap applications?
Yes, CA-IS3740 supports hot-swap applications where the device may be inserted or removed while power is applied. The device features: Glitch-free power-up initialization; Robust ESD protection (>8kV HBM) on all pins; No latch-up issues during hot-swap; and Defined output state during power transitions. For hot-swap applications, I recommend: Using series resistors (22-47Ω) on I/O lines to limit inrush current; Implementing soft-start circuits for power supplies; and Following proper hot-swap sequence (ground first, power last). CA-IS3740 has been successfully used in hot-swap applications such as industrial I/O modules and communication interfaces.
CA-IS3740 supports hot-swap with proper circuit design. Contact our FAE team for hot-swap application guidelines.
What are the EMC considerations for using CA-IS3740?
CA-IS3740 has excellent EMC performance with >100kV/μs CMTI rating. For optimal EMC in your system: Use proper PCB layout with short traces and ground planes; Add common mode chokes on I/O lines for high-noise environments; Implement RC snubbers (100Ω + 100pF) on outputs if needed; Keep the isolation barrier area clear of copper; Use shielded cables for external connections; and Follow good grounding practices. CA-IS3740 meets IEC 61000-4-x EMC standards for industrial applications. The high CMTI ensures reliable operation even during fast switching transients from nearby power electronics.
Follow EMC design guidelines for your application. Contact our FAE team for EMC troubleshooting support.