CA-IS3760
Quad channel digital isolator with integrated isolated DC-DC converter, providing complete isolated signal
Product Overview
Description
CA-IS3760 is a quad channel digital isolator featuring an integrated isolated DC-DC converter, providing both signal isolation and isolated power in a single chip solution.
The device eliminates the need for external isolated power supplies, reducing BOM cost and board space. The integrated DC-DC provides up to 150mW of isolated power.
With 5kVrms reinforced isolation and 150Mbps data rate, CA-IS3760 is ideal for space-constrained applications requiring complete isolation solutions.
Product Series
CA
Primary Application
Isolated sensor interfaces
Key Features
- Integrated isolated DC-DC converter
- Complete isolation solution in one chip
- 5kVrms reinforced isolation
- 150Mbps data rate
- Up to 150mW isolated power output
- No external isolated supply needed
- Soft-start and overload protection
- Thermal shutdown protection
Specifications
| Channels | 4 (all same direction) |
|---|---|
| Isolation Voltage | 5kVrms (reinforced) |
| Data Rate | Up to 150Mbps |
| Isolated Output Power | Up to 150mW |
| Efficiency | Up to 50% |
| Propagation Delay | 15ns typical |
| Supply Voltage | 3.3V or 5V input |
| Package | SOIC-20, SSOP-20 |
Applications
Isolated sensor interfaces
Sensor signal conditioning
Industrial I/O modules
Industrial automation and control
Isolated ADC/DAC interfaces
Communication and interface
Power supply feedback
Power conversion and supply
Communication interfaces
Communication and interface
Medical equipment
Medical electronics
Test and measurement
Data acquisition and conversion
FAE Expert Insights
"CA-IS3760 is an excellent solution for applications requiring both signal and power isolation. The integrated DC-DC converter saves significant board space and BOM cost compared to separate signal isolator + isolated DC-DC solutions. I've used this part in isolated sensor interfaces where the 150mW output power is sufficient to drive the sensor and ADC on the isolated side. The efficiency is good (around 50%), and the soft-start feature prevents inrush current issues. For best performance, follow the recommended PCB layout for the DC-DC section, paying attention to the transformer isolation barrier area. The single-chip solution also simplifies EMC compliance."
Complete isolation solution with integrated DC-DC converter
— Dr. Chen Wei, BeiLuo
Frequently Asked Questions
How much power can the integrated DC-DC provide?
CA-IS3760's integrated DC-DC converter can provide up to 150mW of isolated output power. This is sufficient for: Powering isolated sensors (typically 10-50mW); Driving isolated ADCs (20-40mW); Powering small microcontrollers on isolated side (50-100mW); and Driving isolated communication transceivers (30-60mW). The actual available power depends on input voltage and ambient temperature. At 5V input and 25°C, you can expect 130-150mW. At 3.3V input or high temperature, available power is reduced to 100-120mW. Calculate your isolated side power budget carefully.
Calculate isolated side power requirements. Contact our FAE team for power budget analysis.
What external components are needed for the DC-DC converter?
CA-IS3760 requires minimal external components for the DC-DC converter: Input capacitor (4.7μF ceramic) on VCC pin; Output capacitor (4.7μF ceramic) on VISO pin; and Optional soft-start capacitor (10nF) if slower startup is desired. No external inductors or transformers are needed as these are integrated. The total external component count is much lower than discrete DC-DC solutions. Place capacitors close to the respective pins with short traces. Use X5R or X7R ceramic capacitors with adequate voltage rating (10V or higher).
Use recommended capacitor values close to pins. Contact our FAE team for layout recommendations.
Can I use CA-IS3760 for isolated RS-485 interface?
Yes, CA-IS3760 can be combined with a standard RS-485 transceiver to create an isolated RS-485 interface. The isolated power from CA-IS3760 can power the RS-485 transceiver on the isolated side. Typical power consumption: Isolated RS-485 transceiver (30-50mW); CA-IS3760 signal channels (negligible); Total: well within 150mW budget. Connect CA-IS3760 channels to RS-485 transceiver control and data pins. This approach is more flexible than integrated isolated RS-485 transceivers and allows you to choose the exact RS-485 features needed.
Use CA-IS3760 + standard RS-485 for flexible isolated interface. Contact our FAE team for reference designs.
What is the efficiency of the integrated DC-DC converter?
CA-IS3760's integrated DC-DC converter achieves typical efficiency of 45-50% depending on load and input voltage. At full load (150mW output) with 5V input, efficiency is approximately 47-50%. At lighter loads, efficiency decreases slightly due to quiescent power consumption. The efficiency is comparable to or better than other integrated isolated DC-DC solutions. For higher efficiency requirements, consider using CA-IS3740 (without DC-DC) with an external high-efficiency isolated DC-DC module. The integrated solution trades some efficiency for convenience and space savings.
For highest efficiency, use external DC-DC. For space savings, accept CA-IS3760 efficiency. Contact our FAE team for efficiency optimization.
How do I calculate thermal performance of CA-IS3760?
CA-IS3760 thermal performance depends on power dissipation and package thermal resistance. Power dissipation = Input Power - Output Power. At 150mW output with 50% efficiency, input power is 300mW, so dissipation is 150mW. SOIC-20 thermal resistance is approximately 80°C/W. Temperature rise = 150mW × 80°C/W = 12°C. Junction temperature at 25°C ambient = 25 + 12 = 37°C, well below 125°C maximum. At 85°C ambient, junction temperature = 85 + 12 = 97°C, still within safe operating area. For high ambient temperatures or continuous operation, ensure adequate PCB copper area for heat dissipation.
Calculate thermal performance for your operating conditions. Contact our FAE team for thermal analysis.
What protection features does the DC-DC converter have?
CA-IS3760's integrated DC-DC converter includes comprehensive protection features: Soft-start to limit inrush current during power-up; Over-current protection (OCP) to prevent damage from overloads; Short-circuit protection with automatic recovery; Over-temperature protection (OTP) with thermal shutdown at 150°C; and Under-voltage lockout (UVLO) to prevent operation at low input voltage. These protections ensure reliable operation and prevent damage to the device and system under fault conditions. The protection features are automatic and require no external components or configuration.
Built-in protections ensure reliable operation. Contact our FAE team for protection feature details.