Overview
The ISO1540D, produced by Texas Instruments, is a low-power, bidirectional isolator designed to be compatible with I2C interfaces. This device utilizes Texas Instruments' Capacitive Isolation technology, which employs a silicon dioxide (SiO2) barrier to separate the logic input and output buffers. This technology provides advantages in function, performance, size, and power consumption compared to traditional optocouplers. The ISO1540D is particularly suited for applications requiring isolated I2C communication, ensuring high voltage isolation, ground isolation, and protection against noise currents that could interfere with or damage sensitive circuitry.
Key Specifications
| Parameter | Value | Unit |
|---|---|---|
| Package | SOIC (D) | - |
| Pins | 8 | - |
| Operating Temperature Range | -40 to 125 | °C |
| Supply Voltage Range | 3 to 5.5 | V |
| Operating Frequency | Up to 1 MHz | - |
| Output Current (Side 1) | 0.5 to 3.5 mA | mA |
| Output Current (Side 2) | 0.5 to 35 mA | mA |
| Transient Immunity | ±50 kV/µs (Typical) | kV/µs |
| HBM ESD Protection | 4 kV on all pins; 8 kV on bus pins | kV |
| Isolation Voltage | 4242 VPK (DIN EN IEC 60747-17), 2500 VRMS (UL 1577) | V |
Key Features
- Isolated bidirectional, I2C compatible communication
- Supports up to 1-MHz operation
- 3-V to 5.5-V supply range
- Open-drain outputs with 3.5-mA Side 1 and 35-mA Side 2 sink current capability
- –40°C to +125°C operating temperature range
- ±50-kV/µs transient immunity (Typical)
- HBM ESD protection of 4 kV on all pins; 8 kV on bus pins
- Safety-related certifications: 4242-V Pk isolation per DIN EN IEC 60747-17, 2500-V RMS isolation for 1 minute per UL 1577, CSA approval per IEC 62368-1, and CQC basic insulation per GB4943.1-2011.
Applications
- Isolated I2C buses
- SMBus and PMBus interfaces
- Open-drain networks
- Motor control systems
- Battery management systems
- I2C level shifting
- Multi-controller applications where clock stretching by the target is possible.
Q & A
- What is the primary function of the ISO1540D?
The ISO1540D is a low-power, bidirectional isolator designed for isolated I2C communication, providing high voltage isolation and protection against noise currents.
- What is the operating temperature range of the ISO1540D?
The operating temperature range is –40°C to +125°C.
- What is the maximum operating frequency of the ISO1540D?
The device supports up to 1-MHz operation.
- What are the output current capabilities of the ISO1540D?
The output current capabilities are 0.5 to 3.5 mA on Side 1 and 0.5 to 35 mA on Side 2.
- What safety certifications does the ISO1540D have?
The device has certifications such as 4242-V Pk isolation per DIN EN IEC 60747-17, 2500-V RMS isolation for 1 minute per UL 1577, CSA approval per IEC 62368-1, and CQC basic insulation per GB4943.1-2011.
- What type of ESD protection does the ISO1540D offer?
The device offers HBM ESD protection of 4 kV on all pins and 8 kV on bus pins.
- What is the package type and pin count of the ISO1540D?
The device comes in an 8-pin SOIC (D) package.
- What are some common applications for the ISO1540D?
Common applications include isolated I2C buses, SMBus and PMBus interfaces, open-drain networks, motor control systems, battery management systems, and I2C level shifting.
- Why is the ISO1540D preferred over optocouplers?
The ISO1540D offers advantages in function, performance, size, and power consumption compared to optocouplers due to its capacitive isolation technology.
- Can the ISO1540D handle clock stretching by the target?
Yes, the ISO1540D is suitable for applications where clock stretching by the target is possible.
