ISO1540D - 2.5kVrms I2C Digital Isolator | Texas Instruments
MPN: ISO1540D ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $2.85 | $2.85 |
| 10 | $2.56 | $25.60 |
| 100 | $2.28 | $228.00 |
| 500 | $2.05 | $1,025.00 |
| 1,000 | $1.85 | $1,850.00 |
Drop-in alternatives for ISO1540D — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ISO1540DR
✅ Drop-In📋 Reference alternative (not in catalog)
ISO1541D
✅ Drop-In📋 Reference alternative (not in catalog)
ISO1540QDQ1
✅ Drop-In📋 Reference alternative (not in catalog)
ADUM1250ARZ
✅ Drop-In✓ In Stock
$1.85 / Unit
View Datasheet →ISO7220ADR
✅ Drop-In📋 Reference alternative (not in catalog)
ISO1540D Maximum Ratings & Electrical Characteristics
| Isolation Rating | 2500 Vrms |
| Number of Channels | 2 |
| Type | I2C Digital Isolator |
| Data Rate | 1 Mbps |
| CMTI | 25 kV/µs |
| Supply Voltage Range | 3 V to 5.5 V |
| Propagation Delay | 67 ns |
| Side 1 Sink Current | 3.5 mA |
| Side 2 Sink Current | 35 mA |
| Operating Temperature | -40°C to +125°C |
| Package | 8-SOIC (0.154", 3.90mm Width) |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant |
| Isolation Technology | Capacitive (SiO2 barrier) |
| Output Type | Open-Drain |
ISO1540D Pin Configuration
| Pin 1 | SDA1 — Serial data line, Side 1 |
| Pin 2 | SCL1 — Serial clock line, Side 1 |
| Pin 3 | GND1 — Ground, Side 1 |
| Pin 4 | VCC1 — Supply voltage, Side 1 |
| Pin 5 | VCC2 — Supply voltage, Side 2 |
| Pin 6 | GND2 — Ground, Side 2 |
| Pin 7 | SCL2 — Serial clock line, Side 2 |
| Pin 8 | SDA2 — Serial data line, Side 2 |
Safe Operating Area (SOA) & Thermal Characteristics
No official SOA curve available for this digital IC. Always operate within absolute maximum ratings specified in the datasheet. Ensure adequate cooling and derate as needed.
Typical Applications
ISO1540D is suitable for 6 applications: Industrial Automation, Medical Monitoring, Battery Management Systems, Power Converters, Motor Drives, Isolated Sensor Interfaces.
Industrial Automation
The ISO1540D provides galvanic isolation for I2C buses in industrial control systems, protecting against ground loops and voltage transients. Its 2500Vrms isolation and 25kV/µs CMTI ensure reliable communication in noisy factory environments. The 1-Mbps data rate supports fast sensor and actuator communication, while the wide supply range (3V to 5.5V) allows interfacing with various logic levels. The device's low propagation delay (67ns) maintains I2C timing integrity over long cable runs.
Recommended
Medical Monitoring
In medical devices, the ISO1540D isolates patient-connected sensors from the control electronics, ensuring safety and preventing leakage currents. Its 2500Vrms isolation meets basic safety requirements, and the low power consumption is ideal for battery-powered monitors. The bidirectional I2C interface simplifies communication with sensors like temperature and pressure monitors. The device's small 8-SOIC package saves board space in compact medical devices.
Recommended
Battery Management Systems
The ISO1540D isolates the I2C bus between battery cells and the management controller, preventing ground loops and ensuring accurate voltage monitoring. Its 1-Mbps data rate handles fast cell voltage updates, and the 3V to 5.5V supply range accommodates different battery voltages. The high CMTI (25kV/µs) ensures immunity to switching noise from power converters. The device's open-drain outputs with 35mA sink capability on Side 2 drive long bus traces.
Recommended
Power Converters
In power converters, the ISO1540D isolates the control I2C bus from the high-voltage power stage, protecting low-voltage controllers. Its 2500Vrms isolation withstands high-voltage transients, and the 25kV/µs CMTI prevents false triggering from fast switching. The device supports 1-Mbps communication for real-time control loops. The wide supply range allows direct connection to 3.3V or 5V controllers, simplifying design.
Recommended
Motor Drives
The ISO1540D provides isolation for I2C communication between the motor controller and sensors, preventing noise from the motor windings from corrupting signals. Its high CMTI (25kV/µs) ensures reliable operation in the presence of high dv/dt transients. The 1-Mbps data rate supports fast sensor feedback for precise motor control. The device's robust operating temperature range (-40°C to +125°C) suits harsh industrial environments.
Recommended
Isolated Sensor Interfaces
The ISO1540D is ideal for isolating I2C sensors in remote locations, such as temperature, pressure, or gas sensors. It provides 2500Vrms isolation to protect the main controller from ground potential differences. The bidirectional I2C interface allows both reading and writing to sensor registers. The device's low power consumption is suitable for field-powered sensors, and its small package fits in space-constrained enclosures.
Recommended
Recommended Products Summary
Engineering reference data for ISO1540D — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ISO1540DR | ISO1541D | ISO1540QDQ1 | ADUM1250ARZ |
|---|---|---|---|---|---|
| Package | 8-SOIC | 8-SOIC | 8-SOIC | 8-SOIC | 8-SOIC |
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Analog Devices |
| Isolation Rating | 2500 Vrms | 2500 Vrms | 2500 Vrms | 2500 Vrms | 2500 Vrms |
| Data Rate | 1 Mbps | 1 Mbps | 1 Mbps | 1 Mbps | 1 Mbps |
| CMTI | 25 kV/µs | 25 kV/µs | 25 kV/µs | 25 kV/µs | 25 kV/µs |
| Supply Voltage | 3V to 5.5V | 3V to 5.5V | 3V to 5.5V | 3V to 5.5V | 3V to 5.5V |
| Propagation Delay | 67 ns | 67 ns | 67 ns | 67 ns | 67 ns |
| Channel Configuration | Bidirectional clock and data | Bidirectional clock and data | Unidirectional clock, bidirectional data | Bidirectional clock and data | Bidirectional clock and data |
Key Differentiators
- Bidirectional I2C isolation without external direction control (vs ISO7220ADR)
- Higher sink current on Side 2 (35mA) vs typical I2C isolators (vs ADUM1250ARZ)
- Automotive-grade variant available (vs ISO1540QDQ1)
Design Notes
Place the ISO1540D close to the isolation barrier to minimize trace length and reduce EMI. Use separate ground planes for Side 1 and Side 2, and avoid routing high-speed signals across the barrier. Add decoupling capacitors (0.1µF) on both VCC1 and VCC2 pins, placed as close as possible to the device.
Ensure pull-up resistors are connected on both SDA and SCL lines on both sides of the isolator. The pull-up value should be chosen based on bus capacitance and speed; for 1-Mbps operation, typical values are 1kΩ to 10kΩ. Failure to include pull-ups will result in undefined bus states.
The ISO1540D has low power dissipation, typically less than 100mW, so thermal management is not critical. However, in high-temperature environments (up to 125°C), ensure the PCB layout provides adequate heat dissipation through copper pours and vias to keep the junction temperature within limits.
Compliance Information
RoHS compliant per TI product page. AEC-Q100 qualification available on ISO1540QDQ1 variant.
