40+ Year Lifespan: TI's ISOM811 & ISOM871 Isolators

Texas Instruments (TI) has recently unveiled a new range of optocoupler simulators, aimed at elevating signal integrity, reducing power consumption, and extending the longevity of high-voltage applications in both industrial and automotive sectors. TI is introducing two distinct series: the ISOM811 series for digital input-output, and the ISOM871 series for analog input-output. These groundbreaking devices are now available for sampling, accompanied by evaluation boards for those interested in exploring their capabilities.

Distinguished from conventional optocouplers, TI's optocoupler simulators are founded on silicon dioxide-based isolation technology, which effectively circumvents issues related to aging, as they do not employ light-emitting components. Moreover, the uniformity of their manufacturing processes and chip production guarantees a high level of consistency. These innovative products have undergone rigorous testing, satisfying IEC60747-17 standards and boasting a projected lifespan exceeding 40 years.

Michael Schultis, Market and Applications Manager for TI's Isolation Interface, illustrates their applicability by noting their previous reliance on silicon dioxide (SiO2)-based digital isolators for the isolation feedback pathway in isolated power supplies. These have now been superseded by analog isolators built on silicon dioxide technology, offering a viable alternative to analog optocouplers.

Within the feedback pathway, TI's optocoupler simulators transmit proportional analog signals from right to left, achieving current-to-current isolation. They can serve as a direct replacement for optocouplers in isolated power supplies and offer a plethora of advantages:

1. Stable CTR Across Temperature Range: The Current Transfer Ratio (CTR) remains consistent over a broad temperature spectrum, ensuring a uniform isolation gain irrespective of temperature variations.

2. Mitigation of Aging Issues: In contrast to traditional optocouplers plagued by aging concerns, TI's devices exhibit remarkable uniformity, allowing for more streamlined design margins.

3. Enhanced Bandwidth: These products outperform traditional optocouplers with their expanded bandwidth, leading to improved transient response of loads and cost reduction through diminished output capacitance requirements, thereby lowering overall system costs.

4. Extended Lifespan: Leveraging silicon-based analog isolation technology, TI's offerings boast a substantially longer lifespan than conventional optocouplers, ensuring prolonged power supply reliability.

TI has consistently invested in enhancing isolation barrier technology to address challenges such as lifespan and to meet increasingly stringent requirements, including Common-Mode Transient Immunity (CMTI). Michael Schultis emphasizes that "In terms of this critical parameter, the ISOM8 series surpasses traditional optocouplers by nearly tenfold, achieving 125kV/μs. Furthermore, optocoupler simulators support a wide temperature range from -55°C to 125°C, with CTR remaining stable throughout the entire temperature spectrum."