The ISOM8600 are functionally isolated opto-emulator switches that are pin-compatible, drop-in replacements to popular photo-relays. While standard optocouplers use an LED as the input stage, the ISOM8600 uses a current controlled emulated diode as the input stage. The input stage is isolated from the driver stage by TI's proprietary silicon dioxide-based (SiO₂) isolation barrier, which not only provides robust isolation, but also offers best-in-class performance.

The ISOM8600 isolates high voltage signals and offer performance, reliability, and flexibility advantages over traditional optocouplers which age over time. The devices are based on CMOS isolation technology for low-power and high-speed operation, therefore the devices are resistant to the wear-out effects found in optocouplers that degrade performance with increasing temperature, forward current, and device age.

The functional block diagram of the ISOM8600 is shown in Functional Block Diagram. The input signal is transmitted across the isolation barrier using an on-off keying (OOK) modulation scheme. The transmitter sends a high-frequency carrier across the barrier to represent switch-ON state and sends no signal to represent the switch-OFF state. The receiver demodulates the signal after advanced signal conditioning and controls the state of the output MOSFETs. These devices also incorporate advanced circuit techniques to maximize CMTI performance and minimize radiated emissions. Figure 8-2 shows conceptual detail of how the OOK scheme works.