CLT01-38SQ7 Digital Input Current Limiter STMicroelectronics CLT01-38SQ7 High-Speed Digital Input Current Limiter provides an 8-line protected digital input termination with serialized state transfer. The CLT01-38SQ7 cuts dissipation (78mW per input) and reduces the count of opto-transistors, enhancing I/O module density. Its 6.25MHz SPI peripheral output serializes the input state transfer to the I/O module controller.