STMicroelectronics' CLT01-38SQ7 and SCLT3-8BQ7 provide an 8-line protected digital input termination with serialized state transfer. These devices enhance the I/O module density by cutting the dissipation (78 mW per input) and reducing the count of opto-transistors. The 6.25 MHz (CLT01-38SQ7) and 2 MHz (SCLT3-8BQ7) SPI peripheral outputs serialize the input state transfer to the I/O module controller. The SCLT3-8BQ7 has an adjustable digital filter and an LED driver embedded in each type 3 input section.