The UM4000 and UM4900 series features high power PIN diodes with long carrier lifetimes and thick I-regions. They are especially suitable for use in low distortion switches and attenuators, in HF through S band frequencies. While both series are electrically equivalent, the UM4900 series have higher power ratings due to a shorter thermal path between the chip and package. High charge storage and long carrier lifetime enable high RF levels to be controlled with relatively low bias current.