Demonstration circuit 1733A is an industrial transceiver with integrated step-down regulator and LDO featuring the LT3669. The board operates from 7.5V to 40V when JP7 is set to L+. When the JP7 is set to RES, the minimum input voltage is 16.5V. The board withstands transients up to 60V. The step-down regulator output is 5V. The LDO output is 3.3V. There are two assembly versions. DC1733A-A is for the LT3669 and DC1733A-B is for the LT3669-2. The difference is the LT3669 has an integrated catch diode. The LT3669-2 requires an external catch diode.