The HIP408x family of driver ICs includes the HIP4080A, HIP4081A, HIP4082, HIP4083 and HIP4086. The inputs to all of these devices have internal 100A (typical) pull-ups to VDD except for HEN (HIP4080A), which has an internal 200A (typical) pull-up to VDD. If left open, the voltage on these inputs may not be sufficiently large to guarantee a logic high (2.5V@25C and 2.7V over temperature). If a logic high is desired, we recommend connecting the inputs to VDD through a resistance no larger than 25k. The inputs may also be connected directly to VDD.