1.3 Properties of Open Drain NAND Gates

Introduction

Open Drain (OD) NAND gates are an unusual sort of logic gates. Unlike a traditional logic gate containing both N-channel and P-channel MOSFETs, the OD NAND gates only contain N-channel MOSFETs which means it is only connected to ground. Thus an external power source of 5 volts is connected to the output with a pull-up resistor connecting the two.