This document generally describes systems, devices, methods, and techniques for variably controlling impedance for a memory device where multiple NVM units (e.g., NVM dies) are accessible over a shared bus. Impedance can be varied using switches that are configured to switch between a NVM unit and an impedance terminal. Switches can be adjusted during operation of a memory device so that a memory controller is connected over a shared bus to a selected single NVM unit and one or more impedance terminals. Impedance terminals can be configured to provide a relatively small load (a smaller load than an NVM unit) that is impedance matched (alone or in combination with other impedance terminals and/or a NVM unit) with a source impedance on a shared bus that is provided by a memory controller.