Additional Peripheral Power Management Considerations
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SPRUH82C – April 2013 – Revised September 2016
Copyright © 2013–2016, Texas Instruments Incorporated
Power Management
9.10.5 Pull-Up/Pull-Down Disable
In general, you must ensure that all input pins are always pulled to a logic-high or a logic-low voltage level.
A floating input pin can consume a small amount of I/O leakage current. The I/O leakage current can be
greatly multiplied in the case of several floating inputs pins.
This device includes internal pull-up and pull-down resistors that prevent floating input pins. These internal
resistors are generally very weak and their use is intended for pins that are not connected on the board
design. For pins that are connected, external pull-up and pull-down resistors are recommended.
When an input pin is externally driven to a valid logic level, through an external pull-up resistor or by an
external device for example, it is recommended to disable the internal resistor. Opposing an internal pull-
up or pull-down resistor can consume a small amount of current. Internal resistors are disabled through
the pullup/pulldown enable register (PUPD_ENA) in the
System Configuration (SYSCFG) Module
chapter.