GPIO Level Shifting Driver With Dynamic Output Decoupling
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Solution Overview
Problem
Current GPIOs in IoT devices exhibit high leakage currents, leading to excessive power consumption, which is particularly problematic in battery-powered applications where ultra-low power consumption is desired.
Innovation Solution
A novel output stage circuit design that includes a current sinking circuit and a pull-up circuit using PMOS and NMOS transistors to decouple the output stage from the supply node and ground node based on input signal transitions, reducing current sinking and sourcing, thereby minimizing power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If conventional GPIO circuits are used, then basic input/output functionality is provided, but leakage current is high (greater than 1 microampere in active mode and 20 nanoamperes in standby mode) leading to excessive power consumption
Solution Approach 1:
The patent implements dynamic control of the output stage by using control nodes that can transition between coupled and decoupled states. The first and second control nodes dynamically couple/decouple the PMOS transistors from ground, while the third control node dynamically couples/decouples the output stage from the supply node. This dynamic switching mechanism allows the circuit to adapt its power consumption based on operational requirements, achieving ultra-low leakage currents in standby mode while maintaining functionality in active mode.
Solution Approach 2:
The patent introduces control nodes as intermediary elements between the input signal and the output stage. These control nodes act as mediators that regulate the coupling between the PMOS transistors and the supply/ground nodes. By using these intermediary control nodes, the circuit can precisely control when current paths are established or broken, thereby minimizing leakage currents while maintaining the ability to source and sink current when needed.
2Power
If the output stage is continuously coupled to supply and ground nodes, then current sourcing and sinking capability is maintained, but static power consumption increases due to continuous current paths
Solution Approach 1:
The patent implements periodic action by transitioning the output stage between active and standby states. During active periods, the control nodes couple the PMOS transistors to ground and the output stage to the supply node, enabling current sourcing and sinking. During standby periods, the control nodes decouple these connections, eliminating continuous current paths. This periodic activation/deactivation of current paths allows the circuit to maintain capability when needed while minimizing static power consumption during idle periods.
Solution Approach 2:
The patent uses dynamic switching of the output stage connections through control nodes. The first and second control nodes dynamically control the coupling between PMOS transistors and ground, while the third control node dynamically controls the coupling between the output stage and supply node. This dynamic reconfiguration allows the circuit to have continuous current capability when required while achieving ultra-low static power consumption when in standby mode.
Data Source
AI summary
Disclosed herein is an low power output stage coupled between a supply node and a ground node, configured to drive an output, and controlled by first, second, and third control nodes. A current sinking circuit controlled by an input signal and configured to sink current from the first and second control nodes when the input signal transitions to a first logic level, thereby resulting in decoupling of the output stage from the ground node and sourcing of current to the output by the output stage. When the input signal transitions to a second logic level different than the first logic level, the current sinking circuit sinks current from a third control node, thereby resulting in decoupling of the output stage from the supply node and sinking of current from the output by the output stage.