DCDC Peak Current Control With Safe LDO Disable for RF Stability
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Solution Overview
Problem
Existing DC-to-DC converters and LDO regulators experience inefficiencies due to continuous on/off cycling of the LDO regulator, leading to RF performance degradation when analog circuitry fails to manage load current effectively.
Innovation Solution
A digital logic-based system that includes a DCDC load meter and controller to sense load current, adjust peak current settings, and safely enable/disable the LDO regulator based on predetermined thresholds, avoiding unnecessary cycling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the LDO regulator is continuously enabled for load sharing, then the load current can be handled effectively, but the continuous on/off cycling degrades RF performance
Solution Approach 1:
The patent implements dynamic control of the LDO regulator by using a DCDC load meter to continuously monitor the actual load current and adjust the LDO enable state accordingly. The system transitions from static continuous enabling to dynamic conditional enabling based on real-time load measurements, preventing unnecessary cycling when load current is below the threshold.
Solution Approach 2:
The patent introduces a feedback mechanism where the DCDC load meter measures the actual load current and feeds this information back to the control logic. The control logic compares the measured load current against a threshold and adjusts the LDO regulator state accordingly, creating a closed-loop control system that prevents harmful cycling while maintaining reliable load handling.
2Object-affected harmful factors
If the LDO regulator is dynamically controlled based on load current, then RF performance is improved, but the device complexity increases
Solution Approach 1:
The patent introduces a DCDC load meter as an intermediary component that simplifies the control logic. Instead of requiring complex current sensing and comparison circuitry, the load meter provides a ready-to-use measurement signal that can be directly compared against a threshold, reducing the overall control circuit complexity while achieving dynamic LDO control.
Solution Approach 2:
The patent replaces complex analog current sensing and comparison mechanisms with a digital measurement approach using the DCDC load meter. The continuous analog control is substituted with discrete digital states (LDO enabled or disabled) based on threshold comparison, simplifying the control system while maintaining effectiveness.
3Power
If the DCDC converter peak current is increased to handle higher loads, then the load current capacity is improved, but the DCDC converter efficiency decreases
Solution Approach 1:
The patent implements dynamic adjustment of the DCDC converter peak current setting based on actual load conditions. When load current is high, the peak current is increased to maintain capacity. When load current drops below the threshold and LDO is disabled, the peak current is reduced to improve efficiency. This dynamic adaptation resolves the contradiction between maintaining high capacity and achieving high efficiency.
Solution Approach 2:
The patent changes the peak current parameter of the DCDC converter based on operating conditions. By adjusting this critical parameter dynamically - increasing it when needed for load handling and decreasing it when the LDO is disabled - the system optimizes the trade-off between power capacity and energy efficiency.
Data Source
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AI summary
In an example, a device includes a controller and a direct current (DC)-to-DC converter coupled to the controller and configured to provide a load current to a load. The device also includes a low-dropout (LDO) regulator coupled to the DC-to-DC converter. The controller includes digital logic, and the digital logic is configured to determine the load current. The digital logic is configured to turn on the LDO regulator if the load current is above a predetermined threshold. The digital logic is also configured to turn off the LDO regulator if the load current is below the predetermined threshold.