Digital PWM Controller Using FPGA Serializer for Scalable DC-DC Conversion
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Solution Overview
Problem
Existing PWM controllers for DC-DC power supplies lack scalability and precision in adjusting PWM ON/OFF periods, limiting their application to a small number of instances due to the need for specialized analog circuits.
Innovation Solution
A digital PWM controller using a digital serializer and FPGA technology to generate PWM signals, allowing for flexible design expansion and precise control of PWM parameters, including ON and OFF periods, through a digital feedback loop and configuration parameters memory.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If analog circuits are used to control PWM, then precision in adjusting PWM ON/OFF periods is improved, but scalability and the number of instances that can be realized are limited
Solution Approach 1:
The patent replaces analog circuits with a digital system comprising an FPGA, digital serializer, and delay elements. The digital system uses binary-coded delay values stored in memory to control PWM timing, substituting continuous analog voltage control with discrete digital timing control. This substitution maintains precision while enabling scalable instantiation across multiple DC-DC converters.
Solution Approach 2:
The patent changes the control parameter from analog voltage levels to digital delay values represented in binary code. The delay amount is stored as a configurable parameter in memory, allowing precise adjustment of PWM timing through digital parameter modification rather than analog circuit adjustment. This parameter transformation enables both precision and scalability.
2Reliability
If specialized circuits are used to control PWM, then required ripple on output DC rails is achieved, but the number of instances that can be realized in a given design is limited
Solution Approach 1:
The patent creates a universal digital control module that can be instantiated multiple times to control different DC-DC converters. The FPGA-based controller with digital serializer serves as a multi-functional platform that handles PWM generation, delay adjustment, and feedback control for multiple converter instances, eliminating the need for separate specialized circuits for each instance.
Solution Approach 2:
The patent enables replication of the PWM control function across multiple instances by storing delay values in digital memory and using the same FPGA-based control architecture for each DC-DC converter. Instead of designing specialized analog circuits for each instance, the same digital control module can be copied and instantiated multiple times with different configurable parameters.
3Measurement precision
If analog PWM control is used, then fine granularity adjustments are achieved, but noise and scalability are compromised
Solution Approach 1:
The patent substitutes analog PWM signal generation with a digital system that produces PWM signals through logical operations on binary-coded delay values. The digital serializer converts parallel digital delay data into a serial PWM signal, replacing analog voltage comparison and integration with digital timing control. This substitution reduces noise while maintaining fine granularity through high-resolution digital delay adjustment.
Data Source
AI summary
Various exemplary embodiments relate to a method performed by a pulsewidth modulation (PWM) controller, the method including: receiving a control input including PWM parameters; producing inputs to a digital serializer, wherein the inputs result in a digital serializer output that is pulsewidth modulated according to the PWM parameters; receiving a feedback control input; and modifying inputs to a digital serializer based upon the feedback control input.