Semiconductor Switch Multiple Sense Terminals Current Measurement
Solution Overview
Problem
Existing semiconductor switches face challenges in accurately determining current over a large dynamic range due to nonlinear relationships between collector-emitter current and voltage, leading to limited accuracy at high or low currents and increased energy consumption.
Innovation Solution
A semiconductor switch with multiple sense terminals, each providing a current proportional to the power path current, allowing for optimized measurement signals across different ranges, and an evaluation circuit to select the appropriate sense terminal based on current levels for precise current determination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If a relatively large translation ratio is chosen for high maximum currents, then the measurement range is extended, but the accuracy for small currents deteriorates due to disturbance effects and offset errors
Solution Approach 1:
The patent divides the current measurement into multiple segments by providing several sense terminals (first sense terminal for high currents, second sense terminal for low currents). Each sense terminal is optimized for a specific current range, allowing the system to segment the overall measurement range into distinct zones with appropriate measurement strategies for each zone.
Solution Approach 2:
The patent implements dynamic switching between different sense terminals based on the detected current level. The evaluation circuit automatically selects which sense terminal to use depending on whether the current is high or low, making the measurement system adaptive and dynamic rather than static.
2Measurement precision
If a small translation ratio is chosen for high accuracy at low currents, then measurement precision is improved, but the compensation current increases and may cause signal limitations even at high currents
Solution Approach 1:
The patent segments the measurement function across multiple sense terminals with different translation ratios. The first sense terminal uses a translation ratio optimized for high currents, while the second sense terminal uses a different ratio optimized for low currents, eliminating the need for a single compensation current setting to satisfy both extremes.
Solution Approach 2:
The patent changes the translation ratio parameter depending on the current level being measured. By switching between different sense terminals with different translation ratios, the system adapts the measurement parameters to match the operating conditions, optimizing both accuracy and compensation current requirements for each range.
3Device complexity
If a single sense terminal is used for all current levels, then device complexity is reduced, but measurement precision deteriorates over a large dynamic range
Solution Approach 1:
The patent makes the sense terminal system multi-functional by providing multiple sense terminals that can be selectively activated. The evaluation circuit universally handles both high-current and low-current measurements by automatically selecting the appropriate sense terminal, making the overall system capable of functioning accurately across the entire current dynamic range.
Data Source
AI summary
The invention relates to a semiconductor switch and to a method for determining a current in the power path of a semiconductor switch. For this purpose, a semiconductor switch, according to the invention, has a plurality of sense connections, wherein each of said sense connections provides an individual output signal that is proportional to the current in the power path of the semiconductor switch. The evaluation of the current in the power path can be optimized by the appropriate selection of one of the plurality of sense connections in accordance with the current in the power path of the semiconductor switch.