High-Voltage Level Shifter Without De-Glitch Delay Penalty
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Solution Overview
Problem
Conventional high voltage transistor drivers experience significant propagation delay, especially when switching voltages above 200 volts, and are not cost-effective, while including de-glitch filters to prevent signal disturbances increases delay further.
Innovation Solution
The implementation of blocking circuitry in high voltage level shifters that monitors signal voltages on the ON and OFF pulse lines to inhibit driver transitions caused by common mode transients, eliminating the need for de-glitch filters and reducing propagation delay.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If conventional high voltage transistor drivers are used to switch voltages above 200 volts, then the driver can handle high voltage, but the propagation delay becomes significant (excessive delay)
Solution Approach 1:
The driver circuit is segmented into multiple independent functional blocks: a pulse generator that creates ON and OFF pulses, a blocking circuit that filters common mode transients, and a latch circuit that generates the final drive signal. This segmentation allows each block to be optimized independently, achieving fast response while maintaining immunity to transient disturbances.
Solution Approach 2:
The blocking circuit acts as an intermediary between the pulse generator and the latch circuit. It receives both ON and OFF pulses, compares their timing and validity, and only passes legitimate transitions to the latch. This intermediary block eliminates erroneous transitions caused by common mode transients without requiring slow de-glitch filters, thus maintaining fast propagation delay.
2Reliability
If de-glitch filters are added to prevent signal disturbances, then immunity to erroneous transitions is improved, but propagation delay increases further
Solution Approach 1:
The blocking circuit performs preliminary validation of ON and OFF pulses before they reach the latch circuit. By checking pulse validity and timing in advance, it prevents erroneous transitions from propagating further, eliminating the need for slow de-glitch filters and maintaining fast response times.
Solution Approach 2:
The patent replaces the traditional mechanical/electronic de-glitch filter approach with a digital logic-based blocking circuit that uses pulse comparison and timing validation. This substitution achieves the same filtering function with significantly faster response, reducing propagation delay while maintaining immunity to transient disturbances.
3Ease of manufacture
If conventional transistor driver circuits are used, then the circuit implementation is straightforward, but the propagation delay is excessive for high voltage switching
Solution Approach 1:
The driver is divided into three simple, modular blocks: pulse generator, blocking circuit, and latch circuit. Each block performs a single, well-defined function, making the overall circuit easier to manufacture and debug despite the performance improvement. The modular structure allows standard fabrication processes to be used.
Solution Approach 2:
The patent changes the operational parameters of the driver circuit by using rapid pulse generation and blocking based on pulse timing rather than continuous signal processing. This parameter change enables fast switching (30 ns or less propagation delay) while maintaining ease of manufacture through standard digital logic implementation.
Data Source
AI summary
A lever shifter includes an output driver and a high-side gate driver. The high-side gate driver is configured to drive the high-side output transistor, and is coupled to an on pulse signal line that conducts an on pulse, and is coupled to an off pulse signal line that conducts an off pulse. The high-side gate driver includes a blocking circuit configured to enable generation of a drive signal to the high-side output transistor based on a voltage of a first of the on or off pulse signal line being greater than a first predetermined amount and a voltage of a second of the on or off signal line being less than a second predetermined amount.