Driver Circuit Power Sequencing for Overvoltage Protection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional driver circuits cannot perform high-speed, large-amplitude operations due to the destruction of transistors caused by overvoltage, which limits their ability to handle higher data transmission speeds beyond 3 Gbps.
Innovation Solution
Incorporating a pre-driver and main-driver circuit with overvoltage protection sequence control, using switches between power supplies and an overvoltage protection sequence circuit to prevent overvoltage application, allowing the use of low-withstand-voltage (high-speed) transistors for the main-driver.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If high-voltage power supply is connected to main-driver using high-speed transistors, then data transmission speed is improved, but transistor destruction occurs due to overvoltage
Solution Approach 1:
The overvoltage protection sequence circuit performs preliminary action by controlling the power supply connection sequence - it ensures that the low-voltage power supply is connected to the pre-driver first, then subsequently connects the high-voltage power supply to the main-driver. This preliminary sequencing prevents overvoltage damage before it can occur, enabling the use of high-speed low-withstand-voltage transistors in the main-driver while maintaining reliability.
2Speed
If low-withstand-voltage transistors are used in main-driver, then operation speed is improved, but withstand voltage capability deteriorates
Solution Approach 1:
The overvoltage protection sequence circuit acts as an intermediary between the high-voltage power supply and the low-withstand-voltage transistors in the main-driver. It mediates the voltage application by controlling the switching sequence, ensuring that high voltage is only applied after the transistors are properly initialized and protected, thus allowing high-speed transistors to operate safely at high voltages.
3Power
If pre-driver and main-driver are connected in sequence, then signal amplification is improved, but circuit complexity increases
Solution Approach 1:
The overvoltage protection sequence circuit merges the power supply control functions for both the pre-driver and main-driver into a single integrated control mechanism. By combining the sequencing logic and switch control in one circuit block, the patent achieves signal amplification through the cascaded pre-driver and main-driver while minimizing the increase in overall circuit complexity.
Data Source
AI summary
A driver circuit including a pre-driver B1 that operates by receiving operating power from a first power supply VDDI, and a main-driver B2 that receives operating power from a second power supply VDDE, amplifies an output signal from the pre-driver B1, and outputs the amplified signal. It also includes a first switch B4 between the first power supply VDDI and the pre-driver B1. It also includes a second switch B5 between the second power supply VDDE and the main-driver B2. A overvoltage protection sequence circuit B3 controls the On/Off states of the first switch B4 and the second switch B5 to controls the On/Off order of the pre-driver B1 and the main-driver B2. By doing so, the overvoltage protection sequence circuit B3 prevent an overvoltage from being applied to the driver circuit, especially to the main-driver B2.