High-Voltage Receiver Circuit With Divider-Gated Schmitt Trigger
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Solution Overview
Problem
Integrated circuit designs face challenges in reliably receiving high voltage domain input signals due to reduced internal power supply voltages, leading to signal saturation and the need for complex circuit designs to interface high and low voltage domains, which consume significant chip area.
Innovation Solution
A transistor ladder voltage divider and pass gate circuit are used to divide and process high voltage domain signals, with outputs fed into comparators to generate signals compatible with low voltage domain receiver circuitry, allowing shared interface circuitry for differential and single-ended receivers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If complex circuit designs involving source followers, voltage regulators, and level selection logic are used to interface high voltage domain I/O signals with low voltage domain receiver circuit designs, then reliable signal reception is achieved, but chip area consumption increases significantly
Solution Approach 1:
The patent combines the differential receiver and single-ended receiver into a single unified circuit that shares common components including the transistor ladder voltage divider, pass gate circuit, and Schmitt trigger circuit. This merging eliminates the need for separate interface circuits for each receiver type, significantly reducing chip area while maintaining reliable signal reception for both differential and single-ended signals.
Solution Approach 2:
The unified receiver circuit is designed to handle both differential and single-ended input signals through a single interface structure. The transistor ladder voltage divider and pass gate circuit can process both signal types, and the Schmitt trigger circuit can detect both differential and single-ended transitions, providing multi-functional capability that reduces the overall circuit complexity and area.
2Adaptability or versatility
If separate circuit designs are used for differential receivers and single-ended receivers, then each receiver type can be optimized, but a large amount of area on the chip is consumed
Solution Approach 1:
The patent merges separate differential and single-ended receiver circuits into a single unified structure that shares common components. The transistor ladder voltage divider, pass gate circuit, and Schmitt trigger circuit are shared between both receiver types, eliminating redundant circuitry and reducing chip area while maintaining compatibility with both signal types.
Solution Approach 2:
The unified receiver circuit incorporates multi-functional elements that can process both differential and single-ended signals. The transistor ladder and pass gate circuit are designed to handle both signal types, and the Schmitt trigger circuit can detect transitions in both differential and single-ended modes, providing universal reception capability.
3Ease of operation
If high voltage domain I/O signals are directly connected to low voltage domain receiver circuitry, then connection simplicity is achieved, but signal saturation occurs in the amplifiers
Solution Approach 1:
The patent introduces a transistor ladder voltage divider as an intermediary circuit between the high voltage domain I/O signals and the low voltage domain receiver circuitry. This voltage divider scales down the high voltage signals to appropriate levels for the low voltage domain, preventing amplifier saturation while maintaining a simple direct connection architecture. The pass gate circuit acts as another intermediary element that controls signal transmission based on voltage levels.
Data Source
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AI summary
A high voltage tolerant single ended receiver circuit includes a voltage divider that is operative to divide in half single ended input signals that are greater than the threshold voltages of the voltage divider. A pass gate circuit is operative to receive single ended signals that are below the threshold voltages of the voltage divider. Output from the voltage divider is coupled to a first input of a modified Schmitt trigger circuit to control a high threshold level of the Schmitt trigger circuit. Output from the pass gate circuit is coupled to a second input of the modified Schmitt trigger circuit to control a low threshold level of the Schmitt trigger circuit.