Differential Receiver Circuit for High-Voltage Signal Level Shifting
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Integrated circuit designs face challenges in reliably receiving high voltage domain signals due to reduced internal power supply voltages, leading to signal saturation and increased chip area requirements for handling both differential and single-ended receivers.
Innovation Solution
A transistor ladder voltage divider and pass gate circuitry 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, and a modified Schmitt trigger circuit handles single-ended signals by adjusting threshold levels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If high voltage domain signals are directly connected to low voltage domain receiver circuitry, then signal reception is simplified, but the amplifier saturates and cannot reliably receive signals
Solution Approach 1:
A voltage divider circuit comprising a first voltage divider and a second voltage divider is introduced as an intermediary between the high voltage domain signal and the low voltage domain amplifier. The first voltage divider attenuates the high voltage signal to a intermediate voltage level, and the second voltage divider further attenuates it to match the low voltage domain. This intermediary structure enables direct connection while preventing amplifier saturation and maintaining signal reception reliability.
2Reliability
If complex circuit designs are used to interface high voltage and low voltage domains, then signal reception reliability is improved, but chip area consumption increases
Solution Approach 1:
The voltage divider circuit merges multiple attenuation stages (first voltage divider and second voltage divider) into a single integrated structure that handles both differential and single-ended signals. By combining these functions into one unified circuit block, the design achieves reliable high voltage signal reception in the low voltage domain while minimizing chip area consumption compared to separate handling circuits.
Solution Approach 2:
The voltage divider circuit is designed to universally handle both differential signals and single-ended signals from the high voltage domain. The same circuit structure performs multiple functions: attenuating high voltage signals, adapting to different signal types, and interfacing with the low voltage domain amplifier, thereby reducing the need for separate dedicated circuits and minimizing overall chip area.
Data Source
Figure 1
Figure 2~3
Figure 4
AI summary
A high voltage tolerant differential receiver circuit includes a voltage divider ladder that is operative to divide in half differential input signals that are greater than threshold voltages of the voltage divider ladder. A pass gate circuit is operative to receive differential input signals that are below the threshold voltage of the voltage divider ladder. Outputs from the voltage divider ladder and the pass gate circuit are provided to separate comparators. Output from the comparators are combined to generate a signal in the voltage domain of receiver circuitry.