Current sense amplifier
The current sense amplifier addresses noise and offset issues by employing a preamplifier and postamplifier with adjustable resistor networks, ensuring accurate and noise-free current detection in motor drive circuits.
JP2026066125APending Publication Date: 2026-04-16オムニビジョン インテグレーテッド サーキッツ グループ インク
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Patent Information
- Application Number
- JP2024175364
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2024-10-04
- Publication Date
- 2026-04-16
AI Technical Summary
Technical Problem
Current sense amplifiers used in drive circuits for motors face challenges in achieving a single-ended output with minimal noise and offset voltage, particularly when using power MOSFETs that conduct large currents, necessitating external current detection resistors.
Method used
A current sense amplifier design incorporating a preamplifier and postamplifier structure with adjustable resistor networks and operational amplifiers, allowing for setting offset voltage without introducing noise-causing components, and enabling gain adjustment through switchable resistor configurations.
Benefits of technology
The design achieves precise control of output offset voltage and gain without noise interference, facilitating accurate current detection in drive circuits.
✦ Generated by Eureka AI based on patent content.
Abstract
To easily set the offset voltage of a post-amplifier.SOLUTION: The preamplifier includes a preamplifier 10 for obtaining a preamplifier positive output vc and a preamplifier negative output vb corresponding to a difference between an upper voltage and a lower voltage of a current detection resistor R0, and a post amplifier 12 having a positive input terminal to which the preamplifier positive output is inputted and a negative input terminal to which the preamplifier negative output is inputted and obtaining a post amplifier output vout. The post-amplifier 12 includes a positive-side input resistor R4b disposed on an input path to the positive input terminal, a negative-side input resistor R4a disposed on an input path to the negative input terminal, a feedback resistor R5 disposed on a feedback path from the post-amplifier output terminal to the negative input terminal, and a resistor network that connects the positive input terminal to a reference power source and a ground and supplies an offset voltage obtained by dividing a voltage of the reference power source to the positive input terminal and has a combined resistance value corresponding to a resistance value of the feedback resistor.SELECTED DRAWING: Figure 1
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