Invention Grant
- Patent Title: Large loading split I/O driver with negligible crowbar
- Patent Title (中): 大容量分流I / O驱动器,可以忽略不计
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Application No.: US11055228Application Date: 2005-02-10
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Publication No.: US07317333B1Publication Date: 2008-01-08
- Inventor: Shi-dong Zhou , Andy T. Nguyen
- Applicant: Shi-dong Zhou , Andy T. Nguyen
- Applicant Address: US CA San Jose
- Assignee: Xilinx, Inc.
- Current Assignee: Xilinx, Inc.
- Current Assignee Address: US CA San Jose
- Agent Thomas A. Ward; Kin-Wah Tong
- Main IPC: H03K19/0175
- IPC: H03K19/0175

Abstract:
A pre-driver for large I/O pull-up and pull-down transistors is provided so that the I/O pull-up and pull-down transistors do not experience crowbar current, and the pre-driver circuit likewise does not experience crowbar current or require large driver transistors. One pre-driver circuit includes two NAND gates and two NOR gates with delay circuitry provided by two series inverters from a data input to a first node, and two additional series inverters from the first node to a second node. A further pre-driver circuit includes feedback from the pre-driver outputs to ensure its NMOS and PMOS transistors do not turn on together to create crowbar, while allowing faster switching. With the pre-driver circuit embodiments, a conventional level shifter can be used. Further with the pre-driver circuitry, slew rate control can be provided in the pull-up and pull-down driver circuitry, rather than in the pre-driver circuitry.
Information query
IPC分类: