公开(公告)号：US07215175B1

公开(公告)日：2007-05-08

申请号：US10932162

申请日：2004-09-01

申请人： Gurupada Mandal ,  Suresh Seshadri ,  David Hugh McIntyre ,  Raymond A. Heald ,  William Y. Mo

发明人： Gurupada Mandal ,  Suresh Seshadri ,  David Hugh McIntyre ,  Raymond A. Heald ,  William Y. Mo

IPC分类号： H01H37/76 ,  H01H85/00

CPC分类号： G11C17/18

摘要： An improved circuit for sensing and programming fuses in integrated circuits. The circuit is broadly comprised of a fuse cell, a reference circuit, a sense amplifier and a level detector. In one embodiment of the present invention, a two-stage sensing scheme is implemented. The improved fuse sensing circuit uses current-mode sensing and implements an auto-read current reduction scheme. Using a level-detect circuit, the virtual ground is raised automatically if the high-voltage power supply exceeds core supply (Vdd) by a fixed dc voltage. This reduces effective sensing voltage and the read current and thus helps preserve unblown fuse integrity. In one embodiment of the invention, four modes of operation are implemented: “Normal Read,” “Unblown_Read,” “Blown_Read_1” and “Blown_Read_2.” The default read mode is the “normal read” while the “Unblown” and “Blown” read modes are for fuse calibration purposes. In the “Unblown_Read” read mode, the circuit is operable to compare the fuse resistance against a lower reference resistance, closer to an unblown fuse resistance value, in order to make the comparison more stringent. Similarly, the “Blown_Read_1” and “Blown_Read_2” modes allow a more stringent comparison for a blown fuse resistance.

摘要翻译： 一种用于在集成电路中感测和编程保险丝的改进电路。 该电路广泛地包括熔丝单元，参考电路，读出放大器和电平检测器。 在本发明的一个实施例中，实现了两级感测方案。 改进的熔丝感测电路使用电流模式感测并实现自动读取电流降低方案。 使用电平检测电路，如果高压电源以固定的直流电压超过磁芯电源（Vdd），则虚拟接地将自动升高。 这降低了有效的感测电压和读取电流，从而有助于保持未熔断的保险丝完整性。 在本发明的一个实施例中，实现了四种操作模式：“Normal Read”，“Unblown_Read”，“Blown_Read_1”和“Blown_Read_2”。 “Unblown”和“Blown”读取模式的默认读取模式是“正常读取”，用于保险丝校准。 在“Unblown_Read”读取模式下，该电路可操作以将熔丝电阻与较低的参考电阻进行比较，更接近未熔断的保险丝电阻值，以使比较更加严格。 类似地，“Blown_Read_1”和“Blown_Read_2”模式允许对熔断熔断器电阻进行更严格的比较。