发明名称 |
CMOS output pad driver with variable drive currents ESD protection and improved leakage current behavior |
摘要 |
A configurable circuit for driving an integrated circuit output pad includes two differently-sized arrays of p-channel FETs and two arrays of differently-sized n-channel FETs for driving the pad. A circuit designer selects different ones of the FETs to produce a desired level of n-channel and p-channel drive at the pad. The nonselected p-channel FETs are maintained in a disabled condition by tieing them off to one side of a p-channel FET which is also connected to a n-type island in a substrate in which the circuit is formed. Electrostatic charge is drained from the gates of the disabled FETs through the n-type island when power is not applied to the integrated circuit thereby preventing failure of leakage tests. The nonselected n-channel FETs are similarly tied to one side of an n-channel FET which in turn is tied to a p-type island to achieve the same purpose for the n-channel FETs. A photolithographic mask embodying a configurable circuit is provided to a designer who utilizes a CAD program to lay down polysilicon connections to select the drive transistors and disable the nonselected transistors.
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申请公布号 |
US5436578(A) |
申请公布日期 |
1995.07.25 |
申请号 |
US19930091705 |
申请日期 |
1993.07.14 |
申请人 |
HEWLETT-PACKARD CORPORATION |
发明人 |
BROWN, CHARLES A.;REICK, GEORGE C.;MOORE, CHARLES E. |
分类号 |
H01L27/118;(IPC1-7):H03K19/003 |
主分类号 |
H01L27/118 |
代理机构 |
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代理人 |
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地址 |
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