| 摘要 |
PURPOSE: To protect an output buffer of an integrated circuit from being damaged by electrostatic discharge by providing an electrostatic discharge protection resistance means having a specified resistance and an excessive voltage clamp means connected to a bond pad. CONSTITUTION: Between a node 13 and a output bond pad 17, a resistor 14 of silicide is connected. Further, voltage clamp diodes 15 and 16 are connected to the bound pad 17 and power source conductors VDD and VSS, in respective directions. The diodes 15 and 16 are so assigned, surrounding the periphery of the bound pad 17, that resistance and inductance are minimum, thus fast clamp operation is assured for maximum protection. When a relatively small output buffer drives a small load, rather high resistance value is appropriate. A value up to about 20Ω is through to be effective for a small output buffer, meanwhile, a value as low as about 1Ω is yet effective protection as considering high effect due to relatively large output buffer. |
