发明名称 |
CMOS differential input buffer with source-follower input clamps |
摘要 |
A differential input buffer shows reduced sensitivity to input conditions such as input-trace loading and upstream driver characteristics. Varying input conditions can be measured as differences in amplitude, slew rate, and common-mode offset. Wide input-voltage swings are clamped to a limited voltage range by an input clamp circuit that uses source followers to drive p-channel clamp transistors that turn off when the input voltage is too low. A voltage divider then sets the lowest voltage input to a differential stage. The differential stage receives the clamped inputs and has two tail current sinks to reduce delay sensitivity to charging and discharging of tail capacitances. A middle voltage is applied to transistors opposite the differential transistors that receive the clamped input voltages. A bias voltage for the tail current sinks is generated by mirroring currents and setting a gate voltage by injecting and removing a same bias current from a resistor.
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申请公布号 |
US6801080(B1) |
申请公布日期 |
2004.10.05 |
申请号 |
US20030249414 |
申请日期 |
2003.04.07 |
申请人 |
PERICOM SEMICONDUCTOR CORP. |
发明人 |
ARCUS CHRISTOPHER G. |
分类号 |
G06G7/26;(IPC1-7):G06G7/26 |
主分类号 |
G06G7/26 |
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