发明名称 |
Impedance mismatch detection circuit |
摘要 |
A comparison circuit for detecting impedance mismatch between pull-up and pull-down devices in a circuit to be monitored includes a comparator operative to receive first and second signals and to generate, as an output, a third signal indicative of a difference between the first and second signals. A first signal generator is operative to generate the first signal indicative of a difference between reference pull-up and pull-down currents that is scaled by a prescribed amount. The reference pull-up current is indicative of a current flowing through at least one corresponding pull-up transistor device in the circuit to be monitored. The pull-down reference current is indicative of a current flowing through at least one corresponding pull-down transistor device in the circuit to be monitored. A second signal generator connected with the second input of the comparator is operative to generate the second signal as a reference voltage defining a prescribed impedance mismatch threshold associated with the circuit to be monitored. |
申请公布号 |
US8803535(B2) |
申请公布日期 |
2014.08.12 |
申请号 |
US201113171725 |
申请日期 |
2011.06.29 |
申请人 |
LSI Corporation |
发明人 |
Kothandaraman Makeshwar;Kumar Pankaj;Parameswaran Pramod |
分类号 |
G01R27/26;H03F3/45 |
主分类号 |
G01R27/26 |
代理机构 |
Otterstedt, Ellenbogen & Kammer, LLP |
代理人 |
Otterstedt, Ellenbogen & Kammer, LLP |
主权项 |
1. A comparison circuit for detecting impedance mismatch between pull-up and pull-down devices in a circuit to be monitored, the comparison circuit comprising:
a comparator operative to receive first and second signals and to generate, as an output of the comparison circuit, a third signal indicative of a difference between the first and second signals; a first signal generator connected with a first input of the comparator and operative to generate the first signal indicative of a difference between reference pull-up and pull-down currents that is scaled by a prescribed amount, the reference pull-up current being indicative of a current flowing through at least one corresponding pull-up transistor device in the circuit to be monitored, the reference pull-down current being indicative of a current flowing through at least one corresponding pull-down transistor device in the circuit to be monitored; and a second signal generator connected with a second input of the comparator and operative to generate the second signal as a reference voltage defining a prescribed impedance mismatch threshold associated with the circuit to be monitored. |
地址 |
San Jose CA US |