Method and apparatus for measuring on-chip power supply integrity
First Claim
1. A method for measuring a parameter of a circuit under test, the method comprising:
- (a) charging a first portion of a test circuit up to a first voltage level;
(b) charging a second portion of said test circuit up to a second voltage level;
(c) disconnecting said test circuit from respective voltage terminals providing said first and second voltage levels; and
(d) measuring said parameter of said circuit under test with said test circuit.
6 Assignments
0 Petitions
Accused Products
Abstract
A test circuit and method for measuring power supply integrity is provided. The circuit may be incorporated on-chip and is small enough to be integrated many times across the surface of the die for measuring integrity parameters at several locations on the chip. The circuit instantaneously measures, e.g., the rail voltage of a power supply, which may be fluctuating at the time of measurement. In addition, the circuit isolates itself from all chip power rails for the duration of the measurement, thereby eliminating any influence of external noise on the measurement. A storage capacitor is charged up to full power rail voltage for powering up a comparator. Then, the comparator is isolated from the power rails and the measurements are taken. Based upon the measurements, certain power supply integrity parameters are quantified including ground bounce and power droop.
18 Citations
49 Claims
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1. A method for measuring a parameter of a circuit under test, the method comprising:
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(a) charging a first portion of a test circuit up to a first voltage level;
(b) charging a second portion of said test circuit up to a second voltage level;
(c) disconnecting said test circuit from respective voltage terminals providing said first and second voltage levels; and
(d) measuring said parameter of said circuit under test with said test circuit. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22)
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23. A test circuit for measuring a parameter of a circuit under test, said test circuit comprising:
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a first charging portion for charging a first portion of said test circuit to a first voltage level;
a second charging portion for charging a second portion of said test circuit to a second voltage level;
respective switches within said first and second charging portions for disconnecting said test circuit from terminals respectively providing said first and second voltage levels; and
a measuring portion for measuring a parameter of said circuit under test while said test circuit is disconnected from said terminals. - View Dependent Claims (24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35)
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36. A semiconductor die comprising:
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at least one circuit to be tested; and
at least one test circuit for measuring a parameter of said at least one circuit to be tested, said at least one test circuit comprising;
a first charging portion for charging a first portion of said at least one test circuit to a first voltage level;
a second charging portion for charging a second portion of said at least one test circuit to a second voltage level;
respective switches within said first and second charging portions for disconnecting said at least one test circuit from terminals respectively providing said first and second voltage levels; and
a measuring portion for measuring said parameter of said at least one circuit to be tested while said at least one test circuit is disconnected from said terminals. - View Dependent Claims (37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47)
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48. A semiconductor die comprising:
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at least one circuit to be tested; and
at least one test circuit for measuring a parameter of said at least one circuit to be tested, said at least one test circuit comprising;
a comparator coupled to a power source, said comparator having a first input for receiving a sensed voltage and a second input for receiving a reference voltage;
a first storage capacitor coupled to said power source and also coupled to said comparator, said first storage capacitor being used for storing a voltage supplied by said power source and also for providing power to said comparator when said comparator is disconnected from said power source;
a second storage capacitor coupled to a reference voltage source and also coupled to said second input of said comparator, said second storage capacitor being used for storing a reference voltage provided by said reference voltage source and also for providing said second input of said comparator with said reference voltage when said comparator is disconnected from said reference voltage source. - View Dependent Claims (49)
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Specification