EFFICIENT POWER SUPPLY NOISE MEASUREMENT BASED ON TIMING UNCERTAINTY
A power supply noise measurement device for inclusion with an integrated circuit, the integrated circuit having a functional block, the noise measurement device comprising: a signal generator configured to provide a clock signal to the functional block, an antenna comprising a transistor, and being located proximate to the functional block, the antenna being configured to receive the clock signal from the signal generator, and a jitter estimator configured to provide a measure of the relative jitter between a signal output from the antenna and a reference clock signal, wherein the transistor of the antenna receives electrical power from the same power source that delivers power to the functional block.
1 . A power supply noise measurement device for use with an integrated circuit, the integrated circuit having a functional block, the noise measurement device comprising:
a signal generator configured to provide a clock signal to the functional block,
an antenna comprising a transistor, and being located proximate to the functional block, the antenna being configured to receive the clock signal from the signal generator, and
a jitter estimator configured to provide a measure of the relative jitter between a signal output from the antenna and a reference clock signal, and the transistor of the antenna receives electrical power from the same power source that delivers power to the functional block.
2 . A power supply noise measurement device according to claim 1 , wherein the antenna comprises a buffer, the buffer comprising a plurality of transistors configured to relay the clock signal from an input of the buffer to an output of the buffer.
3 . A power supply noise measurement device according to claim 2 , wherein the antenna comprises a plurality of buffers electrically connected in a daisy-chain fashion, whereby the output of buffers in the daisy-chain are connected to the input of the subsequent buffer in the daisy-chain.
4 . A power supply noise measurement device according to claim 1 , wherein the power to the, or each, transistor in the antenna is taken from a mesh of electrical contacts that also provides electrical power to components within the functional block.
5 . A power supply noise measurement device according to claim 1 , wherein the functional block, antenna and jitter estimator are all located within a voltage domain, and wherein a common power source supplies power to the voltage domain.
6 . A power supply noise measurement device according to claim 1 , wherein the antenna is formed as a part of the functional block.
7 . A power supply noise measurement device according to claim 1 , further comprising a multiplexer, wherein the multiplexer is configured to selectably transfer either the clock signal from the signal generator, or the signal output from the antenna, to the jitter estimator.
8 . A power supply noise measurement device according to claim 1 , wherein a plurality of antennas are provided in or proximate to the functional block, each of the antennas being configured to receive the clock signal from the signal generator, and each being configured to provide an input to the jitter estimator.
9 . A power supply noise measurement device according to claim 1 , wherein the reference clock signal is provided by the signal generator.
10 . A power supply noise measurement device according to claim 1 , wherein the reference clock signal is provided by a signal generator external to the integrated circuit.
11 . A power supply noise measurement device according to claim 1 , further comprising a second multiplexer configured to selectable provide the reference clock signal either from a signal generator located on the integrated circuit, or from a signal generator external to the integrated circuit.
12 . A power supply noise measurement device according to claim 1 , wherein the measure of the relative jitter provided by the jitter estimator comprises information relating to the temporal variation of the jitter.
13 . A method of providing a power supply noise measurement for an integrated circuit, the integrated circuit having a functional block, the method comprising:
providing a signal generator for providing a clock signal to the functional block,
providing an antenna comprising a transistor, and located proximate to the functional block, the antenna being configured to receive the clock signal from the signal generator, and
determining a measure of the power supply noise by analyzing the relative jitter between a signal output from the antenna and a reference clock signal,
and the transistor of the antenna receives electrical power from the same power source that delivers power to the functional block.
14 . An integrated circuit comprising the power supply noise measurement device according to claim 12 .