Stmicroelectronics R&d (shanghai) Co. Ltd.

Stmicroelectronics R&d Co. Ltd. (shanghai)

Sarah Gao

Jianhua Zhao

Wadeo Ou

David Peng

A linear voltage regulator includes a Miller frequency compensation having a movable zero, which tracks the frequency of the load pole as the load condition changes. The compensated voltage regulator maintains stability under variable load conditions. Because of the Miller effect, DC open-loop gain and bandwidth are not sacrificed for stability. The compensated voltage regulator can therefore maintain high power supply rejection ratio (PSRR).

Adaptive miller compensated voltage regulator

An embodiment of a circuit for driving an under-damped system comprises first and second signal generators. The first generator is operable to generate a first drive signal. And the second generator is operable to receive the first drive signal and a second drive signal, and to generate from the first and second drive signals a system drive signal having a first amplitude for a first duration and having a second amplitude after the first duration, the system drive signal operable to cause the under-damped system to operate in a substantially damped manner. Either or both of the first and second generators may be programmable such that one may adjust the response of any under-damped system by generating an appropriate drive signal instead of by physically modifying the system itself. In another embodiment, an under-damped system is caused to oscillate at a damped frequency having a first phase, and is also caused to oscillate at substantially the damped frequency having a second phase such that the oscillation at the first phase substantially cancels the oscillation at the second phase. Such embodiments may allow one to realize a faster settling time without slowing down the response time of an under-damped system.

Improving the response of an under-damped system

A buffer circuit includes a biasing circuit operable to generate first and second biasing signals. A capacitive network includes an input adapted to receive an input signal and the capacitive network is operable responsive to the input signal to generate first and second bootstrapped signals. A push-pull stage includes first and second control inputs and an output. The push-pull stage is coupled to the biasing circuit to receive the first and second biasing signals on the first and second control inputs, respectively, and is coupled to the capacitive network to receive the first and second bootstrapped signals on the first and second control inputs, respectively. The push-pull stage is operable to generate a buffered output signal on the output responsive to the first and second bootstrapped signals.

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Shanghai, China

Sarah Gao