Samsung Electronics Co., Ltd.

Ho-keun Cho

Byung-Gil Choi

Ki-sung Kim

Jae-Wook Lee

Jong-Chul Park

Soo-Jin Paek

Chang-han Choi

Jong-soo Seo

A phase-change random access memory (PRAM) device includes a plurality of banks, a plurality of column redundancy cell arrays, and a plurality of column redundancy write drivers. Each of the plurality of column redundancy cell arrays corresponds to at least one of the banks. Each of the plurality of column redundancy write drivers corresponds to at least one of the column redundancy cell arrays. The column redundancy write drivers are configured to transmit respective redundancy test data to the corresponding ones of the column redundancy cell arrays in response to a test control signal, which may be activated in response to each program pulse for writing data. Related test and access methods are also discussed.

Methods of operating phase-change random access memory devices

In phase locked loop, a phase detector detects a phase difference between a first clock signal and a second clock signal and output a first output signal based on the detected difference. A charge pump generates a control voltage in response to the first output signal from the phase detector. A voltage-controlled oscillator generates the second clock signal. A controller controls the control voltage such that the phase difference between the first clock signal and the second clock signal is increased in response to a burn-in test mode signal.

Phase locked loops capable of burn-in testing with increased locking range and burn-in testing method thereof

Growing community of inventors

Gyeonggi-do, South Korea

Ho-keun Cho