Abstract: A low power high-speed bus receiver which receives a pair of differential signals to obtain the corresponding logic value is provided. The bus receiver includes a differential amplifier, a pair of input switches and a pair of power switches. The differential amplifier has a pair of input terminals and a pair of power terminals. The pair of input switches are respectively connected between the pair of input terminals of the differential amplifier and the pair of differential signals. The pair of input switches are turned on for a predetermined time period to transmit the pair of differential signals to the differential amplifier. The pair of power switches are respectively connected between the pair of power terminals of the differential amplifier and a pair of external power supplies.

Abstract: A power down system for regulated internal power supply in DRAM comprises a RAS control module, self-refresh clock control circuit, and a power down control circuit. The RAS control module responds with row address strobe signals to output a first power down control signal. While all the row address strobe signals, which denote states of the memory banks, are in a first condition of inactivity, the first power down control signal will inform the power down system to turn off a regulator in the DRAM under the first condition. The self-refresh clock control circuit responds with a self-refresh clock to output a second power down control signal. While the self-refresh clock is in a second condition of non-self-refresh mode, the second power down control signal will inform the power down system to turn off the regulator under the second condition.

Abstract: A device for generating a variable duty cycle clock is provided, which includes a frequency divider, a plurality of first M-stage delay elements, a plurality of second M-stage delay elements, a selector and a logic gate, where M is an integer. The frequency divider divides an input clock to obtain a divided clock. The first M-stage delay elements, which are connected in series, sequentially delay the divided clock for a first delay time to obtain M first delay clocks. The second M-stage delay elements, which are also connected in series and are corresponding to the first M-stage delay elements, sequentially delay the divided clock for a second delay time to obtain M second delay clocks. The second delay time is in a variable proportion to the first delay time. The selector compares the divided clock and each of the M first delay clocks to obtain M state signals.

Abstract: A power down scheme for a regulated sense amplifier power in DRAM. The power-supply level voltage Vccsa of a sense amplifier is turned on only within a certain time duration, which has no relationship with the word line turn-on time. The power down scheme includes control logic gates and time delay circuits which can be triggered by two internal control signals from other control modules in order to generate a power-down control signal for the bit line sense amplifier.