Abstract: A programmable high speed frequency divider, in which the construction of flip-flops for forming a frequency divider which is capable of programming the dividing ratio of an input clock frequency is simplified in order to increase the operation speed of the frequency divider, is provided. By simplifying the structures of least significant bit flip-flops, including the flip-flop representing the least significant bit, among flip-flops forming a frequency divider, the operation speed of the counter in the frequency divider is increased and the frequency limit of an input clock which can be divided is raised.

Abstract: An apparatus and method for measuring an electrochemical impedance at high speed. The method for measuring the electrochemical impedance of an electrolyte at high speed includes applying a direct current (DC) voltage having the reaction potential of the electrolyte to the electrolyte via a counter electrode and, after a delay, applying a signal voltage, including a DC voltage added to a differentiated or integrated Dirac-delta function voltage, to the electrolyte; computing a digital data value related only to the differentiated or integrated Dirac-delta function voltage, obtained by converting signal current flowing in a working electrode via the electrolyte into a voltage, integrating or differentiating the voltage, and Fourier transforming the result of the integration or differentiation; and obtaining changes in magnitude and phase as a function of frequency based on the Fourier transform, to compute the impedance.

Abstract: A current-mode bidirectional input/output buffer circuit for impedance matching and operation at a high speed. The current-mode bidirectional input/output buffer circuit communicates with an external chip having the same current-mode bidirectional input/output buffer. In the buffer, a transmitting-receiving average voltage output unit converts an average current value between a transmission signal to be transmitted to the external chip and a receiving signal transmitted from the external chip, into an average voltage. A reference voltage output unit converts a reference current value selectively generated according to a voltage level of the transmission signal, into a reference voltage. A comparator compares the voltage from the transmitting-receiving average voltage output unit to the voltage from the reference voltage output unit to provide a logic signal corresponding to the received signal transmitted from the external chip.