DRAM circuit and its sub-word line driver

A dynamic random access memory (DRAM) circuit and its associated sub-word-line driver. The DRAM circuit includes a boost circuit, a main word line driver and a sub-word line driver. The boost circuit changes its output boost voltage, which lies between an internal supply voltage and an operating voltage, according to an input row access strobe (RAS) signal. The main word line driver is connected to the output terminal of the boost circuit and the main word line, selected according to input address decoding, is driven by the boost voltage. The sub-word line driver is connected to the main word line. An even or odd sub-word-line signal is generated according to the least significant bit of an input address so that voltage level on the main word line can be used to drive the corresponding sub-word line.