Bicmos sense circuit for sensing data during a read cycle of a memory

Abstract

A bipolar complementary metal oxide semiconductor (BICMOS) sense circuit for sensing data on read data lines during a read cycle of a memory comprises a load portion and a sense amplifier portion. In one form, the load portion couples true and complement read data lines to a first voltage in response to a start of a read cycle. When the true and complement read data lines exceed a predetermined voltage, the sense amplifier is enabled. The load portion becomes inactive when the voltage on the read data lines reaches approximately the first voltage. Then a selected memory cell provides a differential voltage on a bit line pair, which is coupled to the read data lines, indicating the contents of the selected memory cell. The sense amplifier provides a differential current onto a corresponding read global data line pair in response to the differential voltage. At the termination of the read cycle, the load portion becomes active again and couples the read data lines to a second voltage to disable the sense amplifier. The predetermined voltage is between the first voltage and the second voltage. The circuit increases the speed of the sensing function over a CMOS design, while keeping power consumption to a minimum. In another form, the sense circuit generates a read sense voltage that is substantially independent of non-tracking process variations between P-channel and N-channel field-effect transistors.