摘要 |
A novel circuit is coupled to a memory device sense amplifier and a memory device output pin for driving the output pin with data. The circuit includes a first inverter (18) and a second inverter (100) coupled to the first inverter. Transfer gates (30, 104) are coupled across the input and output leads of the first and second inverters, respectively. During a first mode of operation, the first and second transfer gates are closed and the second inverter is three-stated so that the input and output leads of the first and second inverters are held at a voltage between VCC and ground. When it is desired to drive the memory device output pin with data, the first and second transfer gates open, and the second inverter leaves the three-state mode and goes into a low output impedance mode. Because the input and output leads of the first and second inverters are held at a voltage between VCC and ground when the transfer gates are closed, when the transfer gates open, the delay between the time the transfer gates open and the time valid output data appears on the output lead of the second inverter is minimized. The second inverter comprises large transistors and can therefore provide a large output current. However, because the second inverter is three-stated when the second transfer gate is closed, the circuit draws minimal power when the first and second transfer gates are closed.
|