A buffer includes a pull-down means, a pull-up means, and a control signal generator. The pull-down means generates an output signal that transitions to a first state at a relatively high speed when an input signal transitions from a first state to a second state in response to a control signal at a first control state. The pull-up means generates an output signal that transitions to the second state at a relatively high speed when an input signal transitions from the second state to the first state in response to a control signal of a second control state. The control signal generator produces the control signal as a function of the output signal. Accordingly, the buffer can transfer an input signal at a high speed in both cases of a high-to-low transition of the input signal as well as a low-to-high transition of the input signal.
A driver circuit that outputs a data signal uses feedback of the data signal to the driver circuit to modulate a drive strength of the driver circuit. The driver circuit has a pull-up driver stage and a pull-down driver stage. The pull-up driver stage uses a pull-up control circuit to modulate a drive strength of the pull-up driver stage dependent on a voltage of the data signal. The pull-down driver stage uses a pull-down control circuit to modulate a drive strength of the pull-down driver stage dependent on the voltage of the data signal.
A driver structure for an I/O buffer circuit is disclosed. The driver structure includes a pre-push-pull driver and a post-push-pull driver. A delay circuit along is connected in series between the input signals of the pre-push-pull driver and the post-push-pull driver. After a delay time following a transition of the input signal, the circuit operation of the post-push-pull driver is turned off before the amplitude of the output signal reaches its maximum overshooting. This changes the output conductivity to inhibit the overshooting in the output signal, preventing power bounce and ground bounce at the receiving end.
