US 4,567,378 AGranted

Driver circuit for controlling signal rise and fall in field effect transistor processors

AssigneeInternational Business Machines Corporation

InventorNorman Raver

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Abstract

An off-chip driver (OCD) circuit is described including a first output device and a second output device having a common output connection wherein a rising (1 bit) or falling (0 bit) signal is applied through an input circuit 24 to the output devices. The output signal which appears at the common output connection will exhibit a rise time and a fall time corresponding to the rise and fall of the input signal. A first monitoring device is connected to the output signal to monitor the rise time of the output signal and a second monitoring device is connected to the output signal to monitor the fall time of the output signal. A ramp generator is provided which generates a reference signal which also includes a rise time and a fall time. The two monitor circuits and compare the rise and fall times of the output signal with the reference rise time and reference fall time to produce a feedback signal to control the rise and fall times of the output signal in accordance with the reference signal.

Claims4

Dependent claims

A driver circuit for providing an output signal having a rise time adjusted in accordance with a rise time of a standard ramp signal comprising:

an input circuit responsive to an input signal of the type having a rising level, said input circuit providing a corresponding rising signal on an output lead therefrom,
an output circuit including at least one output device having an output connection, said at least one output device being connected to said output lead of said input circuit and responsive to said corresponding rising signal of said input circuit,
a ramp generator circuit connected to said output lead of said input circuit for providing an output signal having a desired rise time in response to said corresponding rising signal on said input circuit output lead,
a monitor circuit connected to said output connection of said at least one output device and to said ramp generator and responsive to said signals thereon to provide a feedback signal to said at least one output device when said output signal rises faster or slower than said ramp signal, said feedback signal adjusting said output signal in accordance with the rise time of said ramp signal.

1 more element

Dependencies are inferred from the claim text.