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US 5,686,822 AGranted
Method of making a reference current generator
AssigneeHarris Corporation
InventorsGregg Douglas Croft, Sang-Gug Lee, Steven Robert Jost
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AssigneeHarris Corporation
InventorsGregg Douglas Croft, Sang-Gug Lee, Steven Robert Jost
Estimating the term…
A current generator and method of making a current generator in which two resistors are provided, each in series with one of two transistors in the generator, and in which one of the resistors is trimmed if the reference current is too large and the other is trimmed if the reference current is too small, thereby obviating the problems of the prior art in which one resistor must be trimmed by a potentially large and unacceptable amount. The two resistors are formed with a distribution of resistances which is centered on their corresponding target resistance values so that the number of resistors to be trimmed and the amount of trimming per resistor are reduced. The appropriate target resistances of the resistors can be determined if a maximum trim factor is set. The method is insensitive to variations in the process by which the resistances of the resistors are initially set and reduces the variability of the untrimmed reference current with respect to resistor critical dimensions.
A method of making a current generator for providing a reference current which is within a target range, the current generator having two pairs of transistors connected to provide the reference current and two trimmable resistors, a first of the resistors being connected in series between a DC potential and a first transistor of a first of the two pairs, and a second of the resistors being connected in series between the DC potential and a second transistor of the first pair comprising the steps of:
A method of making first and second resistors for a current generator which provides a reference current within a target range, the method being generally insensitive to variations in a process for initially setting resistances of the resistors and comprising the steps of:
A method of setting resistances of resistors in a current generator comprising the steps of:
A reference current generator for providing a reference current, comprising:
A method of providing a constant current source within a desired range of current values for use as a reference current in one or more additional circuits, the method comprising:
A source of a constant value reference current within a desired range of current values comprising:
A reference current source comprising:
Dependencies are inferred from the claim text.