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US 6,646,481 B2Granted
Current steering circuit for amplifier
AssigneeWinbond Electronics Corp.
InventorsTim Blankenship, Stephen Bily
Life of this patent
Estimating the term…
Abstract
Improved techniques for controlling current flow in an amplifier circuit provide steering of analog outputs of digital to analog converters and a full range of voltage output without necessitating a full range amplifier configuration and can be realized in a small space on an IC chip.
Claims10
A current steering circuit comprising:
- a current input node coupled to a first circuit path, the first circuit path drawing current from the current input node during a first mode of operation;
- a comparator coupled to the current input node, the comparator drawing negligible amount of current from the current input node during the first mode of operation, the comparator drawing significant amount of current from the current input node during a second mode of operation so as to divert current from the first circuit path;
- and
- a current mirror coupled to the comparator, the current mirror maintaining current flow through a second circuit path during the second mode of operation but not during the first mode of operation.
1 more element
A current steering circuit comprising:
- a current input node coupled to a first circuit path, the first circuit path drawing current from the current input node during a first mode of operation;
- a first transistor coupled to the current input node, the first transistor drawing negligible current from the current input node during the first mode of operation, the first transistor drawing current from the current input node during a second mode of operation to divert current from the first circuit path;
- a second transistor coupled to receive the current drawn by the first transistor from the current input node during the second mode of operation, the second transistor forming a current mirror with a third transistor that is coupled to a second circuit path;
- a reference node providing a reference voltage to a fourth transistor;
- a fifth transistor forming a current mirror with the fourth transistor, the fifth transistor supplying a reference current to the first transistor, the amount of the reference current being related to the reference voltage;
- and wherein the current steering circuit is placed in the first mode of operation or the second mode of operation depending on a voltage level on a voltage input node relative to the reference voltage.
3 more elements
Dependencies are inferred from the claim text.