Patent ID: 11946973
Assignee: TEXAS INSTRUMENTS INCORPORATED
Field: Measurement (Instruments)
Classification: CPC G  H | IPC G

Claim 10:
11. A system, comprising:
a scan flip-flop that includes a functional data input, a clock input, a scan data input, a scan enable input, and an output, wherein the scan flip-flop also includes:
a first transistor and a second transistor coupled to the functional data input, wherein the functional data input is configured to receive a data signal;
a third transistor coupled to the clock input and a fourth transistor coupled to an inverse clock input, wherein the clock input is configured to receive a clock signal, and the inverse clock input is configured to receive an inverse of the clock signal;
a fifth transistor coupled to the scan enable input and the first transistor;
a sixth transistor coupled to an inverse scan enable input and the second transistor; and
an input multiplexer that includes the first transistor, second transistor, fifth transistor, and sixth transistor, and also includes a seventh transistor coupled to the scan data input, an eighth transistor coupled to the scan data input, a ninth transistor coupled to the scan enable input, and a tenth transistor coupled to the inverse scan enable input, wherein the input multiplexer is configured to select between the functional data input and the scan data input, and wherein the input multiplexer also includes:
a first diode-connected transistor coupled between a first voltage rail and the seventh transistor, wherein the first diode-connected transistor is configured to provide a first voltage to a source terminal of the seventh transistor, wherein the first voltage is less than a first supply voltage; and
a second diode-connected transistor coupled between a second voltage rail and the eighth transistor, wherein the second diode-connected transistor is configured to provide a second voltage to a source terminal of the eighth transistor, wherein the second voltage is greater than a second supply voltage.