Apparatus and method for comparing input current to set of current thresholds

An apparatus, comprising:

• a first comparator having a first input to receive an input signal, a second input to receive a reference signal, and an output;
• a current source to provide a first threshold current;
• a first current sink to provide a second threshold current;
• a second current sink to provide a third threshold current;
• a set of one or more switches coupled between the current source and the first and the second current sinks, the set of one or more switches having an input coupled to the output of the first comparator;
• and
• a second comparator to compare the input signal against a difference between the second and first threshold currents.

An apparatus, comprising:

• a first comparator having a first input to receive an input signal, a second input to receive a reference signal, and an output;
• a current source to provide a first threshold current;
• a first current sink to provide a second threshold current;
• a second current sink to provide a third threshold current;
• a set of one or more switches coupled between the current source and the first and the second current sinks, the set of one or more switches having an input coupled to the output of the first comparator;
• and
• a second comparator configured to compare the input signal against a sum of the first and second threshold currents.

An apparatus, comprising:

• a current source;
• a first switching device;
• a second switching device;
• a first current sink, wherein the current source, the first switching device, the second switching device, and the first current sink are coupled in series between first and second voltage rails;
• a first comparator including a first input coupled to a node between the current source and the first switching device, and a second input to receive a reference signal;
• a second comparator including a first input coupled to a node between the second switching device and the first current sink, and a second input to receive the reference signal;
• and
• a third comparator including a first input to receive an input signal and coupled to a node between the first and second switching devices, a second input to receive the reference signal, and an output coupled to control inputs of the first and second switching devices.