Precision current sensing

A current tracking sense system comprising:

• a power stage that receives a current input and a control signal as input and comprises:
• a power transistor, wherein a base of the power transistor receives the control signal, a terminal of the power transistor receives the current input, and a terminal of the power transistor is input to a voltage regulation loop configured to regulate the power stage;
• and
• a sense transistor, wherein the sense transistor acts as the current mirror and mirrors the current flowing in the power transistor, wherein a base of the sense transistor is coupled to the base of the power transistor, a terminal of the sense transistor receives the current input, and a terminal of the sense transistor is input to the voltage regulation loop;
• and
• a programmable sub-circuit coupled to the power stage that is configured to adjust a value of a mirror ratio of the power stage;
• wherein:
• the programmable sub-circuit further comprises one or more Zener zap diodes configured to operate in one of an open state or a closed state, wherein the value of the mirror ratio depends on the state of the one or more Zener zap diodes,
• the one or more Zener zap diodes comprise a first Zener zap diode, a second Zener zap diode, and a third Zener zap diode,
• the first Zener zap diode and the second Zener zap diode are coupled to a terminal of the power transistor,
• the third Zener zap diode is coupled to a terminal of the sense transistor, and
• as compared to the mirror ratio when operating in the open state, the first Zener zap diode and the second Zener zap diode increase the mirror ratio when operating in the closed state and the third Zener zap diode decreases the mirror ratio when operating in the closed state.

A method, comprising:

• performing current mirroring using a current mirror comprising a sense device, wherein a mirror ratio of the current mirror is based on a programmable sub-circuit, wherein the mirror ratio of the current mirror is based on the programmable sub-circuit and is further based on one or more Zener zap diodes of the programmable sub-circuit coupled to the sense device and a power device coupled to the sense device;
• maintaining, by a voltage regulation loop, a collector potential of the sense device within a threshold difference level of a collector potential of the power device, wherein the sense device mirrors a current flowing in the power device;
• wherein the one or more Zener zap diodes further comprises one or more of:
• a first shorted Zener zap diode, wherein the first shorted Zener zap diode increases the mirror ratio;
• and
• a second shorted Zener zap diode, wherein the second shorted Zener zap diode decreases the mirror ratio.