Voltage threshold sensing systems and related methods
Implementations of voltage sensing systems may include: a high side current mirror coupled to a reference current source coupled to at least one diode. The at least one diode may be coupled to a resistor and to a comparator. The resistor may be coupled to the ground. The comparator may be coupled with a reference voltage. The comparator may be configured to receive a comparison voltage from the diode and output whether the comparison voltage is higher or lower than the reference voltage.
1. A voltage sensing system comprising:
a first high side current mirror comprising a first transistor and a second transistor, the first high side current mirror coupled to a first reference current;
a second high side current mirror comprising a third transistor and a fourth transistor, the second high side current mirror coupled to a second reference current;
a fifth transistor coupled between the second high side current mirror and the comparator;
at least one diode coupled between the first high side current mirror and the second high side current mirror, the at least one diode coupled to a comparator;
wherein the first high side current, the second high side current, and the at least one diode are coupled to ground;
wherein a current passed by the second transistor is greater than a current passed by the fourth transistor; and
wherein the comparator is coupled with a reference voltage and configured to receive a comparison voltage from the at least one diode and output whether the comparison voltage is one of higher and lower than the reference voltage.
2. The system of claim 1 , wherein the fifth transistor is an n-channel metal-oxide-semiconductor field-effect (NMOS) transistor.
3. The system of claim 1 , wherein the at least one diode is a Zener diode.
4. The system of claim 1 , wherein a gate of the first transistor and a gate of the second transistor are coupled to a drain of one of the first transistor and the second transistor.
5. The system of claim 1 , wherein a gate of the third transistor and a gate of the fourth transistor are coupled to a drain of one of the third transistor and the fourth transistor.
6. The system of claim 1 , wherein the first current mirror and the second current mirror further comprise two PMOS transistors coupled together.
7. The system of claim 1 , wherein the gate of the fifth transistor is coupled to the output of the fifth transistor.
8. A voltage threshold sensing system comprising:
two p-channel metal-oxide-semiconductor field-effect (PMOS) transistors coupled together, the gates of the two PMOS transistors coupled to the drain of a first one of the two PMOS transistors, the drain of the first one of the two PMOS transistors coupled with a constant current source, and a drain of a second one of the two PMOS transistors coupled to a diode;
wherein the diode is coupled with a high impedance input of a comparator and to a resistor coupled to ground; and
wherein the comparator is configured to determine whether a supply voltage coupled to the second one of the two PMOS transistors is one of above and below a reference voltage coupled to another high impedance input of the comparator.
9. The system of claim 8 , wherein the diode is a Zener diode.
10. The system of claim 8 , further comprising a second comparator coupled with a second reference voltage and configured to receive a second comparison voltage from the diode and output whether the comparison voltage is one of higher and lower than the reference voltage.