Hot-swap protection circuit
View Patent ↗Embodiments of the present invention provide methods and circuitry for protecting a circuit during hot-swap events. Hot swap protection circuitry includes as overcurrent detection circuit which decouples power from a load. Circuitry is provided to detect ground-fault conditions. Noise detection circuitry is provided to reduce noise in the power that is delivered to the load.
1. An electronic device comprising:
first electronic circuitry; and
a protection circuit in electrical communication with the first electronic circuitry, said protection circuit comprising:
a switch coupled to said first electronic circuitry and configured to couple said first electronic circuitry with a source of power;
a first detector configured to detect power from said source of power, said first detector operatively coupled with said switch, wherein said switch closes responsive to said first detector;
a second detector configured to detect noise in said power, wherein said switch opens responsive to said second detector;
a positive terminal; and
a negative terminal,
wherein said switch is a transistor device having a gate terminal, a source terminal, and a drain terminal,
said second detector comprising:
a bias voltage source; and
an operational amplifier having:
an inverting input coupled to a positive voltage potential of said source of power and coupled with said bias voltage source;
a non-inverting input coupled with a negative voltage potential of said source of power; and
an output coupled to said gate terminal of said switch,
wherein said bias voltage source is coupled with said first detector.
2. The electronic device of claim 1 wherein said output of said operational amplifier is further coupled with said first detector.
3. The electronic device of claim 1 wherein said bias voltage source is a voltage divider.
4. The electronic device of claim 1 wherein said switch closes at a slower rate than it opens.
5. The electronic device of claim 1 wherein said switch is characterized by having a variable conductance, wherein said switch closes at a slow rate such that its conductance is gradually increased.
6. The electronic device of claim 1 wherein said transistor is an FET transistor.