Hot plugging protection
An overcharge protection circuit comprises a first series of first terminals a second series of second terminals, a first overvoltage protection device connected between each consecutive pair of first terminals, a current balancing device connected between each consecutive pair of second terminals, and a second overvoltage protection device connected between a first terminal and a second terminal. The second overvoltage protection device is configured to pass a current if a voltage over the second overvoltage protection device exceeds a threshold. The second overvoltage protection device may comprise a bidirectional ESD diode, while both the first overvoltage protection device and the second overvoltage protection device may comprise a unidirectional ESD diode.
1. An overcharge protection circuit comprising
a first series of first terminals;
a second series of second terminals;
a first overvoltage protection device connected between each consecutive pair of first terminals;
a current balancing device connected between each consecutive pair of second terminals; and
a second overvoltage protection device connected between a first terminal and a second terminal;
wherein the second overvoltage protection device is configured to pass a current if a voltage over the second overvoltage protection device exceeds a threshold.
2. The overcharge protection circuit according to claim 1 , wherein the second overvoltage protection device comprises a bidirectional ESD diode.
3. The overcharge protection circuit according to claim 1 , wherein the first overvoltage protection device comprises a unidirectional ESD diode.
4. The overcharge protection circuit according to claim 1 , wherein the current balancing device comprises an electronic switch.
5. The overcharge protection circuit according to claim 4 , wherein the electronic switch is configured to be controlled by an ESD diode.
6. The overcharge protection circuit according to claim 1 , wherein the first series and the second series comprise equal numbers of terminals.
7. The overcharge protection circuit according to claim 1 , wherein a second overvoltage device is connected between each terminal of the first series and each corresponding terminal of the second series.
8. A battery stack control circuit comprising
a first series of first terminals;
a second series of second terminals;
a first overvoltage protection device connected between each consecutive pair of first terminals;
a current balancing device connected between each consecutive pair of second terminals; and
a second overvoltage protection device connected between a first terminal and a second terminal,
wherein the second overvoltage protection device is configured to pass a current if a voltage over the second overvoltage protection device exceeds a threshold;
wherein the first terminals are configured to measure a voltage of batteries of the battery stack; and
wherein the second terminals are configured to drive a current of batteries of the battery stack.
9. The overcharge protection circuit according to claim 8 , wherein the second overvoltage protection device comprises a bidirectional ESD diode.
10. The overcharge protection circuit according to claim 8 , wherein the first overvoltage protection device comprises a unidirectional ESD diode.
11. The overcharge protection circuit according to claim 8 , wherein the current balancing device comprises an electronic switch.
12. The overcharge protection circuit according to claim 11 , wherein the electronic switch is configured to be controlled by an ESD diode.
13. The overcharge protection circuit according to claim 8 , wherein the first series and the second series each comprise fifteen terminals.
14. An apparatus comprising
a stack of batteries having a set of battery terminals; and
at least one overcharge protection circuit comprising
a first series of first terminals;
a second series of second terminals;
a first overvoltage protection device connected between each consecutive pair of first terminals;
a current balancing device connected between each consecutive pair of second terminals; and
a second overvoltage protection device connected between a first terminal and a second terminal;
wherein the second overvoltage protection device is configured to pass a current if a voltage over the second overvoltage protection device exceeds a threshold; and
wherein each battery terminal is connected to both a first terminal and a corresponding second terminal.
15. The apparatus according to claim 14 , wherein the second overvoltage protection device comprises a bidirectional ESD diode.
16. The apparatus according to claim 14 , wherein the first overvoltage protection device comprises a unidirectional ESD diode.
17. The apparatus according to claim 14 , wherein the second overvoltage protection device comprises an electronic switch configured to be controlled by an ESD diode.
18. The apparatus according to claim 14 , wherein each first terminal is connected to a battery terminal via a resistor.
19. The apparatus according to claim 14 , wherein the first terminals are configured to
measure a voltage of batteries of the battery stack; and
wherein the second terminals are configured to drive a current of batteries of the battery stack.
20. The apparatus according to claim 19 , wherein a lowest voltage battery terminal and a highest voltage battery terminal are connected to a respective second terminal via a resistor.