IGNITION CONTROL SYSTEM FOR A HIGH-VOLTAGE BATTERY SYSTEM

1 . A circuit, comprising:

a switch circuit configured to be electrically connected to an ignition circuit;

a high-side path control circuit electrically connected between the switch circuit and a battery terminal;

a low-side path control circuit electrically connected between the switch circuit and a ground terminal; and

a control circuit configured to detect an abnormal condition associated with the ignition circuit, the control circuit configured to activate the high-side path control circuit in response to the detected abnormal condition.

2 . The circuit of claim 1 , wherein the high-side path control circuit defines a looped path including the switch circuit, the battery terminal, and terminals configured to be electrically connected with the ignition circuit when the high-side path control circuit is activated and the low-side path control circuit is deactivated.

3 . The circuit of claim 1 , wherein the low-side path control circuit defines a grounded path including the switch circuit, the ground terminal, terminals configured to be electrically connected with ignition circuit when the low-side path control circuit is activated and the high-side path control circuit is deactivated.

4 . The circuit of claim 1 , wherein the abnormal condition is detected in response to at least one of a current limit through the ignition circuit being exceeded or a dwell-time limit being exceeded.

5 . The circuit of claim 1 , wherein the high-side path control circuit is activated as part of a soft shutdown protection mode.

6 . The circuit of claim 1 , wherein the high-side path control circuit is activated as part of a current limit protection mode.

7 . The circuit of claim 1 , wherein the control circuit is configured to trigger activation, at a frequency, the high-side path control circuit to limit current through the ignition circuit in response to the detected abnormal condition and based on feedback associated with a primary current through the ignition circuit.

8 . The circuit of claim 1 , wherein the control circuit is configured to trigger switching, at a pre-defined frequency, between the high-side path control circuit and the low-side control circuit to limit current in response to the detected abnormal condition.

9 . The circuit of claim 1 , wherein the control circuit is configured to trigger oscillating activation between the high-side path control circuit and the low-side path control circuit to limit current through the ignition circuit in response to the detected abnormal condition.

10 . The circuit of claim 1 , wherein the high-side path control circuit includes a first transistor, and the low-side path control circuit includes a second transistor.

11 . The circuit of claim 1 , wherein the ignition circuit includes an ignition coil and the switch circuit includes an insulated-gate bipolar transistor (IGBT) device.

12 . A circuit, comprising:

a switch circuit configured to be electrically connected to an ignition circuit;

a high-side path control circuit electrically connected between the switch circuit and a battery terminal;

a low-side path control circuit electrically connected between the switch circuit and a ground terminal; and

a control circuit configured to detect an over dwell-time condition associated with the ignition circuit, the control circuit configured to deactivate the low-side path control circuit in response to the over dwell-time condition such that energy from the ignition circuit is dissipated via the switch circuit.

13 . The circuit of claim 12 , wherein the control circuit is configured to activate the high-side control circuit in response to the detection of the over dwell-time condition.

14 . The circuit of claim 12 , wherein the control circuit is configured to deactivate the high-side control circuit in response to the detection of the over dwell-time condition.

15 . The circuit of claim 12 , wherein the switch circuit includes an IGBT device, the IGBT device is operated in linear mode by the control circuit in response to the detection of the over dwell-time condition.

16 . A circuit, comprising:

a switch circuit configured to be electrically connected to an ignition circuit;

a high-side path control circuit defining a looped path including the switch circuit, the battery terminal, and terminals configured to be electrically connected with the ignition circuit when the high-side path control circuit is activated;

a low-side path control circuit defining a grounded path including the switch circuit, a first ignition circuit terminal, a second ignition circuit terminal, and a ground terminal, when the low-side path control circuit is activated,

the first ignition circuit terminal and the second ignition circuit terminal configured to be electrically connected with ignition circuit; and

a control circuit configured to detect an over-current condition associated with the ignition circuit, the control circuit configured to trigger oscillation between the looped path and the grounded path in response to the detected over-current condition.

17 . The circuit of claim 16 , wherein the high-side path control circuit defines a looped path including the switch circuit, the battery terminal, and terminals configured to be electrically connected with the ignition circuit when the high-side path control circuit is activated and the low-side path control circuit is deactivated.

18 . The circuit of claim 16 , wherein the low-side path control circuit defines a grounded path including the switch circuit, the ground terminal, terminals configured to be electrically connected with ignition circuit when the low-side path control circuit is activated and the high-side path control circuit is deactivated.

19 . The circuit of claim 16 , wherein the low-side path control circuit is deactivated when the looped path is defined.

20 . The circuit of claim 16 , wherein the high-side path control circuit is deactivated when the ground path is defined.