Electronic fuse circuit and fuse circuitry

Abstract

The electronic fuse circuit disclosed herein includes a fuse switch and a current control circuit. The fuse switch is coupled to a main control node and generates an output current. The current control circuit is coupled to the main control node and includes a switch, a switch control circuit, and a control enable circuit. The switch is coupled to the main control node and a sub-control node and generates a sink current to adjust the voltage level of the main control node downwards. The switch control circuit is coupled to the sub-control node and controls the switch based on the output current, average current voltage, and temperature-dependent voltage. The control enable circuit is coupled to the sub-control node and enables the switch control circuit to control the switch when at least one of a plurality of preset conditions is met. The plurality of preset conditions include the output current exceeding a current threshold and the fuse switch junction temperature exceeding a temperature threshold.

Claims

1. An electronic fuse circuit, comprising: a fuse switch coupled to a main control node for generating an output current and an output voltage based on an input voltage, and for adjusting the output current and the output voltage based on a voltage level of the main control node; and a current control circuit coupled to the main control node, comprising: a first switch coupled to the main control node and a first sub-control node for generating a first sink current, and for adjusting the first sink current based on a voltage level of the first sub-control node, wherein the first sink current flows out from the main control node and is used to adjust the voltage level of the main control node downwards; A first switch control circuit, coupled to the first sub-control node, is configured to adjust the voltage level of the first sub-control node based on the output current, an average current voltage, and a temperature-dependent voltage, wherein the average current voltage is associated with an average of the output current of the electronic fuse circuit and at least another output current of at least another electronic fuse circuit; and a control enable circuit, coupled to the first sub-control node, is configured to enable the first switch control circuit to adjust the voltage level of the first sub-control node in response to at least one of a plurality of preset conditions being met when the output voltage exceeds a start-up voltage level, wherein the preset conditions include the output current exceeding a current threshold and a junction temperature of the fuse switch exceeding a temperature threshold, and the temperature-dependent voltage is associated with the junction temperature of the fuse switch.

2. The electronic fuse circuit as claimed in claim 1, wherein the first switch control circuit comprises: a current generating circuit for generating a first temperature-dependent current based on the temperature-dependent voltage; a current mirror circuit coupled to the current generating circuit and a first reference node for replicating the first temperature-dependent current to generate a second temperature-dependent current to the first reference node; and a buffer circuit coupled to a second reference node for buffering the average current voltage to generate a buffered average current voltage at the second reference node. A differential voltage generating circuit, coupled to the current mirror circuit and the buffer circuit respectively to the first reference node and the second reference node, is used to generate a temperature-dependent voltage difference based on the second temperature-dependent current, so that a reference voltage is generated at the first reference node, wherein the reference voltage is the temperature-dependent voltage difference plus the buffered average current voltage; and an amplifier circuit, coupled to the first sub-control node and the first reference node, is used to adjust the voltage level of the first sub-control node with a first switch control signal based on the reference voltage and a first difference between a current sensing voltage associated with the output current.

3. The electronic fuse circuit as claimed in claim 1, wherein the control enable circuit comprises: a first indication circuit for generating a second indication signal based on a first indication signal, wherein the first indication signal indicates the state of a soft-start operation of the electronic fuse circuit; a second indication circuit for generating a third indication signal based on a current limiting voltage and a current sensing voltage associated with the output current, wherein the third indication signal indicates the state of the output current, the current threshold corresponding to α1 times the current limiting voltage, and α1 being between 0 and 1; and a third indication circuit for generating a fourth indication signal based on a temperature monitoring voltage and a temperature-dependent voltage, wherein the fourth indication signal indicates the junction temperature of the fuse switch, and the temperature threshold corresponding to the temperature monitoring voltage plus a preset voltage difference. A sub-switch control circuit, coupled to the first indicator circuit, the second indicator circuit and the third indicator circuit, and used to generate a sub-switch control signal according to the second indicator signal, the third indicator signal and the fourth indicator signal; and a sub-switch, coupled to the sub-switch control circuit and the first sub-control node, and used to turn on or off according to the sub-switch control signal.

4. The electronic fuse circuit as described in claim 1, further comprising: a soft-start circuit coupled to the main control node, for controlling the output voltage to increase according to a fixed rising slope of a soft-start voltage when the output voltage does not reach a working voltage level, and for outputting an indication signal to the control enable circuit of the current control circuit according to a voltage level of the output voltage, wherein the indication signal is used to indicate the relationship between the output voltage and the start-up voltage level, and the working voltage level is greater than the start-up voltage level; wherein the control enable circuit is used to switch the voltage level of the first sub-control node to a disable voltage level when the output voltage is lower than the start-up voltage level, thereby turning off the first switch.

5. The electronic fuse circuit as claimed in claim 1, further comprising: a current limiting circuit coupled to the main control node, for controlling the output current to not exceed a first current limit value when the output voltage is lower than the start-up voltage level, and for controlling the output current to not exceed a second current limit value when the output voltage exceeds the start-up voltage level, wherein the second current limit value is greater than the first current limit value.

6. The electronic fuse circuit as claimed in claim 1, further comprising: a current sensing circuit coupled to the main control node and the fuse switch, for detecting the output current to output a first sensing current and a second sensing current, wherein the first sensing current is used to generate the average current voltage, the second sensing current is used to generate a current sensing voltage associated with the output current, and a current level of the first sensing current and a current level of the second sensing current are both 1 / M times a current level of the output current, where M can be a positive number greater than 0.

7. The electronic fuse circuit as claimed in claim 1, further comprising: a temperature alarm circuit adjacent to the fuse switch and coupled to the current control circuit, for detecting the junction temperature of the fuse switch, for generating a temperature-dependent voltage and a temperature-dependent current based on the junction temperature, and for providing one of the temperature-dependent voltage and the temperature-dependent current when the output voltage exceeds the activation voltage level, thereby generating a temperature monitoring voltage, wherein the temperature monitoring voltage is associated with the junction temperature of the fuse switch, or is associated with an average of the junction temperature of the fuse switch and a junction temperature of at least one other fuse switch of the at least one other electronic fuse circuit.

8. A fuse circuit system, comprising: a first electronic fuse circuit having a first input pin, a first output pin, and a first temperature monitoring pin; and a second electronic fuse circuit connected in parallel with the first electronic fuse circuit, having a second input pin, a second output pin, and a second temperature monitoring pin; wherein the first input pin and the second input pin are commonly coupled to a first node, and the first output pin and the second output pin are commonly coupled to a second node, and each of the first and second electronic fuse circuits comprises: a fuse switch coupled to a main control node, for receiving an input voltage from the first node, for generating an output current based on the input voltage, for generating an output voltage at the second node based on the input voltage, and for adjusting the output current and the output voltage based on a voltage level of the main control node; and a current control circuit coupled to the main control node, comprising: A first switch, coupled to the main control node and a first sub-control node, is used to generate a first sink current and to adjust the first sink current according to a voltage level of the first sub-control node, wherein the first sink current flows out from the main control node and is used to adjust the voltage level of the main control node downward. A first switch control circuit, coupled to the first sub-control node, is configured to adjust the voltage level of the first sub-control node based on the output current, an average current voltage, and a temperature-dependent voltage, wherein the average current voltage is associated with an average of the output current of the first electronic fuse circuit and the output current of the second electronic fuse circuit; and a control enable circuit, coupled to the first sub-control node, is configured to enable the first switch control circuit to adjust the voltage level of the first sub-control node in response to at least one of a plurality of preset conditions being met when the output voltage exceeds a start-up voltage level, wherein the preset conditions include the output current exceeding a current threshold and a junction temperature of the fuse switch exceeding a temperature threshold, and the temperature-dependent voltage is associated with the junction temperature of the fuse switch.

9. The fuse circuit system as claimed in claim 8, wherein the first temperature monitoring pin and the second temperature monitoring pin are jointly coupled to a third node, the fuse circuit system further comprising: a first resistor coupled to the third node and a ground voltage; and a second resistor coupled to the third node and the ground voltage.

10. The fuse circuit system as claimed in claim 8, further comprising: a first resistor coupled to the first temperature monitoring pin and a power supply voltage; and a second resistor coupled to the second temperature monitoring pin and the power supply voltage.

Images