System and method for temperature compensated ESD protection
In accordance with an embodiment, a method for electrostatic discharge (ESD) protection includes: dividing a voltage between a plurality of circuit nodes using a voltage divider circuit to form a divided voltage; compensating a temperature dependency of the divided voltage to form a temperature compensated divided voltage; monitoring the voltage between the plurality of circuit nodes using a transient detection circuit to form a transient detection signal; and activating a clamp circuit coupled between the plurality of circuit nodes based on the temperature compensated divided voltage and based on the transient detection signal.
1. A method for electrostatic discharge (ESD) protection, the method comprising:
dividing a voltage between a plurality of circuit nodes using a voltage divider circuit to form a divided voltage;
compensating a temperature dependency of the divided voltage to form a temperature compensated divided voltage;
monitoring the voltage between the plurality of circuit nodes using a transient detection circuit to form a transient detection signal; and
activating a clamp circuit coupled between the plurality of circuit nodes based on the temperature compensated divided voltage and based on the transient detection signal.
2. The method of claim 1 , further comprising amplifying the temperature compensated divided voltage and providing the amplified temperature compensated divided voltage to an input node of the clamp circuit.
3. The method of claim 2 , further comprising amplifying the transient detection signal and providing the amplified transient detection signal to the clamp circuit.
4. The method of claim 2 , further comprising providing the transient detection signal to the voltage divider circuit.
5. The method of claim 2 , further comprising amplifying the transient detection signal, and providing the amplified transient detection signal to the voltage divider circuit.
6. The method of claim 1 , wherein temperature compensating the voltage divider circuit comprises providing a temperature dependent current to a node of the voltage divider circuit.
7. The method of claim 1 , wherein the voltage divider circuit comprises a plurality of diode circuits coupled in series with a resistor.
8. The method of claim 7 , wherein:
each diode circuit of the plurality of diode circuits comprises a diode connected transistor; and
temperature compensating the voltage divider circuit comprises using a temperature compensation circuit comprising a transistor having a load path coupled between a node of the voltage divider circuit and one of the plurality of circuit nodes, and a resistor network coupled between the node of the voltage divider circuit and a control node of the transistor.
9. The method of claim 1 , wherein the transient detection circuit comprises an RC circuit.
10. An electrostatic discharge (ESD) circuit comprising:
a voltage divider circuit coupled between a first circuit node and a second circuit node;
a temperature compensation circuit coupled to the voltage divider circuit;
a transient detection circuit coupled to at least one of the first circuit node or the second circuit node; and
a clamp circuit having a load path coupled between the first circuit node and the second circuit node, and a control node coupled to an output of the voltage divider circuit and to an output of the transient detection circuit.
11. The ESD circuit of claim 10 , further comprising a first amplifier coupled between the output of the voltage divider circuit and the control node of the clamp circuit.
12. The ESD circuit of claim 11 , further comprising a second amplifier coupled between the output of the transient detection circuit and the control node of the clamp circuit.
13. The ESD circuit of claim 11 , further comprising a second amplifier coupled between the output of the transient detection circuit and the voltage divider circuit.
14. The ESD circuit of claim 11 , wherein the first amplifier comprises an inverter.
15. The ESD circuit of claim 10 , wherein:
the voltage divider circuit comprises a plurality of diode circuits coupled in series with a resistor; and
the temperature compensation circuit is configured to provide a temperature dependent current.
16. The ESD circuit of claim 15 , wherein:
each of the plurality of diode circuits comprises a diode connected transistor; and
the temperature compensation circuit comprises a transistor having a load path coupled between a node of the voltage divider circuit and one of first circuit node or the second circuit node, and a resistor network coupled between the node of the voltage divider circuit and a control node of the transistor.
17. The ESD circuit of claim 15 , wherein the temperature compensation circuit comprises a plurality of temperature compensation circuits.
18. The ESD circuit of claim 10 , wherein the first circuit node is a power supply node, and the second circuit node is a ground node.
19. The ESD circuit of claim 10 , wherein the transient detection circuit comprises an RC circuit coupled to at least one of the first circuit node or the second circuit node.
20. An integrated circuit comprising:
a plurality of diode connected transistors and at least one resistor disposed on a semiconductor substrate, the plurality of diode connected transistors and the at least one resistor coupled in series between a first power supply connection and a second power supply connection;
a temperature compensation circuit disposed on the semiconductor substrate, the temperature compensation circuit coupled to the plurality of diode connected transistors and the at least one resistor;
a filter resistor and a filter capacitor disposed on the semiconductor substrate, the filter resistor and the filter capacitor coupled in series between the first power supply connection and the second power supply connection;
a clamping transistor disposed on the semiconductor substrate, the clamping transistor having a load path connected between the first power supply connection and the second power supply connection;
a first amplifier disposed on the semiconductor substrate, the first amplifier coupled between the plurality of diode connected transistors and a control node of the clamping transistor; and
a second amplifier disposed on the semiconductor substrate, the second amplifier coupled between the filter capacitor and the control node of the clamping transistor.
21. The integrated circuit of claim 20 , wherein:
each of the plurality of diode connected transistors comprises a diode connected MOS transistor; and
the clamping transistor comprises a MOS transistor.
22. The integrated circuit of claim 21 , wherein: the temperature compensation circuit comprises:
a first MOS transistor having a first source/drain coupled to the plurality of diode connected transistors and a second source/drain coupled to the second power supply connection;
a first resistor coupled between a gate of the first MOS transistor and the first source/drain; and
a second resistor coupled between the gate and the second source/drain.