Power transistors with a resistor coupled to a sense transistor

Patent metadata

Field	Value
Publication number	US-10422818-B2
Application number	US-201715859470-A
Country	US
Kind code	B2
Filing date	Dec 30, 2017
Priority date	Dec 30, 2017
Publication date	Sep 24, 2019
Grant date	Sep 24, 2019

Abstract

An electronic device comprises: a first semiconductor die; a power transistor integrated in the first semiconductor die, the power transistor comprising a gate, a first terminal, and a second terminal; a sense transistor integrated in the first semiconductor die, the sense transistor comprising a gate coupled to the gate of the power transistor, a first terminal, and a second terminal coupled to the second terminal of the power transistor; and a first resistor integrated in the first semiconductor die, the first resistor comprising a polysilicon section and a metal section coupled to the polysilicon section, the first resistor comprising a first terminal and a second terminal, wherein the first terminal of the first resistor is coupled to the first terminal of the sense transistor.

First claim

What is claimed is:

1. An electronic device comprising:
a first semiconductor die;
a power transistor integrated in the first semiconductor die, the power transistor comprising a gate, a first terminal, and a second terminal, the power transistor having a channel resistance and parasitic resistances;
a sense transistor integrated in the first semiconductor die, the sense transistor comprising a gate coupled to the gate of the power transistor, a first terminal, and a second terminal coupled to the second terminal of the power transistor, the sense transistor having a channel resistance; and
a first resistor integrated in the first semiconductor die, the first resistor comprising a polysilicon section and a metal section coupled to the polysilicon section, the first resistor comprising a first terminal and a second terminal, wherein the first terminal of the first resistor is coupled to the first terminal of the sense transistor; the first resistor having a resistance matching the power transistor parasitic resistances multiplied by a ratio of the sense transistor channel resistance to the power transistor channel resistance.

2. The electronic device of claim 1 , wherein
the first terminal of the power transistor is a source of the power transistor,
the second terminal of the power transistor is a drain of the power transistor,
the first terminal of the sense transistor is a source of the sense transistor, and
the second terminal of the sense transistor is a drain of the power transistor.

3. The electronic device of claim 2 , wherein the power and sense transistors are each n-metal-oxide-semiconductor field-effect-transistors (nMOSFETs).

4. The electronic device of claim 2 , wherein the power and sense transistors are each p-metal-oxide-semiconductor field-effect-transistors (pMOSFETs).

5. The electronic device of claim 1 , wherein
the first terminal of the power transistor is a drain of the power transistor,
the second terminal of the power transistor is a source of the power transistor,
the first terminal of the sense transistor is a drain of the sense transistor, and
the second terminal of the sense transistor is a source of the power transistor.

6. The electronic device of claim 5 , wherein the power and sense transistors are each n-metal-oxide-semiconductor field-effect-transistors (nMOSFETs).

7. The electronic device of claim 5 , wherein the power and sense transistors are each p-metal-oxide-semiconductor field-effect-transistors (pMOSFETs).

8. The electronic device of claim 1 , further comprising a controller, the controller comprising:
a first node coupled to the second terminal of the first resistor; and
a second node coupled to first terminal of the power transistor.

9. The electronic device of claim 8 , further comprising:
a second semiconductor die, wherein the controller is integrated in the second semiconductor die.

10. The electronic device of claim 8 , the controller to provide a virtual connection from the second terminal of the first resistor to the first terminal of the power transistor.

11. The electronic device of claim 8 , the controller to maintain a first voltage at the first node to equal a second voltage at the second node.

12. The electronic device of claim 8 , the controller further comprising:
an operational amplifier comprising a first input port coupled to the first terminal of the power transistor, a second input port coupled to the first resistor, and an output port; and
a pass transistor having a gate coupled to the output port of the operational amplifier, and a drain coupled to the first resistor.

13. The electronic device of claim 8 , wherein the controller further comprises:
a second resistor comprising a first terminal coupled to the first node of the controller, and a second terminal;
the controller to provide a virtual connection from the second terminal of the second resistor to the first terminal of the power transistor.

14. The electronic device of claim 8 , wherein the controller further comprises:
a second resistor comprising a first terminal coupled to the first node of the controller, and a second terminal;
the controller to maintain a first voltage at the second terminal of the second resistor to equal a second voltage at the second node.

15. The electronic device of claim 8 , wherein the controller further comprises:
a second resistor comprising a first terminal coupled to the first node of the controller, and a second terminal;
an operational amplifier comprising a first input port coupled to the source of the power transistor, a second input port coupled to the second resistor, and an output port; and
a pass transistor having a gate coupled to the output port of the operational amplifier, and a drain coupled to the second resistor.

16. The electronic device of claim 8 , wherein the controller further comprises:
a second resistor comprising a first terminal coupled to the first node of the controller, and a second terminal.

17. The electronic device of claim 8 , wherein the controller further comprises:
a second resistor comprising a first terminal coupled to the first node of the controller, and a second terminal; and
a memory to store programming bits to program a resistance value of the second resistor.

18. An electronic device comprising:
a semiconductor die comprising a drain region;
a power transistor integrated in the semiconductor die, the power transistor comprising a gate and a source, the power transistor having a channel resistance and parasitic resistances;
a sense transistor integrated in the semiconductor die, the sense transistor comprising a gate coupled to the gate of the power transistor, and a source, wherein the power and sense transistors share the drain region, the sense transistor having a channel resistance; and
a resistor integrated in the semiconductor die, the resistor comprising a polysilicon section and a metal section coupled to the polysilicon section, the resistor coupled to the source of the sense transistor; the resistor having a resistance matching the power transistor parasitic resistances multiplied by a ratio of the sense transistor channel resistance to the power transistor channel resistance.

19. An electronic device comprising:
a semiconductor die comprising a source region;
a power transistor integrated in the semiconductor die, the power transistor comprising a gate and a drain, the power transistor having a channel resistance and parasitic resistances;
a sense transistor integrated in the semiconductor die, the sense transistor comprising a gate coupled to the gate of the power transistor, and a drain, wherein the power and sense transistors share the source region, the sense transistor having a channel resistance; and
a resistor integrated in the semiconductor die, the resistor comprising a polysilicon section and a metal section coupled to the polysilicon section, the resistor coupled to the drain of the sense transistor; the resistor having a resistance matching the power transistor parasitic resistances multiplied by a ratio of the sense transistor channel resistance to the power transistor channel resistance.

Assignees

• Texas Instruments Inc

Inventors

• Harjono Tikno
• Krishnamurthy Vijay
• Chu Min
• Joardar Kuntal
• Daum Gary Eugene
• Roy Subrato
• Hegde Vinayak
• Chauhan Ankur
• Vallamkonda Sathish
• Rahman Md Abidur
• Kim Eung Jung

Classifications

• H10W90/00

  Package configurations · CPC title

• G01R15/146 Primary

  Measuring arrangements for current not covered by other subgroups of G01R15/14, e.g. using current dividers, shunts, or measuring a voltage drop (if no voltage isolation is involved G01R1/203 or G01R19/0092) · CPC title

• H03K2217/0027

  Measuring means of, e.g. currents through or voltages across the switch · CPC title

• H03K17/567

  Circuits characterised by the use of more than one type of semiconductor device, e.g. BIMOS, composite devices such as IGBT · CPC title

• H01L27/0629

  Electricity · mapped topic