US-12619268-B2 - Current sensing circuit with temperature coefficient compensation

Abstract

A current sensing circuit includes a first field-effect transistor (FET) coupled to a first current source, an inductor, and a power FET, and includes a second FET coupled to a second current source. The current sensing circuit also includes a temperature circuit coupled to the first FET and the second FET. The temperature circuit is configured to compensate for one or more differences between one or more temperature coefficients of one or more of the first FET, the second FET, and the power FET.

Inventors

• Jing Xue
• Chongli Cai
• ZIYU XIA
• JITENDRA K AGRAWAL
• JOEY YURGELON
• Hao Zhou

Assignees

• APPLE INC.

Dates

Publication Date

20260505

Application Date

20240222

Claims (20)

1. 1 . An apparatus, comprising: a first field-effect transistor (FET) coupled to a first current source, an inductor, and a power FET, wherein the first current source is configured to generate a first current; a second FET coupled to a second current source configured to generate a second current; and a temperature circuit coupled to the first FET and the second FET, wherein the temperature circuit configured to adjust a value of the second current based on respective temperature coefficients of one or more of the first FET, the second FET, and the power FET.
2. 2 . The apparatus of claim 1 , wherein the temperature circuit comprises: a third FET and a fourth FET coupled in parallel; a fifth FET and a sixth FET coupled in parallel; a first resistor coupled to the first current source; and a second resistor coupled to the second current source.
3. 3 . The apparatus of claim 2 , wherein a gate of the third FET is coupled to the first current source, a gate of the fourth FET is coupled to the second current source, a gate of the fifth FET is coupled to the first current source; and a gate of the sixth FET is coupled to the second current source.
4. 4 . The apparatus of claim 1 , wherein the inductor is coupled between the first FET and the power FET.
5. 5 . The apparatus of claim 1 , further comprising: a comparator circuit, wherein the comparator circuit includes the temperature circuit and wherein the temperature circuit comprises an input for the comparator circuit.
6. 6 . The apparatus of claim 5 , wherein the comparator circuit is configured to output a signal indicating when the first current matches a target current.
7. 7 . The apparatus of claim 5 , wherein the comparator circuit is coupled to a control FET and wherein the control FET is configured to start or halt a charge cycle based on a signal generated by the comparator circuit.
8. 8 . The apparatus of claim 1 , wherein the temperature circuit includes one or more resistors and wherein the temperature circuit is configured to adjust one or more resistances of the one or more resistors based on the temperature coefficients of one or more of the first FET, the second FET, and the power FET.
9. 9 . The apparatus of claim 1 , wherein the temperature circuit is further configured to adjust the first current based on the temperature coefficients of one or more of the first FET, the second FET, and the power FET.
10. 10 . The apparatus of claim 1 , wherein the power FET is external to the apparatus.
11. 11 . A method, comprising: providing a first current from a first current source to a first FET, a temperature circuit, and a power FET; providing a second current from a second current source to a second FET and the temperature circuit; and adjusting the second current based on one or more temperature coefficients of one or more of the first FET, the second FET, and a temperature coefficient of the power FET.
12. 12 . The method of claim 11 , further comprising: determining whether the first current matches a target current.
13. 13 . The method of claim 12 , further comprising: in response to determining that the first current matches the target current, halting a charge cycle of a power converter circuit.
14. 14 . The method of claim 12 , further comprising: in response to determining that the first current matches the target current, starting a charge cycle of a power converter circuit.
15. 15 . The method of claim 11 , further comprising adjusting one or more resistances of one or more resistors based on one or more temperature coefficients of one or more of the first FET, the second FET, and a temperature coefficient of the power FET.
16. 16 . The method of claim 11 , further comprising adjusting the first current.
17. 17 . An apparatus, comprising: a voltage regulator circuit that includes a switch node coupled to a regulated power supply node via an inductor, wherein the voltage regulator circuit is configured to source a charge current to the switch node during a charge cycle; a current sensing circuit comprising: a first field-effect transistor (FET) coupled to a first current source, the inductor, and a power FET, wherein the first current source is configured to generate a first current; a second FET coupled to a second current source configured to generate a second current; and a comparator circuit coupled to the first FET and the second FET, wherein the comparator circuit is configured to: adjust the second current based on one or more temperature coefficients of one or more of the first FET, the second FET, and the power FET; and determine whether the charge current from the first current source matches a target current; and a control circuit configured to, in response to determining that the charge current matches the target current, start the charge cycle or stop the charge cycle.
18. 18 . The apparatus of claim 17 , wherein the comparator circuit includes one or more resistors and wherein the comparator circuit is further configured to adjust one or more resistances of the one or more resistors based on one or more temperature coefficients of one or more of the first FET, the second FET, and the power FET.
19. 19 . The apparatus of claim 17 , wherein the comparator circuit is configured to adjust the first current based on one or more temperature coefficients of one or more of the first FET, the second FET, and the power FET.
20. 20 . The apparatus of claim 17 , wherein the inductor is coupled between the first FET and the power FET.

Description

BACKGROUND Technical Field Embodiments described herein relate to integrated circuits, and more particularly, to techniques for measuring or sensing currents. Description of the Related Art Modern computer systems may include multiple circuits blocks designed to perform various functions. For example, such circuit blocks may include processors, processor cores configured to execute software or program instructions. Additionally, the circuit blocks may include memory circuits, mixed-signal or analog circuits, and the like. In some computer systems, the circuit blocks may be designed to operate at different power supply voltage levels. Power management circuits may be included in such computer systems to generate and monitor varying power supply voltage levels for the different circuit blocks. Power management circuits often include one or more power converter circuits configured to generate regulator voltage levels on respective power supply signals using a voltage level of an input power supply signal. Such regulator circuits may employ multiple passive circuit elements, such as inductors, capacitors, and the like. SUMMARY OF VARIOUS EMBODIMENTS Various embodiments of a current sensing circuit are disclosed. Broadly speaking, a current sensing circuit and/or a temperature circuit for the current sensing circuit are contemplated. The current measuring circuit may use the temperature circuit to compensate for differences in temperature coefficients between one or more field-effect transistors (FETs) of the current measuring circuit. The current measuring circuit may include a first FET, a second FET, an inductor, and the temperature circuit. The temperature circuit may include a first set of FETs, a second set of FETs, a first resistor, and a second resistor. Various embodiments of a power converter circuit are also disclosed. Broadly speaking, the power converter circuit for sourcing a charge current to another device/circuit are contemplated. The power converter circuit may include a current sensing circuit configured to measure, detect, sense, etc., the amount of charge current sourced to the other device/circuit. The current measuring circuit includes a temperature circuit to compensate for differences in temperature coefficients between one or more field-effect transistors (FETs) of the current measuring circuit. BRIEF DESCRIPTION OF THE DRAWINGS The following detailed description makes reference to the accompanying drawings, which are now briefly described. FIG. 1 illustrates a diagram of an example power converter circuit, in accordance with one or more embodiments of the present disclosure. FIG. 2 illustrates a diagram of an example voltage regulator circuit, in accordance with one or more embodiments of the present disclosure. FIG. 3 illustrates a block diagram of an example control circuit for a power converter circuit, in accordance with one or more embodiments of the present disclosure. FIG. 4 illustrates a block diagram of an example current sensing circuit, in accordance with one or more embodiments of the present disclosure. FIG. 5 illustrates a block diagram of an example current sensing circuit, in accordance with one or more embodiments of the present disclosure. FIG. 6 illustrates a block diagram of an example temperature circuit, in accordance with one or more embodiments of the present disclosure. FIG. 7 illustrates a flow diagram depicting an embodiment of a method for sensing a current, in accordance with one or more embodiments of the present disclosure. FIG. 8 illustrates a block diagram of an example computer system, in accordance with one or more embodiments of the present disclosure. While the disclosure is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that the drawings and detailed description thereto are not intended to limit the disclosure to the particular form illustrated, but on the contrary, the intention is to cover all modifications, equivalents and alternatives falling within the spirit and scope of the present disclosure as defined by the appended claims. The headings used herein are for organizational purposes only and are not meant to be used to limit the scope of the description. As used throughout this application, the word “may” is used in a permissive sense (i.e., meaning having the potential to), rather than the mandatory sense (i.e., meaning must). Similarly, the words “include,” “including,” and “includes” mean including, but not limited to. Various units, circuits, or other components may be described as “configured to” perform a task or tasks. In such contexts, “configured to” is a broad recitation of structure generally meaning “having circuitry that” performs the task or tasks during operation. As such, the unit/circuit/component can be configured to perform the task even when the unit/circuit/compon