Patent Application
20180301926
This Application claims priority of Taiwan Patent Application No. 106112882 filed on Apr. 18, 2017, the entirety of which is incorporated by reference herein.
The disclosure generally relates to a tunable power supply device, and more particularly, to a tunable power supply device and a parallel power supply system for automatically calibrating an output voltage.
A conventional electronic device usually includes a single direct current (DC) battery used as an electric power source. Even if a user has two or more DC batteries, they cannot simultaneously supply electric power to the electronic device. Generally, DC batteries have a variety of output standards (e.g., different voltages), and therefore the DC batteries cannot provide electric power together when they are coupled in parallel.
In order to solve the above problem, there is a need to design a novel solution, so that one or more DC batteries with different standards can simultaneously provide electric power for the same electronic device.
In a preferred embodiment, the invention is directed to a tunable power supply device with an input node and an output node. The tunable power supply device includes a voltage control module, a first diode, and a voltage divider circuit. The voltage control module converts an input voltage at the input node into a median voltage at a first node. The median voltage is determined according to a feedback voltage. The first diode has an anode coupled to the first node, and a cathode coupled to the output node for outputting an output voltage. The voltage divider circuit generates the feedback voltage according to the output voltage.
In some embodiments, the voltage divider circuit includes a first resistor and a second resistor. The first resistor is coupled between the output node and a second node. The second resistor is coupled between the second node and a ground voltage. The second node is arranged for outputting the feedback voltage.
In some embodiments, the voltage control module controls the median voltage such that the output voltage is equal to a target system voltage. The resistances of the first resistor and the second resistor are determined according to the target system voltage.
In some embodiments, the voltage control module is a buck circuit.
In some embodiments, the buck circuit includes a comparator, a pulse width modulation (PWM) controller, a first buffer, a second buffer, a first N-type transistor, a second. N-type transistor, an inductor, and a capacitor. The comparator compares the feedback voltage with a reference voltage, so as to generate a comparison voltage. The PWM controller generates a first control signal and a second control signal. The pulse widths of the first control signal and the second control signal are adjusted according to the comparison voltage. The first buffer is configured to buffer the first control signal. The second buffer is configured to buffer the second control signal. The first N-type transistor has a control terminal for receiving the first control signal through the first buffer, a first terminal coupled to a third node, and a second terminal coupled to the input node. The second N-type transistor has a control terminal for receiving the second control signal through the second buffer, a first terminal coupled to a ground voltage, and a second terminal coupled to the third node. The inductor is coupled between the third node and the first node. The capacitor is coupled between the first node and the ground voltage.
In some embodiments, the voltage control module is a boost circuit.
In some embodiments, the boost circuit includes a comparator, a pulse width modulation (PWM) controller, an inductor, a first N-type transistor, a second diode, and a capacitor. The comparator compares the feedback voltage with a reference voltage, so as to generate a comparison voltage. The PWM controller generates a first control signal. The pulse width of the first control signal is adjusted according to the comparison voltage. The inductor is coupled between the input node and a third node. The first N-type transistor has a control terminal for receiving the first control signal, a first terminal coupled to a ground voltage, and a second terminal coupled to the third node. The second diode has an anode coupled to the third node, and a cathode coupled to the first node. The capacitor is coupled between the first node and the ground voltage.
In some embodiments, the voltage control module is a boost-buck circuit.
In some embodiments, the boost-buck circuit includes a comparator, a pulse width modulation (PWM) controller, a first buffer, a second buffer, a first N-type transistor, a second. N-type transistor, an inductor, a second diode, a third diode, and a capacitor. The comparator compares the feedback voltage with a reference voltage, so as to generate a comparison voltage. The PWM controller generates a first control signal and a second control signal. The pulse widths of the first control signal and the second control signal are adjusted according to the comparison voltage. The first buffer is configured to buffer the first control signal. The second buffer is configured to buffer the second control signal. The first N-type transistor has a control terminal for receiving the first control signal through the first buffer, a first terminal coupled to a third node, and a second terminal coupled to the input node. The second N-type transistor has a control terminal for receiving the second control signal through the second buffer, a first terminal coupled to a ground voltage, and a second terminal coupled to a fourth node. The inductor is coupled between the third node and the fourth node. The second diode has an anode coupled to the fourth node, and a cathode coupled to the first node. The third diode has an anode coupled to the ground voltage, and a cathode coupled to the third node. The capacitor is coupled between the first node and the ground voltage.
In another preferred embodiment, the invention is directed to a parallel power supply system including a plurality of tunable power supply devices, each as claimed above. The plurality of tunable power supply devices are coupled in parallel, so as to generate the same output voltage.
In some embodiments, the voltage control modules of the plurality of tunable power supply devices comprise a boost circuit, a buck circuit, a boost-buck circuit, or a combination thereof.
The invention can be more fully understood by reading the subsequent detailed description and examples with references made to the accompanying drawings, wherein:
In order to illustrate the foregoing and other purposes, features and advantages of the invention, the embodiments and figures of the invention will be described in detail as follows.
Certain terms are used throughout the description and following claims to refer to particular components. As one skilled in the art will appreciate, manufacturers may refer to a component by different names. This document does not intend to distinguish between components that differ in name but not function. In the following description and in the claims, the terms “include” and “comprise” are used in an open-ended fashion, and thus should be interpreted to mean “include, but not limited to . . . ”. The term “substantially” means the value is within an acceptable error range. One skilled in the art can solve the technical problem within a predetermined error range and achieve the proposed technical performance. Also, the term “couple” is intended to mean either an indirect or direct electrical connection. Accordingly, if one device is coupled to another device, that connection may be through a direct electrical connection, or through an indirect electrical connection via other devices and connections.
The voltage control module 110 can convert the input voltage VIN at the input node NIN into a median voltage VM at a first node N1. The median voltage VM is determined according to a feedback voltage VFB. For example, the median voltage VM may be higher than, equal to, or lower than the original input voltage VIN. The first diode 121 has an anode coupled to the first node N1 for receiving the median voltage VM, and a cathode coupled to the output node NOUT for generating the output voltage VOUT. The first diode 121 can block an output current flowing back from the output node NOUT, and effectively prevent the output voltage VOUT and the output current from directly interfering with the voltage control module 110. The voltage divider circuit 130 generates the feedback voltage VFB according to the output voltage VOUT. The feedback voltage VFB may be a predetermined percentage of the output voltage VOUT (e.g., 30% or 40% of the output voltage VOLT, but it is not limited thereto). In some embodiments, the voltage divider circuit 130 includes a first resistor R1 and a second resistor R2. The first resistor R1 is coupled between the output node NOUT and a second node N2. The second resistor R2 is coupled between the second node N2 and a ground voltage VSS. The second node N2 is arranged for outputting the feedback voltage VFB to the voltage control module 110. The feedback voltage VFB is calculated according to the following equation (I).
where “VFB” represents the voltage level of the feedback voltage VFB, “R1” represents the resistance of the first resistor R1, “R2” represents the resistance of the second resistor R2, and “VOUT” represents the voltage level of the output voltage VOUT.
The voltage control module 110 can control the median voltage VM according to the feedback voltage VFB with a negative feedback mechanism, such that the final output voltage VOUT can be equal to the target system voltage. In some embodiments, the resistances of the first resistor R1 and the second resistor R2 are determined according to the aforementioned target system voltage.
With the proposed design of the invention, regardless of the voltage level of the original input voltage VIN, the tunable power supply device 100 can adjust it and output the same target system voltage. Accordingly, when there are a plurality of tunable power supply devices 100 for respectively receiving a plurality of different input voltages VIN, these tunable power supply devices 100 can be coupled in parallel with each other and simultaneously supply the same output voltage VOUT to an electronic device or a mobile device, thereby effectively enhancing the whole efficiency of power supply.
The following embodiments will introduce the detailed circuit structure and implement method of the tunable power supply device 100. It should be understood that these figures and embodiments are just exemplary, rather than limitations of the claim scope of the invention.
The first buffer 213 is configured to buffer the first control signal SC1. The second buffer 214 is configured to buffer the second control signal SC2. Each of the first N-type transistor MN1 and the second N-type transistor MN2 may be an N-type metal-oxide-semiconductor field-effect transistor (i.e., an N-type MOSFET or an NMOS transistor). The first N-type transistor MN1 has a control terminal for receiving the first control signal SC1 through the first buffer 213, a first terminal coupled to a third node N3, and a second terminal coupled to the input node NIN for receiving the input voltage VIN. The second N-type transistor MN2 has a control terminal for receiving the second control signal SC2 through the second buffer 214, a first terminal coupled to the ground voltage VSS, and a second terminal coupled to the third node N3. The inductor is coupled between the third node N3 and the first node N1. The capacitor C1 is coupled between the first node N1 and the ground voltage VSS. The first node N1 is arranged for outputting the median voltage VM, so as to indirectly fine-tune the output voltage VOUT. It should be noted that the input voltage VIN of the tunable power supply device 200 should be higher than the desired target system voltage since the voltage control module 210 is a buck circuit. Other features of the tunable power supply device 200 of
The inductor L1 is coupled between the input node NIN and a third node N3, and is arranged for receiving the input voltage VIN. The first N-type transistor MN1 may be an N-type metal-oxide-semiconductor field-effect transistor (i.e., an N-type MOSEET or an NMOS transistor). The first N-type transistor MN1 has a control terminal for receiving the first control signal SC1, a first terminal coupled to the ground voltage VSS, and a second terminal coupled to the third node N3. The second diode 122 has an anode coupled to the third node N3, and a cathode coupled to the first node N1. The capacitor C1 is coupled between the first node N1 and the ground voltage VSS. The first node N1 is arranged for outputting the median voltage VM, so as to indirectly fine-tune the output voltage VOUT. It should be noted that the input voltage VIN of the tunable power supply device 400 should be lower than the desired target system voltage since the voltage control module 410 is a boost circuit. Other features of the tunable power supply device 400 of
The first buffer 513 is configured to buffer the first control signal SC1. The second buffer 514 is configured to buffer the second control signal SC2. Each of the first N-type transistor MN1 and the second N-type transistor MN2 may be an N-type metal-oxide-semiconductor field-effect transistor (i.e., an N-type MOSFET or an NMOS transistor). The first N-type transistor MN1 has a control terminal for receiving the first control signal SC1 through the first buffer 513, a first terminal coupled to a third node N3, and a second terminal coupled to the input node NIN for receiving the input voltage YIN. The second N-type transistor MN2 has a control terminal for receiving the second control signal SC2 through the second buffer 514, a first terminal coupled to the ground voltage VSS, and a second terminal coupled to a fourth node N4. The inductor L1 is coupled between the third node N3 and the fourth node N4. The second diode 122 has an anode coupled to the fourth node N4, and a cathode coupled to the first node N1. The third diode 123 has an anode coupled to the ground voltage VSS, and a cathode coupled to the third node N3. The capacitor C1 is coupled between the first node N1 and the ground voltage VSS. The first node N1 is arranged for outputting the median voltage VM, so as to indirectly fine-tune the output voltage VOUT. It should be noted that the input voltage VIN of the tunable power supply device 500 should be higher than, equal to, or lower than the desired target system voltage since the voltage control module 510 is a boost-buck circuit. Other features of the tunable power supply device 500 of
In conclusion, compared with the conventional design, the proposed tunable power supply device and parallel power supply system of the invention have at least the advantages of (1) tuning battery sources with different voltages to generate the same output voltage, (2) using a diode at the output node to prevent an output current from flowing back, and to prevent the whole circuit from being damaged, (3) requiring no additional current detection element as the conventional design, (4) providing a parallel arrangement to enhance the efficiency of DC power supply, and (5) reducing the total manufacturing cost. Therefore, the invention is suitable for application in a variety of electronic devices or mobile devices which require DC electric supply sources.
Note that the above element parameters are not limitations of the invention. A designer can fine-tune these settings or values according to different requirements. It should be understood that the tunable power supply device and parallel power supply system of the invention are not limited to the configurations of
Use of ordinal terms such as “first”, “second”, “third”, etc., in the claims to modify a claim element does not by itself connote any priority, precedence, or order of one claim element over another or the temporal order in which acts of a method are performed, but are used merely as labels to distinguish one claim element having a certain name from another element having the same name (but for use of the ordinal term) to distinguish the claim elements.
It will be apparent to those skilled in the art that various modifications and variations can be made in the invention. It is intended that the standard and examples be considered as exemplary only, with the true scope of the disclosed embodiments being indicated by the following claims and their equivalents.
| Number | Date | Country | Kind |
|---|---|---|---|
| 106112882 | Apr 2017 | TW | national |
