US 20050162123 A1
The disclosed embodiments relate to power systems and methods. One such power system includes an adapter that produces a power output. A converter stage receives the power output and in turn provides a regulated output. The regulated output is delivered to a battery and to a DC-DC component.
6. An electronic device comprising:
a memory capable of storing data to be accessed by the processor; and
a power system comprising:
a power adapter capable of producing a power output;
a converter stage coupled to receive the power output and generate a regulated output;
a DC-DC component coupled to receive the regulated output; and
a battery removably coupled to receive the regulated output.
7. The power system set forth in
8. The power system set forth in
9. The power system set forth in
10. The power system set forth in
11. The power system set forth in
a first switch connected to a terminal of the battery; and
a second switch connected between the first switch and the feedback circuit, wherein the first and second switches enable the charging of the battery.
12. The power system set forth in
13. The power system set forth in
Portable computing devices may derive power from internal batteries, which may be charged by being connected to an external source of AC or DC power. When charged, the battery may be used to power the portable computing device when no source of AC or DC power is readily available. Additionally, the battery may function as back-up power when there is a disruption to AC or DC power used to power the portable device. When the portable device is operating on AC or DC power, the battery may be recharging for later use as a primary supply of power.
In designing the power system of personal computing devices, the configuration and layout of components may affect the operation and efficiency of the device. For instance, improper placement of components may result in problems, such as increasing potential damages to batteries, decreasing efficiency, or reducing the amount of time that the battery is able to provide power for the portable device.
Standards relating to the design of power systems for portable computing devices exist. One such standard is the Smart Battery System v1.1. Other standards include the Intelligent Battery Architecture, version 2 (“IBA”) and the Constant Power Adapter (“CPA”) method. These standards may inhibit efficiency in power systems.
In one embodiment of the present invention, a power system for a processor-based electronic system comprises a power adapter for producing a power output. A converter stage receives the power output and generates a regulated power. The regulated output is delivered to a battery and to a DC-DC component.
Another embodiment relates to a method of operation for a power system. The method comprises producing a power output, delivering the power output to a converter, regulating the power output, delivering the regulated output to a DC-DC component and a battery. The battery charges from the regulated output, while the DC-DC component adjusts the regulated output into a plurality of voltages for a plurality of circuits.
The foregoing and other advantages of the invention may become apparent upon reading the following detailed description and upon reference to the drawings in which
Referring initially to
The system 10 includes a power supply 14, which may comprise a battery or batteries, an AC power adapter and/or a DC power adapter. Various other devices may be coupled to the processor 12 depending on the functions that the system 10 performs. For example, an input device 16 may be coupled to the processor 12 to receive input from a user. The input device 16 may comprise a user interface and may include buttons, switches, a keyboard, a light pen, a mouse, a digitizer and/or a voice recognition system or the like. An audio or video display 18 may also be coupled to the processor 12 to provide information to the user.
A communications port 22 may be adapted to provide a communication interface between the electronic device 10 and peripheral devices 24. The peripheral 24 may include a docking station, expansion bay or other external component. Furthermore, an RF sub-system/baseband processor 20 may be coupled to the processor 12 to provide wireless communication capability.
A current sense resistor 56 is connected between the converter stage 40 and a common connection to a first battery 34 and a second battery 36. The current sense resistor 56 provides feedback regarding the amount of current that is flowing to or from the batteries 34 and 36. The battery 34 comprises a switch 58 and a switch 62, which are connected in series to a battery cell stack 64. The battery 36 comprises a switch 60 and a switch 66, which are connected in series to a battery cell stack 68.
If the adaptor 38 is connected to a power source, power from the adaptor 38 will flow through the converter stage 40 to the DC-DC component 42 and the batteries 34 and 36. The converter stage 40 regulates the output through the switch 48 and maintains a voltage level sufficient to ensure the power distributor or DC-DC component 42 is able to operate efficiently. In this mode, the batteries 34 and 36 can charge. By placing the switches 58 and 62 in the battery 34 in a back-to-back configuration, current flows into the battery cell stack 64 when the switches 58 and 62 are turned “on.” The same is true for the switches 60 and 66, which control the flow of current to the battery cell stack 68. Conversely, when the battery 34 or the battery 36 is charged, the switches 58 and 62 (for the battery 34), and switches 60 and 66 (for the battery 36) may be turned “off” to block current from flowing to the respective batteries.
Alternatively, if the adaptor 38 is not providing power, the switches 58 and 62 (for the battery 34) or the switches 60 and 66 for the battery 36 may be turned “on” to power the system 10 (
The regulation of the power output from the switch 48 enables the use of switches with lower voltages ratings than would otherwise be possible for the switches 58, 60, 62 and 66. As an example, such regulation enables the batteries 34 and 36, as well as the DC-DC component 42, to be configured to receive a maximum of about 16.8 volts DC. This enables the use of 20-volt switches for the switches 58, 60, 62 and 66, and also in the DC-DC component 42, where more robust and expensive switches would otherwise be needed. The use of MOSFET switches with lower voltage additionally saves power by reducing the voltage drop across the switches relative to switches with higher voltage ratings.
A first feedback component is connected across the battery cell stack 64 and a second feedback component 72 is connected across the battery cell stack 68. The outputs of the two feedback components 70 and 72 are combined to form an input to an interface component 74, which provides input to the switch 48. The first feedback component 70, the second feedback component 72, and/or the interface component 74 may be internal or external to the respective batteries.
The interface component 74 controls the operation of the switch 48, including the current flow through the switch 48, based on the input it receives from the feedback components 70 and 72. This input is influenced by various factors, such as the status of the batteries 34 and 36 and whether the adaptor 38 is supplying power. For instance, if neither battery 34 nor 36 needs to be charged or if the adaptor 38 is not supplying power, then the interface component 74 does not send control signals to the switch 48 to adjust the current flow. However, if the batteries 34 or 36 require charging, then the switch 48 is used to regulate the charging process. The charging process is regulated by using signals from the battery feedback components 70 and 72 to the interface component 74 to adjust the current flow into the batteries 34 and 36. If the current flow through the switch 48 is to be increased or decreased, then the interface component 74 transmits the appropriate signal to the switch 48.
The resistor 84 is connected between the terminal 80 and an input to an amplifier 88, which has a feedback capacitor 90 connected thereto. The resistor 86 is connected between the same input of the amplifier 88 and a first terminal (cathode) of a diode 92. The resistor 94 is connected between the first terminal (cathode) of the diode 92 and the terminal 82 of the battery cell stack 78. The second terminal (anode) of diode 92 is connected to the output of amplifier 102.
A resistor 98 is connected across the second terminal 82 and an input of the amplifier 102, which also has a grounded capacitor 101 connected thereto. The other input of the amplifier 102 is connected to a grounded resistor 108 and a feedback capacitor 104. The other end of capacitor 104 is connected to the output of the amplifier 102. The resistor 106 is connected across a reference signal input 105 and resistor 108, so resistor 108 is used to set a reference voltage for the amplifier 102. The reference signal input 105 is connected to an input of the amplifier 88.
If a current received at the amplifier 102 is higher than an expected value or range, then the output voltage signal from the amplifier 102 increases. This increase may turn “on” the feedback diode 92, which results in current being fed through the resistor 94. As the current flows through the resistor 94, the voltage across the feedback diode 92 may increase, which causes the output voltage of the amplifier 88 to decrease. In this manner, the charge current delivered by the converter stage 40 (
A connection point 112 functions as an analog feedback terminal that may allow the converter stage 40 (
The digital feedback terminal 114 or the analog feedback terminal 112 is connected to the converter stage 40 (
The output of the feedback circuit 100 is used to facilitate the operation of the switches 58, 60, 62, and 66 (
As discussed above with regard to the converter stage, the output power is processed into a regulated power or regulated output, as shown at block 138. For instance, the power is converted into a regulated DC power output, from either an AC or DC input source. The converter is designed to produce regulated power within a predefined range. At block 140, the regulated output is delivered to a DC-DC component, such as the DC-DC component 42 of