Apparatus for controlling power consumption in PDA phone

An apparatus for controlling power consumption in a Personal Digital Assistant (PDA) phone is provided. The apparatus includes a PDA controller for applying a first signal or a second signal to a PDA voltage module, for sensing a voltage of a first capacitor changed according to the first or second signal, and for operating at the voltage of the first capacitor, and the PDA voltage module in which a first resistor is in a shorted or open condition according to the first or second signal, and a voltage applied to the first capacitor is changed according to the shorted or open condition of the first resistor.

PRIORITY

This application claims the benefit under 35 U.S.C. §119(a) of a Korean patent Application filed in the Korean Intellectual Property Office on Nov. 21, 2006 and assigned Serial No. 2006-115273, the entire disclosure of which is hereby incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to a wireless terminal. More particularly, the present invention relates to an apparatus for controlling power consumption in a Personal Digital Assistant (PDA) phone.

2. Description of the Related Art

In general, a device in which both a Personal Digital Assistant (PDA) function and a wireless terminal function are implemented is a PDA phone or a smart phone. The PDA phone has basic PDA functions, such as a portable computer function, an electronic note function, an Internet search function, and a cellular phone function such as a conventional wireless phone function. In general, wireless terminals, such as a PDA phone, use a battery pack for operational power. However, the battery pack used in wireless terminals has limited power because of its small size. Accordingly, a method of saving power consumption is very important. More specifically, a desirable feature of PDA phones is their ability to perform multitasking. However, much power is consumed during multitasking. Thus, the performance and sales of PDA phones depend on a battery's capacity or useable time. In the past, in order to increase a useable time of a PDA phone, power consumed in the PDA phone was minimized by varying a core clock of a PDA controller using a Power Management Integrated Circuit (PMIC). However, in general, a circuit configuration using the PMIC is difficult to implement. Also, a volume of a circuit configuration using the PMIC is large. Thus, it is desired to increase a useable time of a PDA phone by minimizing power consumption of the PDA phone using a simple circuit configuration without a separate chip such as the PMIC.

SUMMARY OF THE INVENTION

An aspect of the present invention is to address at least the above-mentioned problems and/or disadvantages and to provide at least the advantages described below. Accordingly, an aspect of the present invention is to provide an apparatus for minimizing power consumption in a Personal Digital Assistant (PDA) phone using a simple circuit configuration.

According to one aspect of the present invention, an apparatus for controlling power consumption in a Personal Digital Assistant (PDA) phone is provided. The apparatus includes a PDA controller for supplying a first signal or a second signal, for sensing a voltage of a first capacitor changed according to the first or second signal, and for operating at the voltage of the first capacitor and a PDA voltage module in which a first resistor is shorted or open according to the first or second signal, and a voltage applied to the first capacitor is changed according to the shorted or open condition of the first resistor.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects, features and advantages of certain exemplary embodiments of the present invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings in which:

FIG. 1is a block diagram illustrating a Personal Digital Assistant (PDA) phone according to an exemplary embodiment of the present invention;

FIG. 2is a circuit diagram illustrating a PDA voltage module according to an exemplary embodiment of the present invention;

FIG. 3is a circuit diagram illustrating a PDA voltage module to which a first signal is applied, according to an exemplary embodiment of the present invention; and

FIG. 4is a circuit diagram illustrating a PDA voltage module to which a second signal is applied, according to an exemplary embodiment of the present invention.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

FIG. 1is a block diagram illustrating a Personal Digital Assistant (PDA) phone according to an exemplary embodiment of the present invention.

Referring toFIG. 1, a key input unit27includes keys to input number and character information and function keys to set various functions. The key input unit27receives key input data of a user and transmits the key input data to a PDA controller10a.

A radio transceiver23performs a wireless communication function of the PDA phone and includes a Radio Frequency (RF) module (not shown) and a modem (not shown). The RF module includes an RF transmitter (not shown) for up-converting a frequency of a signal to be transmitted and for amplifying the frequency up-converted signal. The RF module also includes an RF receiver (not shown) for low noise amplifying a received signal and down-converting a frequency of the low noise amplified signal. The modem includes a transmitter (not shown) for encoding and modulating a signal to be transmitted and a receiver (not shown) for demodulating and decoding a signal received from the RF module.

An audio processing unit25can include a codec including a data codec and an audio codec. The data codec processes packet data, and the audio codec processes an audio signal such as voice and a multimedia file. The audio processing unit25converts a digital audio signal received from the modem to an analog audio signal using the audio codec and reproduces the analog audio signal. The audio processing unit25may also convert an analog audio signal generated by a microphone to a digital audio signal and transmit the digital audio signal to the modem. The codec may exist separately or be included in the PDA controller10aor a phone controller10b.

A PDA memory module30aand a phone memory module30bcan be comprised of Read Only Memory (ROM) or Random Access Memory (RAM). The PDA memory module30aand the phone memory module30bcan be comprised of a program memory and a data memory and store programs for controlling an operation of the PDA phone and data for booting. The PDA memory module30aand the phone memory module30bcan be configured in a single memory or separately.

A display unit50displays an image corresponding to an image signal and user data output from the PDA controller10aon a screen. The display unit50also displays data related to a phone call, which is output from the phone controller10b. The display unit50can be made up of a Liquid Crystal Display (LCD) or Organic Light Emitting Diodes (OLED). If the LCD or OLED is implemented using a touch screen, the display unit50may operate as an input unit for controlling the PDA phone together with the key-input unit27.

A PDA voltage module70includes a circuit for changing an operational voltage of the PDA controller10a.As will be explained in more detail with reference toFIG. 2, the PDA voltage module70applies a voltage, which is changed according to a first or second signal input from the PDA controller10a,to a first capacitor76.

The PDA controller10acontrols a general operation of the PDA phone. The PDA controller10aaccording to an exemplary embodiment of the present invention applies the first or second signal to the PDA voltage module70and operates with the voltage of the first capacitor76, which is changed according to the first or second signal. Thus, the PDA controller10aaccording to an exemplary embodiment of the present invention operates at a low operational voltage if the voltage of the first capacitor76is low, or operates at a high operational voltage if the voltage of the first capacitor76is high. Thus, the PDA controller10aaccording to an exemplary embodiment of the present invention can operate at a low clock frequency with the low operational voltage or operate at a high clock frequency with the high operational voltage. The phone controller10bcontrols a general operation for a phone call function.

FIG. 2is a circuit diagram illustrating a PDA voltage module70according to an exemplary embodiment of the present invention.

Referring toFIG. 2, an exemplary PDA voltage module70includes a switch71, a first resistor72, a second resistor73, a third resistor74, a voltage applying unit75, and the first capacitor76. The PDA voltage module70may include a circuit (L1and C2) to prevent oscillation of the voltage applying unit75.

The switch71is turned on according to the first signal input from the PDA controller10aand is turned off according to the second signal. In an exemplary embodiment, the switch71is a transistor that is turned on/off according to the first/second signal (e.g., a voltage for turning the transistor on or off).

The third resistor74is connected to the second resistor73in series, and the second resistor73is connected to the first resistor72in parallel. The first resistor72is connected to the switch71. If the switch71is turned on, because the first resistor72is connected to the second resistor73in parallel, a voltage applied to the second resistor73is dropped. Conversely, if the switch71is turned off, the first resistor72is open and the voltage applied to the second resistor is not dropped.

If a driving signal PWR_EN is input, the voltage applying unit75operates by receiving a voltage from a battery voltage source VBat and raises or drops a voltage output via a port B according to a bias voltage (the voltage of the second resistor73input via a port A). The voltage of the second resistor73is changed according to an open or shorted condition of the first resistor72, and the voltage output via the port B is applied to the first capacitor76. In an exemplary embodiment, the voltage applying unit75is a Direct Current (DC)-to-DC converter. The DC-to-DC converter is a device (or circuit) for outputting an input DC voltage as a DC voltage. That is, the DC-to-DC converter generates an Alternating Current (AC) voltage by switching the input DC voltage and generates an output DC voltage by raising/dropping and rectifying the AC voltage. In another exemplary embodiment, the voltage applying unit75is a Low Dropout Regulator (LDO). The LDO may be used when a difference between an input voltage and an output voltage is small.

FIG. 3is a circuit diagram illustrating a PDA voltage module70to which the first signal is applied, according to an exemplary embodiment of the present invention.FIG. 4is a circuit diagram illustrating a PDA voltage module70to which the second signal is applied, according to an exemplary embodiment of the present invention. The operations illustrated inFIGS. 3 and 4will now be described with reference toFIG. 2.

In an exemplary embodiment, the switch71is a transistor and a gate of the transistor is turned on or off according to the first or second signal input from the PDA controller10a.According to an on or off state of the transistor, the first resistor72is connected to the second resistor73in parallel or the first resistor72is in an open state, respectively. Furthermore, according to the parallel connection or open state of the first resistor72, the voltage applied to the second resistor73is dropped (when the first resistor72is connected to the second resistor73in parallel) or raised (when the first resistor72is open). The voltage applied to the second resistor73is input to the voltage applying unit75via the port A. The voltage input via the port A acts as a bias voltage to change the voltage output from the voltage applying unit75via the port B. The voltage output via the port B is applied to the first capacitor76. If the first resistor72is not connected to the second resistor73in parallel, the PDA voltage module70is equivalent to the circuit illustrated inFIG. 3. If the first resistor72is connected to the second resistor73in parallel, the PDA voltage module70is equivalent to the circuit illustrated inFIG. 4. That is, the voltage applied to the first capacitor76is changed according to whether or not the first resistor72is connected to the second resistor73in parallel. The PDA controller10aoperates at the voltage of the first capacitor76. In this case, if the voltage of the first capacitor76is raised (corresponding toFIG. 3), the PDA controller10amay operate by setting a clock speed higher, and if the voltage of the first capacitor76is dropped (corresponding toFIG. 4), the PDA controller10amay operate by setting the clock speed lower. Thus, if an operating application needs a small amount of computation by the PDA controller10a, the PDA controller10aoperates at a low voltage and a low clock frequency by applying the second signal to the PDA voltage module70. If an operating application needs a large amount of computation by the PDA controller10a, the PDA controller10aoperates at a high voltage and a high clock frequency by applying the first signal to the PDA voltage module70.

As described above, according to exemplary embodiments of the present invention, by minimizing power consumption in a PDA phone without a complex circuit configuration, a useable time of the PDA phone can be maximized.