KR20080112844A - Portable terminal and it's charging apparatus - Google Patents

Abstract

A portable terminal and a charging apparatus for reducing a manufacturing cost and the complexity of the terminal are provided to protect damage or danger of the terminal by a USB type voltage adapter and to minimize a component by configuring an overvoltage-protection circuit and a charger circuit in a single chip. If power higher than the specified voltage is applied, an overvoltage-protection part(421) blocks overvoltage and the power source less than the specified voltage is outputted. A battery charger(420) performs battery charge by using the power source outputted through the overvoltage-protection part. A controller(440) controls the battery charge and charges the battery with electricity.

Description

PORTABLE TERMINAL AND IT'S CHARGING APPARATUS}

1 is a view for explaining an example of simultaneously performing battery charging and data communication of a mobile terminal through a USB port.

2A shows a USB type AC power adapter having a socket into which a USB cable can be inserted.

2B illustrates a USB type vehicle power adapter having a socket into which a USB cable can be inserted.

3 is a view showing a configuration of a dual charger provided in a conventional portable terminal.

Figure 4 is a view showing the configuration of a portable terminal having a charging device according to the present invention.

5 is a graph for explaining the characteristics of the overvoltage protection circuit provided in the charging device according to the present invention.

Figure 6 is a diagram showing another graph for explaining the characteristics of the overvoltage protection circuit provided in the charging device according to the present invention.

7 is a view showing an example of a brief switching circuit of a charging device having an overvoltage protection function according to the present invention.

8 is a view for explaining the configuration of an example power management module including a charging device according to the present invention.

9 is a view for explaining a configuration of an example power management module further including an overvoltage prevention circuit in FIG.

* Description of the symbols for the main parts of the drawings *

410: charging terminal 420: charger

430: battery 440: controller

The present invention relates to a portable terminal and a charging device thereof capable of protecting the terminal from overvoltage applied when the portable terminal is charged.

Conventional portable terminals only support the charging method of the battery using a power adapter. Recently, however, a charging method using a universal serial bus (USB) port is gradually supported.

Accordingly, a recent portable terminal is connected to a computer 102 having a USB port 101 as shown in FIG. 1, so that battery charging and data communication between the terminal and the computer can be simultaneously performed.

However, recently, as a power adapter capable of using a USB cable, as shown in FIGS. 2A and 2B, is being supplied, an overvoltage is being applied through the USB port 203. There are many cases where the controller of Burnout is burned out.

2A is a view showing a USB type power adapter 201 and a USB cable 202 having a socket into which an AC cable can be inserted into an AC power adapter. FIG. 2B is a vehicle power socket (eg, a cigar jack socket). Figure 1 shows a vehicle USB type power adapter that can be inserted into the vehicle. The same type of USB cable 202 as shown in FIG. 2A may be used for the vehicle USB type power adapter.

Hereinafter, a configuration of a charging circuit provided in a conventional portable terminal will be described with reference to FIG. 3.

FIG. 3 is a view illustrating a configuration of a dual charger provided in a conventional portable terminal, and the terminal TA for receiving power output from a power adapter (not shown) to the charging terminal 310 of the portable terminal. 301 and a terminal (USB, 302) for receiving the power output through the USB port is provided.

The power input through the terminals 301 and 302 has different voltage levels, and paths for processing the power are also different. Therefore, the chargers of the batteries 330 using the respective power sources must also be provided, but recently, the dual charger 320 made of a single chip is used in consideration of the manufacturing cost.

More specifically, a charger using a power adapter requires only two terminals (VCC, GND), and with this in mind, the withstand voltage of the charger is designed to be about 28V. However, chargers using the USB port require four terminals (VBUS, D +, D-, and GND), and the voltage level output from the USB port of the computer is constant at about 5V, so that the withstand voltage withstand the charger. Is designed to be about 7V.

For reference, the internal pressure affects the manufacturing cost of the charger 320.

However, due to the recent insufficiency and unstable power source of USB type power adapter (especially automobile power), overvoltage higher than the internal voltage (about 7V) of the charger using the USB port is increasing, resulting in charger burnout. Burn out often occurs. In addition, as the overvoltage is directly applied to the controller 340 of the terminal that detects the power input through the charging terminal 310, the controller 340 burns out.

Accordingly, an object of the present invention is to provide a portable terminal having an overvoltage protection circuit for protecting a chip of the terminal from an overvoltage input during charging of the portable terminal and a charging device thereof.

In addition, an object of the present invention is to provide a portable terminal having a dual charger in the form of a single chip having an overvoltage protection circuit and a charging device thereof.

Another object of the present invention is to provide a portable terminal including a single chip type dual charger having the overvoltage protection circuit and a controller for controlling the dual charger, and a charging device thereof.

In order to achieve the above object, the present invention cuts off the power when a predetermined voltage or more is applied, and performs a battery charging using an overvoltage prevention unit outputting only a power below the predetermined voltage and a power output through the overvoltage prevention unit. And a controller configured to charge the battery by controlling the charger when a stable power is continuously applied through the charger and the overvoltage protection unit.

In order to achieve the above object, the present invention receives power through a portable adapter (TA) or universal serial bus (USB) of a mobile terminal, and cuts off the power supply when the voltage of the power supply is above a certain level, and outputs only the power below a certain level. An overvoltage protection unit; And a charger for performing battery charging with the power output through the overvoltage protection unit under the control of a controller.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, in describing the present invention, detailed descriptions of well-known functions and configurations will be omitted for clarity. In addition, in describing the present invention with reference to the drawings, components that perform the same function will be described with the same reference numerals.

4 is a block diagram showing a configuration of a portable terminal having a charging device according to the present invention. Here, the portable terminal includes a 2.5G / 3G mobile phone, a PDA / smart phone, a Bluetooth headset, a PMP, a portable game machine, a digital camera, a digital camcorder, and a GPS terminal. In particular, it refers to a portable device using a single USB connector capable of both data communication and power supply.

Referring to FIG. 4, the portable terminal includes a charger 420 including a charging terminal 410, an overvoltage protection unit 421, and a dual charger 422 in a single chip form, a battery 430, and the battery. And a controller 440 for controlling the charging of the battery 430 by detecting and comparing the voltage of the battery 430 with the voltage applied to the charger 420.

The charging terminal 410 includes terminals TA and 401 for receiving power output from a power adapter (not shown), and terminals USB and 402 for receiving power output through a USB port.

Under the control of the controller 440, the charger 420 stabilizes a current having a predetermined voltage so as to charge the battery 430 using power applied through the TA terminal 411 and the USB terminal 412. Will print

The charger 420 is configured in a single chip form and includes an overvoltage protection unit 421 for shutting off the power when an overvoltage is applied through the terminals 411 and 412.

At this time, the charger 420 is provided with a kind of switching element that is switched by the charge control signal, a method of controlling the switching element will be described below with reference to the other drawings.

The overvoltage protection unit 421 is configured to have a breakdown voltage of at least about 28V for each power input, and outputs a stable voltage of about 5V through the overvoltage protection unit 421, thereby reducing the breakdown voltage of the dual charger 422. It can be reduced to about 7V. As a result, the manufacturing cost and size of the charger 420 may be reduced.

5 to 6 are diagrams for explaining the characteristics of the overvoltage protection unit 421. In particular, the characteristics of the overvoltage protection circuit of a path for processing power input through the USB port will be described.

In general, for USB data communication, the USB transceiver must be driven first, and thus, driving power through the Vbus terminal must be applied first, and then signals through the D + and D- terminals must be applied.

Therefore, when the application time of the Vbus power supply through the overvoltage protection unit 421 is delayed, that is, the power supply via the Vbus may be applied later than D + and D-, in which case the USB transceiver for USB communication may not be driven. As such, the overvoltage protection unit 421 should be designed in consideration of this.

That is, since the USB path side overvoltage protection circuit has a maximum USB voltage of 5.5V, when the reference voltage (OVLO: Over Voltage Lockout) is set to less than 5.5V, the USB data cable is inserted. Since the power applied through the Vbus is also cut off due to the instantaneous overshoot that occurs, D + and D- signals may be applied first, and a communication error may occur due to the late application of the Vbus power.

Therefore, in the present invention, by setting two reference voltages (OVLO1, OVLO2) for controlling the overvoltage protection unit through a controller, the second reference voltage is set to about 6V or more during the initial predetermined time (T1) that can cause overshoot The overvoltage is cut off by applying OVLO2, and after that time, the overvoltage is cut off by applying the first reference voltage OVLO1 set to less than 5.5V.

In other words, the overvoltage generated by the overshoot, although its voltage level is high, is so short that the overvoltage duration is not affected by the charger or USB transceiver burnout, so that the overshoot should be applied via Vbus during the overshoot. It is to prevent the power supply (power supply including overvoltage due to overshoot) from being cut off.

As described above, in the present invention, when the USB voltage is applied through the Vbus terminal, the second reference voltage OVLO2 is applied to the overvoltage protection circuit, thereby preventing the USB communication error by preventing the power supply from being cut off by the overvoltage due to the overshoot. After the predetermined time T1 of about several tens of ms, the first reference voltage OVLO1 is applied to block continuous overvoltage, thereby preventing burnout of the charger or the USB transceiver.

FIG. 6 is a diagram illustrating an example of a process of blocking the overvoltage when 28V overvoltage is continuously applied even after a predetermined time T1 after connecting the initial USB power cable.

Referring to Fig. 6, the overvoltage protection is performed when overvoltage of 5.5V or more is continuously applied even after a predetermined time T1 when an overshoot occurring when the initial USB cable is connected due to a failure of a USB type power adapter or the like. Blocking the applied overvoltage in the circuit prevents damage to the charger or the USB transceiver.

As described above, since the voltage input to the voltage detection ports 441 and 442 of the controller 440 is also a stable voltage of about 5V output through the overvoltage protection unit 421, the controller 440 burns out. The effect is to protect against the risk of burn out.

In addition, the controller 440 compares the voltage input through the voltage detection ports 441 and 442 with the voltage of the battery 430, and outputs a charging control signal to the charger 420 when the voltage of the battery is low. Control to apply a charging current to the battery 430.

Herein, the controller 440 may be any one of a power management module, an analog modem or a digital baseband modem of the portable terminal.

FIG. 7 is a view showing a brief switching circuit of a charger having an overvoltage protection function according to the present invention, in which a power supply path by a first switching element 712 having an overvoltage protection function is provided. 711 implements two paths by adding a bypass path.

For example, if the specification of the first switching device 711 is 0.2A, 28V, the second switching device 712 may be 1A, 28V, by detecting the applied voltage through the bypass path as described above It protects the USB transceiver of the controller and the port of the charger detector. The configuration having two paths including the bypass path may be applied to a power applying circuit through the TA terminal and a power applying circuit through the USB terminal.

On the other hand, the power management module (PMIC) is a module that can perform the function of the controller for controlling the charger, as shown in Figure 8, the USB transceiver (transceiver) for transmitting and receiving the charger 811 and USB data ( 812 can be built in.

At this time, the charger 811 is a dual charger that can be charged using the power output from the power adapter, and the power output through the USB port. At this time, the internal voltage is preferably designed to about 28V in consideration of the maximum power (about 24V) that can be output from the vehicle. Similarly, it is stable to design the internal voltage of the USB transceiver 812 at 28V.

However, when the overvoltage protection circuit 911 is further provided as shown in FIG. 9, it is obvious that the breakdown voltages of the charger 912 and the USB transceiver 913 can be designed lower.

In the above, preferred embodiments of the present invention have been described with reference to the accompanying drawings. Here, the terms or words used in the present specification and claims should not be construed as being limited to the common or dictionary meanings, but should be interpreted as meanings and concepts corresponding to the technical spirit of the present invention.

Therefore, the embodiments described in the specification and the drawings shown in the drawings are only the most preferred embodiment of the present invention, and do not represent all of the technical idea of the present invention, which can be replaced at the time of the present application It should be understood that there may be various equivalents and variations.

As described above, the present invention can standardize the power supply and the data communication to a single USB connector, thereby eliminating the need for a power cable and a power connector, thereby reducing the manufacturing cost and complexity of the terminal.

In addition, the present invention has an effect that can be protected from the risk of damage or burnout of the terminal by a USB type power adapter that is not properly supplied with the existing rated voltage.

In addition, the present invention has the effect of miniaturizing components by configuring the overvoltage protection circuit and the charger circuit in a single chip.

Claims (10)

An overvoltage protection unit that cuts off power when a predetermined voltage or more is applied and outputs only a power level below the predetermined voltage; A charger configured to perform battery charging using the power output through the overvoltage protection unit; And a controller for charging the battery by controlling the charger when the stable power is continuously applied through the overvoltage protection unit. The method of claim 1, The overvoltage protection unit, the charger or the controller is characterized in that at least two or more are composed of a single chip coupled to each other. The method of claim 1, wherein the controller, And a USB transceiver for transmitting and receiving USB data. The method of claim 1, wherein the power source, A portable terminal, characterized in that being applied through a portable adapter (TA) or universal serial bus (USB) port of the portable terminal. The method of claim 1, The breakdown voltage of the overvoltage protection unit is at least 24V or more. The method of claim 1, wherein the overvoltage protection unit, A portable terminal comprising at least two reference voltages for overvoltage blocking. The method of claim 6, wherein the overvoltage protection unit, A mobile terminal, characterized in that for over a period of time under control of a controller, an overvoltage is cut off by applying a high level reference voltage, and after that time, the overvoltage is cut off by changing to a low level reference voltage. The method of claim 1, wherein the controller, At least one of a power management module (Power Management IC), an analog modem or a digital modem (Analog or Digital Baseband Modem) of the portable terminal. The method of claim 1, wherein the charger, And at least two power paths in which a bypass mode is added by using at least two switching elements for preventing overvoltage. An overvoltage protection unit that receives power through a mobile adapter (TA) or a universal serial bus (USB) of the mobile terminal, cuts off a voltage of the power supply above a predetermined level, and outputs only a power below the predetermined level; And a charger configured to perform battery charging with the power output through the overvoltage protection unit under the control of a controller, in the form of a single chip.

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