KR20070081515A - The super protection circuit moudle - Google Patents

Abstract

A super PCM(Protection Circuit Module) is provided to extend usage time by increasing a battery discharge capacity through an EDLC and a current limit and boosting circuit as the ASIC(Application-specific integrated chip). A super PCM includes a current limiting circuit(30), a boosting circuit(40), and a charging unit(50). The current limiting circuit(30) is connected at one side of a battery protecting circuit(20) which is formed at an inner side of a battery pack, detects whether a voltage of a charged EDLC(Electric Double Layer Capacitor) is over a set value, charges the EDLC, and controls current not to exceed a set value. The boosting circuit(40) is connected at one side of the current limiting circuit(30), generates voltage over battery voltage, makes the voltage as DC, rectifies the voltage to charge the EDLC. The charging unit(50) charges the EDLC with energy accumulated in a coil through MOSFET 1, and 2 of the current limiting circuit(30).

Description

SuperPCM equipped with an ECC that increases battery discharge capacity and an ASC with current limiting and boosting circuits {THE SUPER PROTECTION CIRCUIT MOUDLE}

1 is a capacity characteristic graph according to a load consumption current discharge rate of a conventional battery;

2 is a block diagram showing a circuit configuration inside a battery pack for a mobile phone and a digital camera according to the present invention;

3 is an internal circuit diagram of a battery input unit of a mobile phone and a digital camera body according to the present invention;

4 is an internal circuit diagram installed inside a mobile phone and a digital camera main body using an EDLC and a current limiting and boosting circuit according to the present invention;

5 is an embodiment showing that the EDLC and the current limiting and boosting circuit according to the present invention are mounted on one side of a battery for a mobile phone by ASIC;

6 is a graph comparing the performance of the conventional and the present invention based on the continuous talk time of the mobile phone,

7 is a graph comparing the life cycle of the battery of the prior art and the present invention,

※ Brief description of drawing code ※

1: portable device 20: battery protection circuit

30: voltage limit circuit 40: boost circuit

50: filling part

The present invention provides an EDLC and an electric current for increasing battery discharge capacity on one side of a main body of a portable device such as a mobile phone or a digital camera or a secondary battery such as a lithium ion battery / lithium polymer battery, a fuel cell, or a sealed lead-acid battery. EDLC and current limit increase battery discharge capacity with the function of assisting the supply of instantaneous peak value discharge current, which is limited by the performance and discharge characteristics of the battery such as mobile lithium-ion battery, by installing it by limiting and boosting circuit. A booster circuit is related to a super PCM equipped with an ASIC.

In general, the lithium ion battery / lithium polymer battery among the above-mentioned mobile batteries is a battery pack which essentially incorporates the above battery protection circuit to maintain the life and performance by preventing overvoltage charging, low voltage discharge and overcurrent discharge. It is constructed and used.

The above batteries do not exhibit their rated capacity in accordance with the large and small current consumption of the main body of the portable device, that is, the increase in the discharge rate of the batteries.

In general, if the rated capacity of the secondary battery is indicated as, for example, 1,000 mAh as shown in FIG. 1, the total discharged electricity by discharging for 5 hours as a discharge condition, for example, a discharge current of 0.2C 200 mA × 5 hours = 1,000 mAh.

If the battery is discharged at 1,000 mA of discharge current of 1.0C under other conditions, it can be used for 1 hour by calculation, but the battery is consumed in 54 to 57 minutes, which is about 90 to 95%.

In other words, as the discharge amount is increased, the capacity is not exhibited up to 60-70% of the rated capacity. In addition, if the battery continues to be used in a high discharge rate, a problem of shortening the lifespan occurred.

The present invention devised to solve the above problems is that the above-mentioned batteries used in mobile devices can exhibit most of the rated capacity of 0.5C (discharge rate of 2 hours continuous DMB or total talk time 2 hours in the case of a mobile phone) or more The aim is to provide a circuit technology of EDLC and current limiting and boosting ASIC that allows the battery to fully exhibit its performance and extend the battery life cycle.

For the above purpose, the portable device and the battery pack configured by combining the EDLC and the current limiting / boost-up ASIC according to the present invention, the voltage of the EDLC for storing the energy of the battery in the battery protection circuit formed on one side of the battery reaches a set value. MOS FET acting as current switch, current mirror MOS FET to control charging with limited current, error amplifier to compare detected mirror current, external connection resistor to set current limit, reference voltage source, current Comparator of set value and current flowing, PWM circuit for boosting output voltage when battery voltage is lower than set voltage, MOS FET for driving inductor, Schottky Barrier diode rectifying generated pulse to DC voltage This is achieved by configuring the wiring with the EDLC to store.

Prior to describing the present invention, the term "super PCM" refers to a discharge characteristic of a battery due to a function of a protection circuit module (PCM) protection circuit module that protects performance and safety of a battery essential for a conventional lithium ion or lithium polymer battery. To control the high-capacity capacitor (EDLC) and its charging, such as a rooftop water tank that temporarily stores its energy by temporarily increasing its voltage to store its energy, or a capacitor that emits instantaneous high pressure on the camera strobe, to increase efficiency. It is referred to as super PCM in the present invention as a functional aggregate that results from the addition of a current limiting circuit for high performance.

With reference to the accompanying drawings, preferred embodiments of the present invention described above will be described in detail below.

Figure 2 relates to a block diagram according to the invention, Figure 3 relates to the internal circuit diagram of the battery input unit of the mobile phone, digital camera body according to the invention, Figure 4 is an EDLC and current limiting and boosting circuit according to the present invention The present invention relates to an internal circuit diagram employed in a mobile phone and a digital camera main body, and FIG. 5 relates to an exemplary embodiment showing that an EDLC and a current limiting / boosting ASIC according to the present invention are mounted on one side of a battery for a mobile phone. 6 relates to a graph comparing the performance of the conventional invention and the present invention based on the continuous talk time of the mobile phone, and FIG. 7 relates to a graph comparing the life cycle of the battery of the prior art and the present invention.

As shown in Figure 2 is a circuit diagram of the internal circuit of the battery input unit of the mobile phone, the digital camera body according to the present invention, which is the inside of the main body of the mobile device, such as a mobile phone, digital camera or the like lithium ion battery (10) The battery protection circuit 20 is configured at one side, and the current protection 30 and the booster circuit 40 are formed at one side of the battery protection circuit 20, and the current limit 30 and the booster circuit 40 are at one side of the battery protection circuit 20. EDLC which is the filling part 50 is connected.

Here, EDLC has a characteristic capable of slow charging and rapid peak discharge, and focuses on this, and constitutes a circuit for charging EDLC with a constant current or less from a battery.

3 is an internal circuit diagram of a battery input unit of a mobile phone and a digital camera main body according to the present invention, which includes a current protection circuit in a battery protection circuit 20 formed on one side of a battery 10 such as a lithium ion battery used in a portable device. 30), the booster circuit 40, and the filling unit 50.

First, the current limiting circuit 30 is composed of a thermal measurement comparator 31, an OR gate 32, MOSFETs 1 and 2, an error amplifier 33, and a current detection comparator 34 in a chip.

The chip internal temperature measurement signal from the chip internal temperature sensor attached to one side of the battery is introduced into the + terminal, and the internal temperature measurement comparator 31 for comparing and analyzing each other by introducing a reference set value of 150 ° C. into the terminal. Is composed.

If only one of the terminal A value to which the output value outputted through the chip internal temperature measuring comparator 31 is input and the terminal B value to which the current value detected through the current detection comparator is inputted are “1”, the result is “1”. If all are "0", the OR gate 32 whose result is "0" is connected.

The output side of the OR gate 32 is connected to the gate terminal of the MOSFET 1 which serves as a current switch to control charging with a limited current until the voltage of the EDLC storing the cell energy reaches a set value.

The MOSFET 2 is connected to the primary side of the inductor to one side of the output value of the OR gate 32.

One side of the gate terminal of the MOSFET 1 is connected to the negative terminal, and one side of the source terminal of the MOSFET 2 is connected to the positive terminal to serve to control charging by detecting whether the voltage of the charged EDLC exceeds a set value. The error amplifier 33 is connected and configured

A current detection comparator 34 which serves to prevent the source terminal of MOSFET 3 connected to the output terminal of the error amplifier 33 from being connected to the + terminal, and the I _SET value of 1.24 V is connected to the-terminal so that it does not flow from the battery beyond the set current. ) Is connected and configured.

This current detection comparator 34 is detected by the current mirror (Current Mirror) effect of the MOSFET 1, 2.

Hereinafter, the current mirrors of the MOSFETs 1 and 2 according to the present invention will be described.

In the present invention, as shown in Fig. 3, the current mirror is composed of two incremental MOSFETs 1 and 2 having the same threshold voltage Vt but different (W / L) ratios.

MOSFET 1 is driven with reference current I _REF , output current I _O is taken from the drain of MOSFET 2, and MOSFET 2 must operate in the saturation region.

I _REF of Q1 is obtained from the following equation (1).

Here, K1 represents the mobility of electrons and the capacitance of the SiO ₂ layer of the gate.

V _GS is a gate-source voltage corresponding to the drain current of I _REF , and since MOSFETs 1 and 2 are connected in parallel, they have the same V _GS value.

Therefore, I ₀ is obtained from the following equation.

In Equations 1 and 2

Here, since K1 and K2 are elements on the same substrate, the width W and the length L of each channel can be expressed by Equation 4 below. In other words,

Thus, in an ideal case, I _O is a multiple of I _REF , and the value of the multiple is determined by the shape of the device, but in practice the I _O value of Equation 4 is given only when the drain voltage of MOSFET 2 is equal to V _GS. . In other words, when the drain voltage changes, I _O changes due to the finite output resistance ro of MOSFET 2.

Using the current mirror characteristics of the MOSFETs 1 and 2, even when the low voltage (normally low battery warning voltage starts) region close to the end of discharge of the battery is boosted and charged to the EDLC, the remaining charge of the battery reaches the bottom. Until it becomes available.

Next, the booster circuit 40 will be described. The booster circuit 40 is composed of a Schottky barrier diode, a PWM circuit, and a MOSFET 4.

The Schottky barrier diode is connected to one side of the source terminal of MOSFET 2, which drives MOSFET 2 to store instantaneous energy (less than 10uS) in the inductor and then through the Schottky barrier diode in the next cycle. DC-type rectification is performed to charge the EDLC. The Schottky gate electrode is directly attached to the N-type semiconductor to prevent reverse voltage at the contact surface between the metal and the semiconductor (short key barrier). In the present invention, the diode is used for power rectification of low voltage and high current, which reduces the forward voltage as compared with the general rectifier diode, thereby reducing the loss.

MOSFET 4 is connected to one side of the Schottky barrier diode input terminal, and a PWM circuit is configured to one gate terminal of the MOSFET 4.

The PWM circuit is composed of an inverter 41, a controller 42, a current comparator 43, a shutdown unit 44, and an oscillator (OSC) 45 to generate a voltage higher than the battery voltage.

The inverter 41 serves to convert DC power into AC power.

The controller 42 resets the current so that the current no longer flows to the load when the voltage reaches the voltage and exceeds the current limit.

The current comparator 43 senses the external resistors R1 and R2 to apply the current value charged to the EDLC to the + terminal, and the reference voltage source 43a is connected to the-terminal to set the current limit value I _SET .

Shutdown section 44 is to allow the PWM circuit to be normally driven by a reset when shut down due to overcurrent when using a mobile device such as a GSM / CDMA mobile phone or a digital camera. Exclusive-OR gate 44a is connected to one side.

The Exclusive-OR gate 44a has a shutdown set point at the + terminal, and-an option for operating a mobile device such as a mobile phone or a digital camera such as a GSM / CDMA method at the + terminal. 1 ", the output also becomes" 1 ". However, if both inputs are "0" or both inputs are "1", set the output to be "0" to cause a ShutDown.

The boost circuit 40 configured as described above operates like a normal switching regulator in a PWM circuit, and the generated signal drives MOSFET 1 to store instantaneous energy (less than 10 uS) in the inductor, and then, in the next cycle, the Schottky Barrier DC through the diode is charged to the EDLC. When the boosted output voltage (ie, the charge voltage of the EDLC) reaches the set output voltage, the output voltage is kept constant by reducing the duty (a ratio of duty on time) of the PWM.

Next, the filling unit 50 is installed at one side of the lower end of the coil (Inductor), and charges the energy accumulated in the coil through the current mirror of the PWM circuit, MOSFET1,2 in an electric double layer capacitor (EDLC). It is configured to be.

The driving process of the filling unit will be described in detail. Each of the signals driven by the error amplifier 33, the current detection comparator 34, and the PWM circuit is inputted to an OR gate, and a logical result is displayed at an output.

The output of the OR gate turns on the MOSFET 1 for charging the battery power to the coil (inductor). When the oscillation frequency of the OSC enters the OFF region, MOSFET1 is turned off and the energy accumulated in the coil is charged to the electric double layer storage battery EDLC through FET2. By repeating this operation periodically, the ON TIME of the MOSFET 1 is automatically adjusted by continuously monitoring whether the output voltage exceeds the specified value or the battery current consumption exceeds the limit.

4 is a mobile phone using an EDLC and a current limiting and boosting circuit according to the present invention, and an internal circuit diagram installed inside a digital camera body, and FIG. 5 is a mobile phone ASIC using an EDLC and a current limiting and boosting circuit according to the present invention. As one embodiment showing that the battery is mounted on one side, which is the current limiting circuit, the boosting circuit is ASIC is composed of a one-chip 100, is installed inside the mobile phone, digital camera body, thereby improving the performance of the battery The life can be extended.

Hereinafter, a comparison experiment between the use time and life cycle of a continuous communication mode, such as a super PCM equipped with an EDLC and an electric current limiting / boosting circuit with an ASIC that increases the battery discharge capacity according to the present invention and an existing battery pack, is performed. saw.

Figure 6 is a graph comparing the use time of the mobile phone by adding the circuit of the prior art and the present invention based on the operating time. Here, A1 shows the peak value of the no-load battery voltage mounted with the conventional pure battery, A2 shows the battery voltage at the time of RF power transmission when using the conventional pure battery, and B1 shows the EDLC according to the present invention. The peak value of the super PCM battery voltage with the current limiting and boosting ASIC is shown, and B2 is the output voltage of the timing at which the RF is not transmitted when using the EDLC according to the present invention and the super PCM with the current limiting and boosting ASIC. Terminal voltage) is shown.

At this time, as a result of comparing A1 and B1, A2 and B2, the mobile phone operating time of the battery voltage equipped with a conventional pure battery between 3.3V and 3.4V was 90 minutes, whereas EDLC and current limiting and boosting according to the present invention were used. The battery life of an ASIC-equipped cell phone is 123 minutes, which is about 35% longer.

7 is a graph comparing the battery life cycle of the prior art and the present invention. The battery used in combination with the EDLC according to the present invention and the current limiting and boosting ASIC is repeatedly charged and discharged to the EDLC periodically so that the peak power is consumed by the EDLC rather than the battery. Since the guaranteed life characteristics are conditions under low current limited in the specification table, it is not guaranteed for the current consumption of about 2.5A, which is the peak power of a mobile phone such as GSM / CDMA system. Even if the number is 500 times, the battery capacity is about 620mAh or more and about 75%. However, when only a conventional pure battery is used, the battery capacity is 50% or less in 300 cycles.

In other words, the battery equipped with the EDLC according to the present invention and the ASIC with the current limiting / boosting circuit can be seen that the life of the battery is longer than that of the conventional pure battery.

As described above, when the EDLC according to the present invention and the current limiting / boosting circuit are installed as ASICs, the battery discharge capacity is increased, so that the use time of a mobile phone call mode is extended by about 35%, and the battery life is 150. It is extended by more than%, and is composed of a modular inside the battery pack, it can be easily used in the existing mobile phone batteries, the compatibility is excellent, and the cost saving effect.

Claims (4)

Connected to one side of the battery protection circuit 20 formed inside the main body of the mobile device or inside one side of the battery pack 10 such as a lithium ion battery to detect whether the charged EDLC voltage has exceeded the set value and charge the battery. A current limiting circuit 30 which controls not to flow from the battery; A booster circuit 40 connected to one side of the current limiting circuit 30 to generate a voltage higher than the battery voltage to be DC to rectify and charge the EDLC; The charging unit 50 for charging the energy accumulated in the coils through the MOSFETs 1 and 2 of the current limiting circuit 30 in an electric double layer (EDLC) capacitor (ASLC) is ASIC and is composed of one chip. Super PCM with ASIC integrated EDLC which increases battery discharge capacity and current limit and boost circuit. According to claim 1, the current limiting circuit 30 is a chip temperature measurement signal introduced from the chip temperature measurement sensor attached to the battery side is introduced into the + terminal, the reference set value of 150 ℃ is introduced into the terminal-to analyze each other And a chip A measurement comparator 31 for comparison, the terminal A to which the output value outputted through the chip thermal measurement comparator 31 is inputted, and the terminal B value to which the current value detected through the current detection comparator 34 is inputted. If either one is "1", the result is "1", and if all are "0", the OR gate 32 which is the result is "0" is connected, and the charge energy of the battery is stored to the output side of the OR gate 32. The gate terminal of MOSFET 1, which acts as a current switch, is connected to control charging with limited current until the voltage of the EDLC reaches the set value, and the MOSFET 2 for driving the inductor is driven by the output value of the OR gate 32. Connected to the primary side of One side of the gate terminal of the MOSFET 1 is connected to the negative terminal, and one side of the source terminal of the MOSFET 2 is connected to the positive terminal to operate to control charging by detecting whether the voltage of the charged EDLC exceeds a set value. The error amplifier 33 is connected, the source terminal of MOSFET 3 connected to the output side of the error amplifier 33 is connected to the + terminal, and the I _SET value of 1.24V is connected to the-terminal so that it does not flow from the battery beyond the set current. Super PCM equipped with an EDLC and an electric current limiting / boosting circuit for increasing the battery discharge capacity, characterized in that the current detection comparator 34 is configured to be connected. 3. The current detection comparator 34 is detected by the current mirror effect of the MOSFETs 1 and 2, and the EDLC and the current limiting / boosting circuit for increasing the battery discharge capacity are ASIC. Comes equipped with a super PCM. 2. The boost circuit 40 operates in the same way as a conventional switching regulator in a PWM circuit so that the generated signal drives MOSFET 1 to store instantaneous (10 uS or less) energy in the inductor and then cycles. DC is charged through the Schottky Barrier diode at the EDLC, and when the boosted output voltage (ie, the charge voltage of the EDLC) reaches the set output voltage, the output voltage is reduced by reducing the duty of the PWM (a ratio of duty on time). A super PCM equipped with an ASIC integrated EDLC and a current limiting / boosting circuit for increasing battery discharge capacity, characterized by being configured to be kept constant.

Images