CN201204479Y - Lithium battery charger control integrated circuit and its charging indication control circuit - Google Patents

Abstract

The utility model discloses a lithium battery charger control integrated circuit and a charging indication control circuit for avoiding misoperation of charging indication. The charging indication control circuit of the present invention includes a power input terminal (VDD), a ground terminal, a voltage divider (T), a voltage comparator (OP2), and a Resistor (R27), there are two groups of resistors (R28, R10, R29) connected in parallel between the voltage divider (T) and the grounding terminal. The resistance values of each resistor are equal, and the inverting input of the voltage comparator (OP2) The terminal (IN-) is connected to the voltage divider terminal (T), the voltage of the non-inverting input terminal (IN+) is equal to the reference voltage, and the output terminal (OUT) is connected to the charging indicator circuit; when the lithium battery is put into the charger and the power input When the terminal (VDD) is not powered, the voltage of the non-inverting input terminal (IN+) is greater than the voltage of the inverting input terminal (IN-), the output terminal (OUT) outputs a high level, and the charging indicator is off; otherwise, the charging indicator is on.

Description

Lithium battery charger control integrated circuit and its charging indication control circuit

technical field

The utility model relates to a lithium battery charger control integrated circuit and a charging indication control circuit thereof.

Background technique

Currently, rechargeable lithium-ion batteries are commonly used as power supplies in electronic products such as mobile phones, and such lithium-ion batteries need to be charged by a charger. At present, most lithium battery chargers use a variety of dedicated control integrated circuits (IC) and various sampling circuits. In the lithium battery charging control circuit using P-MOSFET as the control tube, due to the parasitic diode of the P-MOSFET itself, parasitic effects will occur, so that when the power input terminal VDD is first installed with the battery to be charged but not powered on, the battery The voltage will be added to the power input terminal VDD through the parasitic diode, so that the internal circuit of the IC will work and the charging indicator light will flash.

Utility model content

The technical problem to be solved by the utility model is to overcome the deficiencies of the prior art and provide a charge indication control circuit of a lithium battery charger control integrated circuit that avoids misoperation of the charge indication.

In addition, the utility model also provides a lithium battery charger control integrated circuit using the charging indication control circuit.

The technical solution adopted by the charging indication control circuit of the lithium battery charger control integrated circuit of the utility model is: the charging indication control circuit of the lithium battery charger control integrated circuit of the utility model includes a power input terminal, a ground terminal, a voltage divider terminal, a voltage A comparator, a resistor is connected between the power supply input terminal and the voltage dividing terminal, and two groups of resistors connected in parallel are connected between the voltage dividing terminal and the ground terminal, and the resistance values of each of the resistors are equal , the inverting input terminal of the voltage comparator is connected to the voltage dividing terminal, the voltage of the non-inverting input terminal is equal to the reference voltage, and the output terminal is connected to the charging indicator circuit; when the lithium battery is put into the charger and the power input When the terminal is not energized, the voltage of the non-inverting input terminal is greater than the voltage of the inverting input terminal, the output terminal outputs a high level, and the charging indicator light is off; when the power supply input terminal is energized, the voltage of the inverting input terminal If it is higher than the voltage of the non-inverting input terminal, the output terminal outputs a low level, and the charging indicator light is on.

The technical solution adopted by the lithium battery charger control integrated circuit of the utility model is: the lithium battery charger control integrated circuit of the utility model includes a charging indication control circuit, and the charging indication control circuit includes a power input terminal, a ground terminal, and a voltage dividing terminal , a voltage comparator, a resistor is connected between the power supply input terminal and the voltage divider, two groups of resistors connected in parallel are connected between the voltage divider and the ground terminal, and the resistance value of each resistor is are equal, the inverting input of the voltage comparator is connected to the voltage divider, the voltage of the non-inverting input is equal to the reference voltage, and the output is connected to the charging indicator circuit; when the lithium battery is put into the charger and the When the power input terminal is not energized, the voltage of the non-inverting input terminal is greater than the voltage of the inverting input terminal, the output terminal outputs a high level, and the charging indicator light is off; when the power input terminal is energized, the inverting input terminal The voltage at the terminal is greater than the voltage at the non-inverting input terminal, the output terminal outputs a low level, and the charging indicator light is on.

The beneficial effects of the utility model are: since the charging indication control circuit of the utility model includes a power input terminal, a ground terminal, a voltage divider, and a voltage comparator, there is a connection between the power input terminal and the voltage divider resistor, two groups of resistors connected in parallel are connected between the voltage dividing terminal and the grounding terminal, the resistance values of each of the resistors are equal, and the inverting input terminal of the voltage comparator is in phase with the voltage dividing terminal. Connected, the voltage of the non-inverting input terminal is equal to the reference voltage, and the output terminal is connected to the charging indicator circuit; when the lithium battery is put into the charger and the power input terminal is not powered, the voltage of the non-inverting input terminal is greater than that of the inverting input terminal voltage, the output terminal outputs a high level, and the charging indicator light is off; when the power input terminal is powered on, the voltage of the inverting input terminal is greater than the voltage of the non-inverting input terminal, and the output terminal outputs a low level, charging The indicator light is on, and the utility model has utilized the fact that the power input terminal of the battery charger is always greater than the voltage of the lithium battery to control the work of the charging indicator circuit. The charging voltage of the general lithium battery charger is 4.2V. When the voltage is 4.2V, if the voltage at the voltage dividing terminal is 1.68V, when the reference voltage Vref=1.68V is used, the voltage at the non-inverting input terminal is equal to 1.68V, because the voltage at the power supply input terminal is always greater than 4.2V , so when the lithium battery is put into the charger and the power input terminal is not powered on, the voltage of the non-inverting input terminal is greater than the voltage of the inverting input terminal, and the output terminal outputs a high level so that the charging indicator light goes out and does not Flashing; when the power input terminal is energized, the voltage of the inverting input terminal is always greater than the voltage of the non-inverting input terminal, and the output terminal outputs a low level to make the charging indicator light on, so the utility model can avoid charging indication error action.

Description of drawings

Fig. 1 is the circuit schematic diagram of the charging indication control circuit of the lithium battery charger control integrated circuit of the utility model;

Fig. 2 is the circuit schematic diagram of the utility model lithium battery charger control integrated circuit;

Fig. 3 is a schematic diagram of an application connection of the control integrated circuit of the lithium battery charger of the present invention.

Detailed ways

As shown in Figure 1, Figure 2 and Figure 3, the lithium battery charger control integrated circuit of the present invention includes a voltage sampling resistor network 1, a charging indication control circuit 2, a short circuit protection circuit 3, a polarity switch control circuit 4 and a constant A current constant voltage control circuit, the charging indication control circuit 2 includes a power supply input terminal VDD, a ground terminal, a voltage divider T, and a voltage comparator OP2, and a resistor is connected between the power supply input terminal VDD and the voltage divider T R27, two groups of resistors connected in parallel with each other are connected between the voltage dividing terminal T and the ground terminal (one group is R28, and the other group is R10, R29 connected in series), each of the resistors R10, R27, R28, R29 The resistance values of the voltage comparator OP2 are all equal, the inverting input terminal IN of the voltage comparator OP2 is connected to the voltage dividing terminal T, the voltage of the non-inverting input terminal IN+ is equal to the reference voltage, and the output terminal OUT is connected to the charging indicator circuit; When the lithium battery is put into the charger and the power input terminal VDD is not powered on, the voltage of the non-inverting input terminal IN+ is greater than the voltage of the inverting input terminal IN-, the output terminal OUT outputs a high level, and the charging indication The light is off; when the power supply input terminal VDD is energized, the voltage of the inverting input terminal IN- is greater than the voltage of the non-inverting input terminal IN+, the output terminal OUT outputs a low level, and the charging indicator light is on.

The utility model utilizes the fact that the power input end of the battery charger is always greater than the voltage of the lithium battery to control the work of the charging indicator circuit. The charging voltage of the general lithium battery charger is 4.2V. When the VDD voltage of the power input end is When 4.2V, the voltage of the voltage dividing terminal T is 1.68V, when the reference voltage Vref=1.68V is adopted, the voltage of the non-inverting input terminal IN+ is equal to 1.68V, because the voltage of the power supply input terminal VDD is always greater than 4.2V, so when the lithium battery is put into the charger and the power input terminal VDD is not powered on, the voltage of the non-inverting input terminal IN+ is greater than the voltage IN- of the inverting input terminal, and the output terminal OUT outputs a high voltage The level makes the charging indicator light off, which effectively avoids the phenomenon that the charging indicator light flickers due to the parasitic effect of the P-MOSFET; when the power input terminal VDD is powered on, the voltage of the inverting input terminal IN- is always greater than the specified The voltage of the non-inverting input terminal IN+ is described, and the output terminal OUT outputs a low level to make the charging indicator light on, so the utility model can avoid charging indication malfunctions.

In addition, the voltage value of the voltage dividing terminal T has nothing to do with the specific resistance value and accuracy of each of the resistors R10, R27, R28, and R29, and it is only necessary that each of the resistors be of the same specification to accurately determine the sampling voltage. The voltage is conveniently implemented in an integrated circuit, so the utility model is easy to manufacture, accurate in sampling, and accurate in charging process control.

The lithium battery charger control integrated circuit of the utility model has a power supply input terminal VDD, a ground terminal GND, lithium battery positive and negative terminals BT+, BT-, an external capacitor port CBP, and a power supply indicating port L3, a charging indicating port L2, and a saturation indicating port L1, so there are 8 external pins after packaging, and the peripheral circuit is very simple, the peripheral components are few, the degree of integration is high, and it is easy to promote and use.

The utility model can be widely used in the lithium battery charging field.

Without departing from the inventive idea of the present utility model, all equivalent changes made by using the specification and drawings of the present utility model are all included in the scope of claims of the present utility model.

Claims (2)

1, a kind of charging indication control circuit of lithium battery charger controlled integrated circuit, it is characterized in that: comprise power input (VDD), earth terminal, divide pressure side (T), voltage comparator (OP2), described power input (VDD) and be connected to resistance (R27) between pressure side (T) in described minute, described minute pressure side (T) with described earth terminal between be connected to two groups of resistance (R28 that are connected parallel with one another, R10, R29), each described resistance (R10, R27, R28, R29) resistance value all equates, the inverting input (IN-) of described voltage comparator (OP2) with described minute pressure side (T) be connected, the voltage of in-phase input end (IN+) equals reference voltage, output (OUT) is connected with charging indicator light circuit; When lithium battery is put into charger and described power input (VDD) when not switching on, the voltage of described in-phase input end (IN+) is greater than the voltage of described inverting input (IN-), described output (OUT) output high level, and charging indicator light goes out; When described power input (VDD) was switched on, the voltage of described inverting input (IN-) was greater than the voltage of described in-phase input end (IN+), described output (OUT) output low level, and charging indicator light is bright.

2, a kind of lithium battery charger controlled integrated circuit, comprise charging indication control circuit, it is characterized in that: described charging indication control circuit comprises power input (VDD), earth terminal, divide pressure side (T), voltage comparator (OP2), described power input (VDD) and be connected to a resistance (R27) between pressure side (T) in described minute, described minute pressure side (T) with described earth terminal between be connected to two groups of resistance (R28 that are connected parallel with one another, R10, R29), each described resistance (R10, R27, R28, R29) resistance value all equates, the inverting input (IN-) of described voltage comparator (OP2) with described minute pressure side (T) be connected, the voltage of in-phase input end (IN+) equals reference voltage, output (OUT) is connected with charging indicator light circuit; When lithium battery is put into charger and described power input (VDD) when not switching on, the voltage of described in-phase input end (IN+) is greater than the voltage of described inverting input (IN-), described output (OUT) output high level, and charging indicator light goes out; When described power input (VDD) was switched on, the voltage of described inverting input (IN-) was greater than the voltage of described in-phase input end (IN+), described output (OUT) output low level, and charging indicator light is bright.

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