CN206850467U

CN206850467U - A kind of anti-reverse charging charging circuit of Intelligent bracelet

Info

Publication number: CN206850467U
Application number: CN201720451639.0U
Authority: CN
Inventors: 薛磊
Original assignee: Guangdong Appscomm Digital Technology Co Ltd
Current assignee: Guangdong Appscomm Digital Technology Co Ltd
Priority date: 2017-04-27
Filing date: 2017-04-27
Publication date: 2018-01-05
Anticipated expiration: 2027-04-27

Abstract

It the utility model is related to a kind of anti-reverse charging charging circuit of Intelligent bracelet, the circuit includes single lithium battery Charge Management IC, charge input line parallel after one electric capacity C2 of negative pole charging input line concatenation with positive pole, together it is linked into the power input pin VIN of the Charge Management IC, it is characterized in that, a NMOS tube is set between the input and the electric capacity C2 of negative pole charging input line, the drain electrode of the NMOS tube connects the input of the negative pole charging input line, after the control pole connection resistance R5 of the NMOS tube, and access positive pole charging input line, the source electrode of the NMOS tube and the capacitance connection, line-to-ground between the source electrode of the NMOS tube and the electric capacity.The circuit can solve the problems, such as reversely charging and pressure drop well, so as to get the voltage up to charging IC ends maintains essentially in 5V.

Description

A kind of anti-reverse charging charging circuit of Intelligent bracelet

Technical field

It the utility model is related to a kind of charging circuit, and in particular to a kind of charging circuit of anti-reverse charging pressure drop prevention.

Background technology

At present, in intelligent wearable device, Charge Management IC typically uses single lithium battery Charge Management IC SGM4056 is managed, and plus suitable charging circuit, as shown in Figure 1, to be charged, the charging that accompanying drawing 1 is 5V is electric Road.There is a very big hidden danger in the circuit, after charging connector is reversed, charging IC SGM4056 easily burn, and hold Easily burn late-class circuit.

In design, applicant accesses a diode in charging input end（Such as accompanying drawing 2）, to solve asking for anti-reverse charging Topic.But through overtesting, after finding access diode, charge efficiency is very low, or even can not be wearable substantially sometimes Equipment（Such as intelligent watch and Intelligent bracelet）Charging, to find out its cause, SGM4056 4.5 ~ 6.5V of normal operational voltage value is found, If using the counnter attack charging circuit of diode, because pressure drop in itself be present in diode（Germanium tube 0.3-0.4V, silicone tube 0.5-0.7V）, So, or cause the voltage at arrival charging IC ends to be less than 4.5V, or slightly larger than 4.5V, so result in the feelings that can not be charged Condition.

Utility model content

The utility model proposes a kind of charging circuit of anti-reverse charging pressure drop prevention, the circuit to solve above-mentioned technical problem Can solve the problems, such as reversely charging and pressure drop well, so as to get the voltage up to charging IC ends maintains essentially in 5V.

A kind of anti-reverse charging charging circuit, the circuit include single lithium battery Charge Management IC, negative pole charging input line string The input line parallel that charged with positive pole after an electric capacity C2 is connect, is together linked into the power input pin of the Charge Management IC（VIN）, its It is characterised by, a NMOS tube, the NMOS tube is set between the input and the electric capacity C2 of negative pole charging input line Drain electrode connect the input of negative pole charging input line, after the control pole connection resistance R5 of the NMOS tube, and access institute State positive pole charging input line, the source electrode of the NMOS tube and the capacitance connection, the source electrode of the NMOS tube and the electric capacity it Between line-to-ground.

Further, the single lithium battery Charge Management IC is SGM4056.

Further, the GND pin of the single lithium battery Charge Management IC SGM4056 are grounded, after EN pin series resistors R6 It is grounded, is grounded, is grounded after IMIN pin series resistors R8, BAT pin connect anode after IREF pin series resistors R7.

Further, the resistance R6 resistances are that 10k Ω, the resistance R7 are 108 k Ω to 132k Ω, the resistance R8 For 675 k Ω to 825k Ω.

Further, the electric capacity C2 is that 4.7 μ F, the resistance R5 are 10 k Ω.

Further, the NMOS tube is ME1702.

Pass through above-mentioned technical proposal, charging anti-reverse charging is realized, avoid charger is reversed from burning bracelet equipment, and substantially not It can be depressured.

Brief description of the drawings

Fig. 1 is the charging circuit of prior art.

Fig. 2 is to add the charging circuit after diode.

Fig. 3 is charging circuit of the present utility model.

Embodiment

Example embodiment is described more fully with referring now to accompanying drawing.However, example embodiment can be with a variety of shapes Formula is implemented, and is not understood as limited to example set forth herein；On the contrary, these embodiments are provided so that the utility model will More fully and completely, and by the design of example embodiment comprehensively it is communicated to those skilled in the art.Accompanying drawing is only this The schematic illustrations of utility model, it is not necessarily drawn to scale.Identical reference represents same or similar in figure Part, thus repetition thereof will be omitted.

In addition, described feature, structure or characteristic can be incorporated in one or more implementations in any suitable manner In mode.In the following description, there is provided many details are so as to providing the abundant reason to embodiment of the present utility model Solution.It will be appreciated, however, by one skilled in the art that the technical solution of the utility model can be put into practice and omit the specific detail In it is one or more, or other methods, constituent element, device, step etc. can be used.In other cases, do not show in detail Go out or describe known features, method, apparatus, realization or operation cause each side of the present utility model to avoid that a presumptuous guest usurps the role of the host Thicken.

As described in Figure 1, single lithium battery Charge Management IC SGM4056, can be to charging current when needing 5V to charge It is configured, charging current sets IREF=12200/R7（Unit mA）, R7 is the resistance for being serially connected in IREF pin, is grounded after concatenation, According to the setting of charging current 120k Ω are calculated, the deviation that can have 1%, charge cutoff electric current is set in the resistance of resistance IMIN=11000/R8（Unit mA）, R8 is the resistance for being serially connected in IMIN pin, is grounded after concatenation, and the resistance of resistance is cut according to charging Only electric current is set, and 750k Ω is calculated, the deviation that can have 1%.SGM4056 pin 5（GND）Ground connection, pin 4（EN）Connect It is grounded after entering resistance R6, R6 resistance is 10k Ω, pin 8（BAT）Connect anode.In charging end, negative pole charging input line string The input line parallel that charged with the positive pole after an electric capacity C2 is connect, is together linked into Charge Management IC power input pin（VIN）, bear The line-to-ground that pole is charged between input line and the electric capacity.

It is not particularly evident to be distinguished due to current charging head both positive and negative polarity, and therefore, very big probability has both positive and negative polarity reversal connection Situation, now, when reversal connection, easily burn Charge Management IC and late-class circuit.

As shown in Figure 2, applicant is designed by the way of diode first for anti-reverse charging, is charged and is inputted in negative pole A diode is concatenated between line and electric capacity C2, there is the presence of diode, once there is the situation of reversal connection, whole circuit will not lead to Electricity, therefore avoid the situation of circuit burnout.But after connecting diode, there is a situation where not filling electricity thereupon.By Experiment, after finding access diode, charge efficiency is very low, or even can not be wearable device substantially sometimes（Such as intelligence Wrist-watch and Intelligent bracelet）Charging, to find out its cause, SGM4056 4.5 ~ 6.5V of normal operational voltage value is found, if using two poles The counnter attack charging circuit of pipe, because diode has pressure drop in itself（Germanium tube 0.3-0.4V, silicone tube 0.5-0.7V）, so, or cause The voltage for reaching charging IC ends is less than 4.5V, or slightly larger than 4.5V, so results in situation about can not charge.

As shown in Figure 3, in order to can anti-reverse charging again ensure input voltage charging IC effective voltage section, application People devises the circuit of an anti-reverse charging low pressure drop, and the circuit includes single lithium battery Charge Management IC, negative pole charging input Charge input line parallel after one electric capacity C2 of line concatenation with the positive pole, is together linked into the power input pin of the Charge Management IC （VIN）, it is characterised in that a NMOS tube, institute are set between the input and the electric capacity C2 of negative pole charging input line State draining for NMOS tube and connect the input of the negative pole charging input line, after the control pole connection resistance R5 of the NMOS tube, And access the positive pole charging input line, the source electrode of the NMOS tube and the capacitance connection, the source electrode of the NMOS tube and institute State the line-to-ground between electric capacity.The single lithium battery Charge Management IC is SGM4056.The GND pin of the SGM4056 connect Ground, it is grounded after EN pin series resistors R6, is grounded after IREF pin concatenation R7, is grounded after IMIN pin concatenation R8, the BAT pin connect battery Positive pole.The electric capacity C2 is that 4.7 μ F, the resistance R5 are 10 k Ω.The NMOS tube is ME1702.

When external power supply normally accesses, 5V_CHARGE+ and 5V_CHARGE- voltages input for 5V, and NMOS tube is normal Conducting, NMOS Rds is 35 bold and unconstrained Europe, and charging current 100mA, NMOS Vds voltage differences are 3.5mV, and charge IC SGM4056 charging voltage is 5-0.0035=4.9965V, and pressure drop is very small, effective model of the charging voltage in Charge Management IC Enclose.

Finally it should be noted that：Various embodiments above is only to illustrate the technical solution of the utility model, rather than it is limited System；Although the utility model is described in detail with reference to foregoing embodiments, one of ordinary skill in the art should Understand：It can still modify to the technical scheme described in foregoing embodiments, either to which part or whole Technical characteristic carries out equivalent substitution；And these modifications or replacement, the essence of appropriate technical solution is departed from this practicality newly The scope of each embodiment technical scheme of type.

Claims

1. a kind of anti-reverse charging charging circuit of Intelligent bracelet, the circuit includes single lithium battery Charge Management IC, negative pole charging Charge input line parallel after one electric capacity C2 of input line concatenation with positive pole, is together linked into the power input pin of the Charge Management IC VIN, it is characterised in that a NMOS tube is set between the input and the electric capacity C2 of negative pole charging input line, it is described Draining for NMOS tube connects the input of the negative pole charging input line, after the control pole connection resistance R5 of the NMOS tube, and Access positive pole charging input line, the source electrode of the NMOS tube and the capacitance connection, the source electrode of the NMOS tube and the electric capacity Between line-to-ground.

A kind of 2. anti-reverse charging charging circuit of Intelligent bracelet according to claim 1, it is characterised in that the single-lithium-battery Pond Charge Management IC is SGM4056.

A kind of 3. anti-reverse charging charging circuit of Intelligent bracelet according to claim 2, it is characterised in that the single-lithium-battery Pond Charge Management IC SGM4056 GND pin are grounded, and are grounded after EN pin series resistors R6, are grounded after IREF pin series resistors R7, It is grounded after IMIN pin series resistors R8, BAT pin connect anode.

A kind of 4. anti-reverse charging charging circuit of Intelligent bracelet according to claim 3, it is characterised in that the resistance R6 resistances It is that 108 k Ω to 132k Ω, the resistance R8 are 675 k Ω to 825k Ω to be worth for 10k Ω, the resistance R7.

5. the anti-reverse charging charging circuit of a kind of Intelligent bracelet according to claim 1, it is characterised in that the electric capacity C2 is 4.7 μ F, the resistance R5 are 10 k Ω.

6. the anti-reverse charging charging circuit of a kind of Intelligent bracelet according to claim 1, it is characterised in that the NMOS tube is ME1702。