CN202713563U

CN202713563U - Bluetooth earphone circuit board

Info

Publication number: CN202713563U
Application number: CN 201120548614
Authority: CN
Inventors: 刘晓颖; 薛林; 孙明艳; 杨会芹; 兰晓光
Original assignee: Goertek Inc
Priority date: 2011-12-23
Filing date: 2011-12-23
Publication date: 2013-01-30
Anticipated expiration: 2021-12-23

Abstract

The utility model provides a Bluetooth earphone circuit board. The Bluetooth earphone circuit board comprises a first signal layer S1, a grounding layer G, a power supply layer P and a second signal layer S2. The Bluetooth earphone circuit board is characterized in that radio frequency power supply of the circuit board is in the power supply layer or the second signal layer S2, and is physically isolated from other power supply circuits, and power is independently supplied through a power source outlet. With the Bluetooth earphone circuit board adopted, a radio frequency power source can be isolated from other power source portions, thereby effectively reducing the interference of an simulation interference source and the like quite on sensitive parts of the circuits.

Description

The Bluetooth earphone circuit plate

Technical field

The utility model relates to the bluetooth earphone technical field, more specifically, relates to a kind of Bluetooth earphone circuit plate that can improve radio-frequency sensitivity.

Background technology

Bluetooth is a kind of short-distance wireless communication technology of low cost low-power consumption.Popularizing along with blue tooth products and applications of wireless technology in recent years, bluetooth earphone become at present most widely used in daily life Bluetooth technology, by bluetooth earphone, the cellphone subscriber can realize wireless handsfree function, and needn't hang down from the head as it is single line to mobile phone.

The sound pressure level that earphone can send when the sensitivity of bluetooth earphone referred to and inputs the power of 1 milliwatt to earphone, its reflection be in the situation of same loudness, need the size of the power of input.The higher needed input power of earphone sensitivity is less, and the sound of exporting under the source of sound of same power is larger, and the higher needed input power of sensitivity is less, so sensitivity is very important index when selecting bluetooth earphone.

Fig. 1 is the schematic diagram of existing bluetooth earphone internal circuit board.As shown in Figure 1, existing Bluetooth earphone circuit plate is generally four-layer circuit board, and ground floor is signals layer S1, and the second layer is ground plane G, and the 3rd layer is bus plane P, and the 4th layer is signals layer S2.In order to improve the entire system service behaviour, make the impedance of element supply path as far as possible low, prevent system voltage, element voltage and interelement voltage is excessive falls, usually bus plane P is spread to be power supply.

But because Bluetooth earphone circuit plate itself is smaller, the power supply that can cause inevitably spreading can't absorb all interference, particularly radio-frequency power supply is easy to be subject to the impact of interference source on every side, and Ba Lun filter power supply ripple can increase, thereby causes the reduction of radio-frequency sensitivity.

The utility model content

Increase the problem that causes radio-frequency sensitivity to reduce in order to overcome bluetooth earphone internal circuit board mini-bus human relations filter Dian Yuan Pattern because of interference source impact on every side, the utility model provides a kind of novel board design, this design not only can effectively reduce power supply EMI, and can improve radio-frequency sensitivity.

The technical scheme that its technical problem that solves the utility model adopts is: in bus plane P, the power supply full wafer that spreads process, but for the filter power supply, then adopt directly from the power supply of master chip power output end, and separate interval 0.5-1mm with other electricity consumption.Reach Ba Lun filter power supply ripple minimum thereby make, and be not vulnerable to the impact of interference source on every side.

According to an aspect of the present utility model, a kind of Bluetooth earphone circuit plate is provided, comprise first signal layer S1, ground plane G, bus plane P and secondary signal layer S2, it is characterized in that, the radio frequency powered of described circuit board is powered from power outlet separately in bus plane P or secondary signal layer S2 and other power supply circuits physical isolation.

Wherein, preferred structure is, the radio frequency powered of described circuit board is spaced apart 0.5～1mm between bus plane P or secondary signal layer S2 and other power supply circuits.

In addition, preferred structure is to divide power zone block at described bus plane P according to the number of power sources of described Bluetooth earphone circuit plate.

Utilize above-mentioned according to Bluetooth earphone circuit plate of the present utility model, physical isolation radio-frequency power supply and other power unit in bus plane P, thereby effectively reduce to simulate interference source etc. to the interference of the relatively more responsive part of radio circuit, thereby from circuit layout (LAYOUT), improve radio-frequency performance, greatly reduce cost.

In order to realize above-mentioned and relevant purpose, one or more aspects of the present utility model comprise the feature that the back will describe in detail and particularly point out in the claims.Following explanation and accompanying drawing describe some illustrative aspects of the present utility model in detail.Yet, the indication of these aspects only be some modes that can use in the variety of way of principle of the present utility model.In addition, the utility model is intended to comprise all these aspects and their equivalent.

Description of drawings

By the content of reference below in conjunction with the description of the drawings and claims, and along with understanding more comprehensively of the present utility model, other purpose of the present utility model and result will understand and easy to understand more.In the accompanying drawings:

Fig. 1 is existing Bluetooth earphone circuit layer structure schematic diagram;

Fig. 2 is top layer bluetooth power outlet filter circuit plane graph, electricity consumption plane of inlet figure.

Fig. 3 is ground plane surfaces figure.

Fig. 4 is the bus plane plane graph.

Fig. 5 is ground floor plan;

Fig. 6 is equivalent electric circuit of the present utility model.

Identical label is indicated similar or corresponding feature or function in institute's drawings attached.

Embodiment

Below with reference to accompanying drawing specific embodiment of the utility model is described in detail.

The problem that increases in order to solve Ba Lun filter power supply ripple, in the Bluetooth earphone circuit that the utility model provides, human relations filter power supply is directly drawn from Bluetooth chip internal electric source output, can effectively reduce power supply EMI(Electromagnetic Interference like this, electromagnetic interference), thus improve the radio-frequency performance of bluetooth earphone.

The Bluetooth earphone circuit plate that the utility model provides also comprises totally four layers of first signal layer S1, ground plane G, bus plane P and secondary signal layer S2, respectively every one deck is described in detail below in conjunction with accompanying drawing.

Fig. 2 shows the filter circuit schematic diagram according to the top layer bluetooth power outlet of the utility model embodiment.

In the circuit of top layer shown in Figure 2 (being first signal layer S1), 1 for power supply output decoupling capacitance, links to each other with power output.2 are the electricity consumption power filtering capacitor, link to each other with the power supply input port, and the each several part of electricity consumption power filtering capacitor 2 all will obtain power supply by the power plane of bus plane P.3 is radio-frequency filter, links to each other with the power supply input port.

Fig. 3 is the floor map according to the ground plane of the utility model embodiment.Ground plane G can allow line signal reflux rapidly.

Fig. 4 and Fig. 5 are respectively according to the bus plane of the utility model embodiment and bottom floor map.In Fig. 4 and Fig. 5, radio frequency powered is powered from power outlet separately at bus plane P or secondary signal layer S2, that is to say, directly power to radio-frequency filter from the power output end of bluetooth earphone master chip, and will these independent power supply circuits separate with other circuit of bus plane, rather than be power supply as of the prior art whole bus plane is all spread.

Consider the size of circuit board and to the requirement of bluetooth earphone sensitivity, in a preferred implementation of the present utility model, physical separation between other circuit of the independent power supply circuits of filter and bus plane is designed to 0.5～1mm, fully reaching the isolation of radio-frequency power supply and other power unit, thereby effectively reduce to simulate interference source etc. to the interference of the relatively more responsive part of radio circuit.If in the system several power supplys are arranged, can be at many minutes several power zone blocks of bus plane P, such as just minute several power zone blocks of several power supplys are arranged, physical isolation between the block is to avoid as far as possible the electromagnetic interference between circuit.

Fig. 6 is the schematic equivalent circuit according to the utility model embodiment.

In Fig. 6, the equivalent electric circuit of the power plane from power output to bus plane P is formed circuit in parallel with equivalent inductance L1 after equivalent inductance L2 and capacitor C 1 series connection, because equivalent inductance L1, L2 be very little (generally below 1nH), so impedance can approximate C1.

The equivalent electric circuit of part from the power output to the radio frequency powered, for after 3 series connection of resistance R 1 and inductance L with capacitor C 2 formed circuit in parallel, the resistance of R1 is generally 0.25-0.55 Ω, so effectively also be L3, C2.

When the interference that has from circuit power plane (particularly VDD LO, VDD ANA), because power plane can equivalence be capacitor C 1, so absorbing a part, power plane disturbs., waited when arriving radio-frequency power supply through behind L3, the C2 by power output, disturb and reduced greatly.This measure of hiding interference is a kind of a kind of more effective, cheap measure of finding behind the interference source place.

As above describe according to Bluetooth earphone circuit plate of the present utility model in the mode of example with reference to accompanying drawing.But, those skilled in the art are to be understood that, for the Bluetooth earphone circuit plate that above-mentioned the utility model proposes, can also make various improvement on the basis that does not break away from the utility model content, such as increase and decrease or change components and parts on the first signal layer S1 etc.Therefore, protection range of the present utility model should be determined by the content of appending claims.

Claims

1. Bluetooth earphone circuit plate, comprise first signal layer (S 1), ground plane (G), bus plane (P) and secondary signal layer (S2), it is characterized in that, the radio frequency powered circuit of described circuit board is powered from power outlet separately at bus plane (P) or secondary signal layer (S2) and other power supply circuits physical isolation.

2. Bluetooth earphone circuit plate as claimed in claim 1 is characterized in that, the radio frequency powered of described circuit board is spaced apart 0.5～1mm between bus plane (P) or secondary signal layer (S2) and other power supply circuits.

3. Bluetooth earphone circuit plate as claimed in claim 1 is characterized in that, divides power zone block at described bus plane (P) according to the number of power sources of described Bluetooth earphone circuit plate.