CN205594145U

CN205594145U - USB input power type detection circuitry

Info

Publication number: CN205594145U
Application number: CN201620289932.7U
Authority: CN
Inventors: 张子林
Original assignee: Xiamen Intretech Inc
Current assignee: Xiamen Intretech Inc
Priority date: 2016-04-08
Filing date: 2016-04-08
Publication date: 2016-09-21
Anticipated expiration: 2026-04-08

Abstract

The utility model discloses a USB input power type detection circuitry, include: controller and measuring circuit, the measuring circuit includes firstly to the 3rd NPN triode and first to the 5th divider resistance, and whether the work of controller control survey circuit, receives the output quantity of measuring circuit simultaneously, and then judge USB input power type, and the measuring junction of measuring circuit is connected with the signal line of USB interface, imports the power type to the USB of difference, and the output quantity of exporting different level is for the controller. The utility model discloses only need that circuit that ordinary NPN triode and resistance built is just can be high -efficient quick to be detected USB input power type, detect fast, simple structure, the circuit is small, does benefit to the device miniaturization, the cost has been saved effectively to the while.

Description

USB input power type detecting circuit

Technical field

This utility model belongs to electronic circuit field, more particularly to a kind of USB input power type detecting circuit.

Background technology

USB (Universal Serial Bus, USB (universal serial bus)) is a kind of to apply the interfacing in computer realm, has been widely used at present in each electronic product such as mobile phone, portable player, computer peripheral equipment.Owing to USB standard can provide the voltage of 5V, the electrical equipment the most much using battery system to power, USB can be used to be charged.

Use USB charging can be inserted on special power supply adaptor being charged, Universal USB 2.0 interface that can also be inserted into apparatus such as computer is charged, when using apparatus such as computer to be charged, needing to limit its maximum charging current is 500mA, and charging current is less, and charging rate is slower, during if charging adapter is charged, then can be charged according to the charging current of product actual demand, charging current is relatively big, and charging rate is fast.And charging current different time, the management mode of charge management circuit also can be different, therefore, during charging, need to know USB input power type, in order to be charged management.This needs exist for a kind of circuit that can detect USB input power type, and more existing testing circuit components and parts are many, and structure is complicated, and circuit volume is big, and cost is high, and detection speed is slower.

Summary of the invention

This utility model purpose is to provide a kind of detection speed fast for solving the problems referred to above, and circuit components is few, simple in construction, and circuit volume is little, the USB input power type detecting circuit of low cost.

nullFor this，The utility model discloses a kind of USB input power type detecting circuit，Including: controller and measuring circuit，Described measuring circuit includes the first to the 3rd NPN audion and the first to the 5th divider resistance，The control output end of described controller is sequentially connected in series the first to the 3rd divider resistance and connects the base stage of the 3rd NPN audion，Series connection the 4th divider resistance connects the detection input of controller simultaneously，The colelctor electrode of a described NPN audion connects the base stage of the 3rd NPN audion，Its base stage is connected on the node of the first divider resistance and the second divider resistance，Its emitter stage connects a wherein signal line of USB interface，The colelctor electrode of described 2nd NPN audion connects the detection input of controller，Its emitter stage is sequentially connected in series the 5th divider resistance and the 3rd NPN audion ground connection，Connect another signal line of USB interface simultaneously，Its base stage is connected on second and the 3rd between divider resistance，The difference of the described second and the 3rd dividing potential drop between divider resistance and the 3rd NPN audion cut-in voltage is not more than the cut-in voltage of the 2nd NPN audion.

Further, described controller is MCU processor.

Further, the resistance of described first to the 5th divider resistance is respectively 10k, 10k, 10k, 100k, 10k.

Advantageous Effects of the present utility model:

This utility model only needs common NPN audion and resistance to carry out building circuit, it is possible to quickly detecting that the power supply type that USB inputs is apparatus such as computer or charging adapter, circuit components is few, simple in construction, circuit volume is little, beneficially device miniaturization, low cost.

Accompanying drawing explanation

Fig. 1 show the functional-block diagram of this utility model embodiment；

Fig. 2 show the circuit theory diagrams of this utility model embodiment.

Detailed description of the invention

In conjunction with the drawings and specific embodiments, the present invention is further described.

As shown in Figure 1 and Figure 2, a kind of USB input power type detecting circuit, including: controller 1 and measuring circuit 2, described measuring circuit 2 includes first to the 3rd NPN audion Q1, Q2, Q3 and first to the 5th divider resistance R1, R2, R3, R4, R5, in this specific embodiment, controller 1 is MCU microprocessor, certainly, in other embodiments, controller 1 can also be single-chip microcomputer, arm processor etc..

nullThe control output end USB_V of described MCU microprocessor 1 is sequentially connected in series divider resistance R1、R2 and R3 connects the base stage (control end) of NPN audion Q3，Series connection divider resistance R4 meets the detection input USB_DET of MCU microprocessor 1 simultaneously，The colelctor electrode (input) of NPN audion Q1 connects the base stage of NPN audion Q3，Base stage (control end) is connected on the node between divider resistance R1 and divider resistance R2，Emitter stage (outfan) connects wherein signal line D+ of USB interface J1，Certainly，In other embodiments，Other signal line D-can also be connect，The colelctor electrode (input) of described NPN audion Q2 meets the detection input USB_DET of MCU microprocessor，Emitter stage (outfan) is sequentially connected in series divider resistance R5 and NPN audion Q3 ground connection，Connect another signal line D-of USB interface J1 simultaneously，Certainly，In other embodiments，Can also be holding wire D+，Base stage (control end) is connected on the node between divider resistance R2 and R3，Wherein，The difference of the dividing potential drop between divider resistance R2 and R3 and NPN audion Q3 base voltage (cut-in voltage) must be not more than the cut-in voltage of NPN audion Q2.

Concrete, in the present embodiment, divider resistance R1, R2, R3, R4, R5 are respectively 10k, 10k, 10k, 100k, 10k.

The work process of this utility model embodiment:

The control output end USB_V of MCU microprocessor 1 exports high level, detection starts, when USB interface J1 input power is power supply adaptor when, holding wire D+ and D-of USB interface J1 is short circuit, and now, NPN audion Q1 and Q3 turns on, the emitter stage current potential of NPN audion Q2 is driven high, end less than its cut-in voltage, NPN audion Q2 with the voltage difference of its base stage, then the detection input USB_DET of MCU microprocessor 1 is high level；When Universal USB 2.0 interface that USB interface J1 input power is apparatus such as computer, holding wire D+ and D-of USB interface J1 is off, now NPN audion Q1, Q2 and Q3 turn on, the voltage of the detection input USB_DET of MCU microprocessor 1 is then the dividing potential drop of divider resistance R5, it it is then low level, therefore, by judging that the detection input USB_DET of MCU microprocessor 1 is high level or low level i.e. may know that USB interface input power is power supply adaptor or the Universal USB of apparatus such as computer 2.0 interface, it is achieved the detection of USB interface input power type.The control output end USB_V output low level of MCU microprocessor 1, detection terminates.

Although specifically showing in conjunction with preferred embodiment and describing this utility model; but those skilled in the art should be understood that; in the spirit and scope of the present utility model limited without departing from appended claims; this utility model can be made a variety of changes in the form and details, be protection domain of the present utility model.

Claims

null1.USB input power type detecting circuit，It is characterized in that，Including: controller and measuring circuit，Described measuring circuit includes the first to the 3rd NPN audion and the first to the 5th divider resistance，The control output end of described controller is sequentially connected in series the first to the 3rd divider resistance and connects the base stage of the 3rd NPN audion，Series connection the 4th divider resistance connects the detection input of controller simultaneously，The colelctor electrode of a described NPN audion connects the base stage of the 3rd NPN audion，Its base stage is connected on the node of the first divider resistance and the second divider resistance，Its emitter stage connects a wherein signal line of USB interface，The colelctor electrode of described 2nd NPN audion connects the detection input of controller，Its emitter stage is sequentially connected in series the 5th divider resistance and the 3rd NPN audion ground connection，Connect another signal line of USB interface simultaneously，Its base stage is connected on second and the 3rd between divider resistance，The difference of the described second and the 3rd dividing potential drop between divider resistance and the 3rd NPN audion cut-in voltage is not more than the cut-in voltage of the 2nd NPN audion.
USB input power type detecting circuit the most according to claim 1, it is characterised in that: described controller is MCU microprocessor.
USB input power type detecting circuit the most according to claim 1 and 2, it is characterised in that: the resistance of described first to the 5th divider resistance is respectively 10k, 10k, 10k, 100k, 10k.