CN201654589U

CN201654589U - Shunt regulating circuit

Info

Publication number: CN201654589U
Application number: CN2010201161474U
Authority: CN
Inventors: 陈俊; 梁隆军; 郑春桥
Original assignee: Zhejiang Nanrui Science and Technology Co Ltd
Current assignee: Zhejiang Nanrui Science and Technology Co Ltd
Priority date: 2010-02-02
Filing date: 2010-02-02
Publication date: 2010-11-24
Anticipated expiration: 2020-02-02

Abstract

The utility model relates to a shunt regulating circuit with high output power, low operating power consumption, simple structure and low cost, which comprises a voltage detection and control unit M1, a regulating transistor Q1 and an isolating diode D1. An input voltage terminal VIN is connected with an anode of the isolating diode D1 and a current input terminal of the regulating transistor Q1. A cathode of the isolating diode D1 is connected with a power input terminal of the voltage detection and control unit M1. A power output terminal of the voltage detection and control unit M1 is connected with an output voltage terminal VDD. A control output terminal of the voltage detection and control unit M1 is connected with a control terminal of the regulating transistor Q1. A current output terminal of the regulating transistor Q1 is connected with a system ground GND. When detecting that the voltage of the output voltage terminal VDD is higher or lower than a preset value, the voltage detection and control unit M1 correspondingly controls switch-on or switch-off of the regulating transistor Q1 so as to make the output voltage terminal VDD stable.

Description

A kind of shunt regulating circuit

Technical field

The utility model relates to a kind of shunt regulating circuit, is used for converting the current source of input to stable voltage output.

Background technology

At present, shunt regulating circuit is widely used in the mu balanced circuit design of current source output.More common shunt regulating circuit has two kinds: a kind of is as Fig. 1, adopting model is three-terminal voltage-stabilizing pipe and a little peripheral components formation of TL431, R5 is a current-limiting resistance among the figure, be serially connected with the adjustment end of input voltage VIN and TL431D1, output voltage V DD links to each other through the Voltage Reference pin Vout that resistance R 6, R7 dividing potential drop obtain reference voltage and TL431 (D2), and C3 is that filter capacitor is serially connected in output voltage terminal VDD and systematically between the GND.Because the power that device TL431 itself can bear is little, so this kind shunt regulating circuit real output is little, is not suitable in the bigger applications of output power.

Another kind is by comparer, adjust pipe and necessary resistance, devices such as stabilivolt constitute, as Fig. 2, Input voltage terminal VIN is through resistance R 8, stabilivolt D3 obtains reference voltage, and link to each other with the input end in the same way of comparer U2, the reverse input end of comparer U2 and resistance R 9, the dividing point of R10 links to each other, R81 links to each other with the grid of adjusting pipe Q2 behind the output terminal series resistor of comparer U2, the power pins of comparer U2 links to each other with comparer working power VCC, the drain electrode of adjusting pipe Q2 links to each other filter capacitor C4 with output voltage terminal VDD, C5 is serially connected in input voltage VIN and systematically between the GND.In above-mentioned shunt regulating circuit, resistance R 8 and stabilivolt D3 constitute the benchmark of adjusting voltage, resistance R 9, R10 constitute the feedback of adjusting voltage, comparer U2 is different by benchmark voltage and feedback voltage, the output corresponding control signal, control is adjusted the conducting of pipe Q2 or is ended, thereby reaches the purpose that makes output voltage terminal VDD voltage stabilizing.Therefore this circuit has the big advantage of output power owing to adopted the external independent pipe of adjusting.But also have following three shortcomings: (1), circuit input voltage VIN directly link to each other with output voltage V DD, and interference free performance and voltage output stability are poor in the practical application; (2), circuit feedback and control module use the comparer that does not have the hysteresis comparing function, the working point that causes adjusting pipe Q2 is in the amplification region of its output characteristics always, thereby causes adjusting pipe Q2 work temperature rise, power consumption is big.(3), want the circuit steady operation, the stable working power VCC that adds is provided must for comparer U2, so the circuit structure complexity, to use components and parts many and production cost is high.

The utility model content

The technical problems to be solved in the utility model provides that a kind of output power is big, operation is low in energy consumption, realize simple and the low shunt regulating circuit of production cost.

In order to solve the problems of the technologies described above, the utility model provides a kind of shunt regulating circuit, comprising: voltage detecting and control module M1, adjustment pipe Q1 and isolating diode D1; Input voltage terminal VIN connects the anode of described isolating diode D1 and adjusts the current input terminal of pipe Q1, the negative electrode of isolating diode D1 connects the power input with voltage detecting and control module M1, and the power output end of voltage detecting and control module M1 meets output voltage terminal VDD; The control output end of voltage detecting and control module M1 links to each other with the control end of adjusting pipe Q1; Adjust the current output terminal welding system ground GND of pipe Q1; When the voltage that detects current output voltage terminal VDD as voltage detecting and control module M1 was higher or lower than preset value, conducting or the closure of corresponding control adjustment pipe Q1 were so that output voltage terminal VDD is stable.

Further, described voltage detecting and control module M1 comprise the voltage comparator with hysteresis feature, and this voltage comparator and described isolating diode D1 compound action make and adjust saturation region or the cut-off region that pipe Q1 is operated in its output characteristics.

Further, described voltage comparator be have the hysteresis comparative characteristic special IC or by amplifier or comparer be core make up have a hysteretic characteristic voltage comparator circuit.

Further, described adjustment pipe Q1 is field effect transistor or bipolar transistor.

Further, described voltage detecting and control module M1 comprise: be located at output voltage terminal VDD and the bleeder circuit, voltage-level detector U1 pull-up resistor R1 and the pull down resistor R2 that are in series by the 3rd resistance R 3 and the 4th resistance R 4 between the GND systematically; The contact of the 3rd resistance R 3 and the 4th resistance R 4 links to each other with the input end Vin of voltage-level detector U1, the output end vo ut of voltage-level detector U1 meets the anode of described isolating diode D1 and GND systematically through pull-up resistor R1 and pull down resistor R2 respectively, the earth terminal G welding system ground GND of voltage-level detector U1, the output end vo ut of voltage-level detector U1 is the control output end of described voltage detecting and control module M1.

Further, output voltage terminal VDD and systematically be respectively equipped with filtering circuit between the GND.

Technique scheme of the present utility model has the following advantages compared to existing technology: (1), employing are adjusted pipe as external independent voltage trim, make circuit have the big advantage of output power; (2), adopt voltage comparator control to adjust the conducting of pipe or end with hysteresis feature, reduced and adjusted adjusting frequency of pipe, make and adjust saturation region or the cut-off region that pipe is operated in its output characteristics, adjust the shortcoming that the pipe working point is in the amplification region of its output characteristics always when having avoided using the common voltage comparer, significantly make and reduced the work temperature rise of adjusting pipe.(3), to adopt diode will adjust pipe and voltage detecting and control section isolated, reduced the interference of input to exporting, and improved the stability of output voltage and the reliability of circuit working.(4), to the utlity model has circuit structure simple, the applying electronic components and parts are few, the advantage that production cost is low.(5) pull-up resistor and pull down resistor are adjusted pipe for the back level appropriate bias voltage are provided, and prevent effectively that also the voltage-level detector output voltage is higher than the grid-control voltage of adjusting pipe simultaneously.

Description of drawings

For the easier quilt of content of the present utility model is clearly understood, below the specific embodiment and in conjunction with the accompanying drawings of basis, the utility model is described in further detail, wherein

Fig. 1 is the schematic diagram of shunt regulating circuit in the prior art;

Fig. 2 is the schematic diagram of another kind of shunt regulating circuit of the prior art;

Fig. 3 is the schematic diagram of shunt regulating circuit of the present utility model;

Fig. 4 among the embodiment pass through amplifier or comparer be core make up have a hysteretic characteristic voltage comparator circuit.

Embodiment

See Fig. 3, the shunt regulating circuit of present embodiment comprises: voltage detecting and control section M1, adjustment pipe Q1 and isolating diode D1.

Described voltage detecting and control section M1, output voltage V DD obtains feedback voltage after resistance R 3, R4 dividing potential drop, input has the input end Vin of the voltage comparator U1 of hysteresis feature, voltage-level detector U1 is by relatively voltage and the internal reference voltage (being described preset value) of this input end Vin, judge whether matching of current output voltage end VDD with the voltage value that designs, if the numerical value deviation exceeds the working range of voltage hysteresis band, then signal is adjusted in the output end vo ut of voltage-level detector U1 output accordingly.The output end vo ut of described voltage-level detector U1 moves output voltage V DD on resistance R 1, pull down to systematically GND through resistance R 2, resistance R 1 and resistance R 2 are adjusted pipe Q1 for the back level and have been carried for appropriate bias voltage, prevent effectively also simultaneously that voltage-level detector U1 output voltage is higher than the grid-control voltage of adjusting pipe Q1, damages and cause adjusting pipe Q1.

Described isolating diode D1 will adjust pipe Q1 and voltage detecting and control section M1 and be isolated into two parts, reduce the interference of input to output, improve the stability of output voltage.

The output end vo ut of described adjustment pipe Q1 grid and voltage-level detector U1 links to each other, its drain electrode links to each other with Input voltage terminal VIN, its source electrode links to each other with GND systematically, when signal is adjusted in voltage-level detector U1 output, adjust pipe Q1 by conducting or end, make corresponding reduction of voltage or the rising of Input voltage terminal VIN, thereby make the voltage of output voltage terminal VDD stable.

Voltage-level detector U1 among described voltage detecting and the control section M1 can be the special IC (is the special IC of NCP303 as model) with hysteresis comparative characteristic, and it has the simple advantage of circuit structure; Or by amplifier or comparer be core make up have a hysteretic characteristic voltage comparator circuit (see figure 4), wherein V1 is the comparator circuit input, V2 is comparator circuit output.

Described adjustment pipe Q1 can be field effect transistor or bipolar transistor, when using bipolar transistor, can save described pull-up resistor R1 and pull down resistor R2.

In order further to reduce output voltage Wen Bo, output voltage terminal VDD and systematically be respectively equipped with filtering circuit, i.e. capacitor C 1 and C2 between the GND.Also can increase T type or ∏ mode filter.

Obviously, the foregoing description only is for the utility model example clearly is described, and is not to be qualification to embodiment of the present utility model.For those of ordinary skill in the field, can also make other changes in different forms on the basis of the above description.Here need not also can't give exhaustive to all embodiments.And these belong to conspicuous variation or the change that spirit of the present utility model extended out and still are among the protection domain of the present utility model.

Claims

1. a shunt regulating circuit is characterized in that comprising: voltage detecting and control module (M1), adjustment pipe (Q1) and isolating diode (D1); Input voltage terminal (VIN) connects the anode of described isolating diode (D1) and adjusts the current input terminal of pipe (Q1), the negative electrode of isolating diode (D1) connects the power input with voltage detecting and control module (M1), and the power output end of voltage detecting and control module (M1) connects output voltage terminal (VDD); The control output end of voltage detecting and control module (M1) links to each other with the control end of adjusting pipe (Q1); Adjust the current output terminal welding system ground (GND) of pipe (Q1).

2. according to the described shunt regulating circuit of claim 1, it is characterized in that: described voltage detecting and control module (M1) comprise the voltage comparator with hysteresis feature.

3. according to the described shunt regulating circuit of claim 2, it is characterized in that: described voltage comparator be have the hysteresis comparative characteristic special IC or by amplifier or comparer be core make up have a hysteretic characteristic voltage comparator circuit.

4. according to the described shunt regulating circuit of one of claim 1-3, it is characterized in that: described adjustment pipe (Q1) is field effect transistor or bipolar transistor.

5. according to the described shunt regulating circuit of claim 1, it is characterized in that: described voltage detecting and control module (M1) comprising: be located at output voltage terminal (VDD) and the bleeder circuit, voltage-level detector (U1) pull-up resistor (R1) and the pull down resistor (R2) that are in series by the 3rd resistance (R3) and the 4th resistance (R4) between (GND) systematically;

The contact of the 3rd resistance (R3) and the 4th resistance (R4) links to each other with the input end (Vin) of voltage-level detector (U1), the output terminal (Vout) of voltage-level detector (U1) meets the anode of described isolating diode (D1) and systematically (GND) through pull-up resistor (R1) and pull down resistor (R2) respectively, earth terminal (G) the welding system ground (GND) of voltage-level detector (U1), the output terminal (Vout) of voltage-level detector (U1) is the control output end of described voltage detecting and control module (M1).

6. according to the described shunt regulating circuit of claim 5, it is characterized in that: described output voltage terminal (VDD) and systematically be respectively equipped with filtering circuit between (GND).