CN201355808Y

CN201355808Y - High bandwidth linear isolation module

Info

Publication number: CN201355808Y
Application number: CNU2009200884793U
Authority: CN
Inventors: 张兴杰
Original assignee: Individual
Current assignee: Individual
Priority date: 2009-02-11
Filing date: 2009-02-11
Publication date: 2009-12-02
Anticipated expiration: 2019-02-11

Abstract

The utility model discloses a high bandwidth linear isolation module comprising a linear optical coupler, a wideband transformer, an operational amplifier and two summing circuits; wherein a non inverting input end of the operational amplifier is a signal input end, and an output end thereof is electrically connected with optical-electrical conversion ends of the linear optical coupler by a resistor; optical-electrical conversion ends of the linear optical coupler are respectively electrically connected with a power supply by resistors; primary coils of the wideband transformer are electrically connected with the output end of the operational amplifier after being serially connected with a resistor by a capacitor; two secondary coils are respectively electrically connected with input ends of the two summing circuits; the other input ends of the two summing circuits are respectively electrically connected with two optical-electrical conversion ends of the linear optical coupler; the output end of one summing circuit is electrically connected with an inverse input end of the operational amplifier by a resistor; and the output end of the other summing circuit is a signal output end. The high bandwidth linear isolation module has the advantage of adopting small-volume and low-cost micro elements to realize high bandwidth linear electric isolation of analog signals with gain G equaling 1.

Description

The linear isolation module of high bandwidth

Technical field

The utility model relates to the analog signal isolation module, especially relates to the linear isolation module of high bandwidth.

Background technology

Based on safety, anti-interference consideration, the transmission of analog signal all relates to the electrical isolation problem in many systems, oscilloscope for example, observe the primary and secondary signal of an isolating transformer simultaneously with oscillographic two passages when needs, if oscillographic two passages are not taked the electrical isolation measure, certainly will cause between the isolating transformer primary and secondary to produce to be electrically connected and to cause beyond thought serious consequence.At present, aspect the analog signal isolation, low frequency is linear isolates and manyly is made up of isolated amplifier or linear optocoupler and operational amplifier and peripheral circuit, but its operating frequency is generally below 1MHz; The high frequency linearity isolation takes wide-band transformer and operational amplifier and peripheral circuit to realize more, and its operating frequency is generally more than tens KHz; But the linear spacer assembly or the module that are adapted to the above bandwidth of 0-100MHz are at present also rare.

The utility model content

The utility model purpose is to provide the high bandwidth that a kind of volume is little, cost is low linear isolation module.

For achieving the above object, the utility model can be taked following technical proposals:

The linear isolation module of high bandwidth described in the utility model, it comprises linear optocoupler, wide-band transformer, operational amplifier and two summing circuits; The in-phase input end of described operational amplifier is a signal input part, and its output is electrically connected with the electric light end of convert of described linear optocoupler by resistance; The opto-electronic conversion end of described linear optocoupler is electrically connected with separately power supply by resistance respectively, the primary coil of described wide-band transformer is electrically connected with operational amplifier output terminal by electric capacity and resistance series connection back, and two secondary coil is electrically connected with the input of described two summing circuits respectively; Another input of two summing circuits is electrically connected with two opto-electronic conversion ends of linear optocoupler respectively; A summing circuit output is electrically connected with the inverting input of operational amplifier by resistance; The output of another summing circuit is a signal output part.

The ratio of the number of turn of the primary and secondary coil of described wide-band transformer is 1: 1: 1; The resistance of described resistance equates; Described power supply amplitude equates.

The utility model advantage is to adopt volume is little, price is low micro element to realize the linear electrical isolation of high bandwidth of the analog signal of gain G=1.Can be circuit package that one overall structure is used as an isolated amplifier when making simultaneously.

Description of drawings

Fig. 1 is circuit theory diagrams of the present utility model.

Embodiment

As shown in the figure, the linear isolation module of high bandwidth described in the utility model, it comprises linear optocoupler U, wide-band transformer T, operational amplifier A 1 and two summing circuit A2, A3; The in-phase input end of described operational amplifier A 1 is the signal input part of this module, and its output is electrically connected with the electric light end of convert D1 of described linear optocoupler U by resistance R 4; Opto-electronic conversion end D2, the D3 of described linear optocoupler U is electrically connected with separately power supply VCC1, VCC2 by resistance R 1, R2 respectively, the primary coil N1 of described wide-band transformer T is electrically connected with operational amplifier A 1 output by capacitor C and resistance R 3 series connection backs, two secondary coil N2, N3 are electrically connected with input V1, the V3 of described two summing circuit A2, A3 respectively, and the ratio of the primary and secondary coil N1 of wide-band transformer T, the number of turn of N2, N3 is 1: 1: 1; Another input V2, the V4 of two summing circuit A2, A3 is electrically connected with two opto-electronic conversion ends of linear optocoupler U respectively; Summing circuit A2 output V ₀1 passes through resistance R 6 is electrically connected with the inverting input of operational amplifier A 1; The output V of summing circuit A3 ₀2 is the signal output part of this module.

Circuit working principle of the present utility model is as follows:

The signal of this circuit has two passages, a low channel and a hf channel, and signal medium-high frequency composition arrives the V1 input of summing circuit A2 and the V3 input of summing circuit A3 by wide-band transformer T;

Equally, the low-frequency component in the signal arrives the V2 input of summing circuit A2 and the V4 input of summing circuit A3 by linear optocoupler U; The signal of V1 input and V2 input outputs to its output end vo 1 after summing circuit A2 summation; The signal of V3 input and V4 input outputs to its output end vo 2 after summing circuit A3 summation; Because there is the zone of overlapping in the operating frequency of linear optocoupler U and wide-band transformer T, so the signal of whole bandwidth can arrive output end vo 1, the Vo2 point of two summing circuit A2, A3; Because the error of component parameters always exists in the circuit, so compare to the inverting input of operational amplifier A 1 and the input signal Vi of in-phase input end the signal feedback of 1 of the output end vo of summing circuit A2, operational amplifier A 1 is adjusted its output amplitude according to output end vo 1 voltage of summing circuit A2 and the voltage deviation of input signal Vi, finally makes the voltage (with respect to the reference GND1 before isolating) of the output voltage V o1=input signal Vi of summing circuit A2; Because VCC1=VCC2, R1=R2, therefore the voltage of summing circuit A3 output end vo 2 (with respect to the reference GND2 after isolating) equals the voltage (with respect to the reference GND1 before isolating) of summing circuit A2 output end vo 1, thereby realizes the linear electrical isolation of high bandwidth of the analog signal of gain G=1.

Claims

1, the linear isolation module of a kind of high bandwidth, it comprises linear optocoupler (U), wide-band transformer (T), operational amplifier (A1) and two summing circuits (A2, A3); It is characterized in that: the in-phase input end of described operational amplifier (A1) is a signal input part, and its output is electrically connected with the electric light end of convert (D1) of described linear optocoupler (U) by resistance (R4); The opto-electronic conversion end of described linear optocoupler (U) (D2, D3) is electrically connected with separately power supply (VCC1, VCC2) by resistance (R1, R2) respectively, the primary coil (N1) of described wide-band transformer (T) is electrically connected with operational amplifier (A1) output by electric capacity (C) and resistance (R3) series connection back, and two secondary coil (N2, N3) is electrically connected with the input (V1, V3) of described two summing circuits (A2, A3) respectively; Another input (V2, V4) of two summing circuits (A2, A3) is electrically connected with two opto-electronic conversion ends of linear optocoupler (U) respectively; Summing circuit (A2) output (V ₀1) is electrically connected with the inverting input of operational amplifier (A1) by resistance (R6); Output (the V of summing circuit (A3) ₀2) be signal output part.

2, the linear isolation module of high bandwidth according to claim 1, it is characterized in that: the ratio of the number of turn of the primary and secondary coil of described wide-band transformer (T) (N1, N2, N3) is 1: 1: 1; The resistance of described resistance (R1, R2) equates; Described power supply (VCC1, VCC2) amplitude equates.