CN201585033U - Isolating driving circuit for remote sensing CCD camera - Google Patents

Abstract

The utility model relates to an isolating driving circuit for a remote sensing CCD camera, which comprises a voltage conversion circuit, an opto-coupler isolating circuit and a CMOS driving device circuit. The voltage conversion circuit carries out voltage conversion on an input power to establish a novel voltage reference system and supplies power to the opto-coupler isolating circuit after conversion. A time sequence pulse signal is first subjected to signal isolation by the opto-coupler isolating circuit to obtain a signal meeting the input requirement of a CMOS driving device, and then obtains a driving pulse signal of which a voltage and a power meet the working requirement of the CCD device by the CMOS driving device circuit. By increasing a power conversion circuit and the opto-coupler isolating circuit on the basis of the CMOS driving device circuit, on one hand, the isolating driving circuit for the remote sensing CCD camera makes the CMOS driving device which can only output a positive level driving signal capable of outputting positive and negative level driving signals, on the other hand, can make an output driving signal level of the CMOS driving device meet the requirement after the CMOS driving device with positive and negative level outputs is converted by the voltage reference system, thereby enlarging the using range of the CMOS driving device.

Description

Remote Sensing CCD Camera Isolation Drive Circuit

technical field

The utility model relates to an isolation driving circuit for a remote sensing CCD camera.

Background technique

The driving signal required for the operation of the CCD device, its high and low level values should meet specific requirements, and can provide sufficient power driving capability. At present, the general design method of CCD camera driving circuit is to directly select CMOS driving device for design, and the circuit only includes CMOS driving device circuit. The disadvantage of this circuit is that the voltage range of the output signal of CMOS driving device is limited. After a certain CMOS drive device is determined, the voltage range of its output signal is determined, and there are many types of drive signal voltages required for the CCD device to work. If each drive signal is only designed with a CMOS drive device circuit, it will cause all The types of CMOS drive devices required increase, and even CMOS drive devices that meet the requirements cannot be found.

Utility model content

The technical solution of the utility model is to overcome the deficiencies of the prior art and provide a remote sensing CCD camera isolation drive circuit which is widely applicable and can flexibly provide various drive signals.

The technical solution of the utility model is: a remote sensing CCD camera isolation drive circuit, including a voltage conversion circuit, an optocoupler isolation circuit, and a CMOS drive device circuit, wherein the voltage conversion circuit: utilizes a linear DC voltage regulator to perform voltage adjustment on an externally input DC power supply. Conversion, to provide the power required for the operation of the optocoupler device in the optocoupler isolation circuit; optocoupler isolation circuit: receive the timing pulse signal sent from the outside, use the optocoupler device to isolate the signal, and provide it to the CMOS drive device circuit; CMOS drive device Circuit: Receive the pulse signal after signal isolation sent by the optocoupler isolation circuit, perform voltage conversion and power drive through the CMOS drive device, obtain the drive signal and provide it to the CCD device.

The voltage conversion circuit includes a capacitor C1, a capacitor C2 and a linear DC voltage regulator; one end of the capacitor C1 is connected to the positive end of the external input power supply, and the other end of the capacitor C1 is connected to the negative end of the external input power supply; one end of the capacitor C2 It is connected to the output end of the linear DC voltage stabilizing device, and the other end of the capacitor C2 is connected to the negative end of the external input power supply; the input end of the linear DC voltage stabilizing device is connected to the positive end of the external input power supply, and the output end of the linear DC voltage stabilizing device As the output terminal of the voltage conversion circuit, the ground terminal of the linear DC regulator is connected to the negative terminal of the external input power supply.

Described optocoupler isolation circuit comprises resistance R1, resistance R2, resistance R3, electric capacity C3 and optocoupler device; The TTL/CMOS signal input positive terminal of external input is connected with the anode of light-emitting diode in the optocoupler device through resistance R1; The negative terminal of the TTL/CMOS signal input is connected to the cathode of the light-emitting diode; the ground terminal of the optocoupler is connected to the negative terminal of the external input power supply; the output terminal of the optocoupler is connected to one end of the resistor R3, and the other end of the resistor R3 is used as The output terminal of the optocoupler isolation circuit; the power supply terminal of the optocoupler device is connected to the output terminal of the voltage conversion circuit, the two ends of the resistor R2 are respectively connected to the power supply terminal and the output terminal of the optocoupler device, and the two ends of the resistor C3 are connected to the optocoupler device respectively. The power supply terminal of the device is connected to the ground terminal.

Described CMOS driving device circuit uses the circuit connection mode that does not possess high and low level control driving device to be: comprise resistance R4, resistance R5 and CMOS driving device; The signal input terminal is connected; the signal output terminal of the COMS driving device is connected to one end of the resistor R5, and the other end of the resistor R5 is used as the output terminal of the CMOS driving circuit; the positive terminal of the power supply of the COMS driving device is connected to the positive terminal of the external input power supply; the COMS driving device The ground end of the ground is connected to the negative end of the external input power supply.

Described CMOS driving device circuit uses the circuit connection mode that possesses high and low level control driving device to be: comprise resistance R6, resistance R7 and CMOS driving device; The input terminal is connected; the signal output terminal of the COMS drive device is connected to one end of the resistor R7, and the other end of the resistor R7 is used as the output terminal of the CMOS drive circuit; the power supply terminal, the work enable terminal, and the output high-level voltage terminal of the COMS drive device VH is connected to the positive terminal of the external input power supply at the same time; the ground terminal of the COMS drive device, the output low-level voltage terminal VL, and the negative terminal of the power supply are connected to the negative terminal of the external input power supply at the same time.

The capacitor C1, or the capacitor C2, or the capacitor C3 can be replaced by a filter network composed of capacitors, resistors, and inductors.

Compared with the prior art, the utility model has the advantages that: the utility model establishes a new voltage reference system by adding a power conversion circuit and an optocoupler isolation circuit on the basis of the traditional CMOS drive device circuit. On the one hand, it can only output positive The CMOS drive device with level drive signal can output positive and negative level drive signals. On the other hand, the CMOS drive device with positive and negative level output can also be converted through the voltage reference system so that the output drive signal level can meet the requirements and expand The scope of use of CMOS drive devices is widened, and the design of CCD camera drive signals is more flexible and versatile.

Description of drawings

Fig. 1 is a schematic circuit diagram of the utility model;

Fig. 2 is the schematic diagram of the voltage conversion circuit in the utility model;

Fig. 3 is the schematic diagram of the optocoupler isolation circuit in the utility model;

Fig. 4 is the schematic diagram of the first kind of CMOS driving device circuit in the utility model;

FIG. 5 is a schematic diagram of the second CMOS driving device circuit in the present invention.

Detailed ways

As shown in Figure 1, it is a block diagram of the composition principle of the utility model. The working process is as follows: first, the external input power passes through the voltage conversion circuit to establish a new voltage reference system, and the power obtained by the voltage conversion supplies power to the optocoupler isolation circuit. The TTL/CMOS timing pulse signal is isolated by the optocoupler to obtain the signal that meets the input requirements of the CMOS drive device, and then the drive pulse signal whose voltage and power meet the working requirements of the CCD device is obtained through the CMOS drive device circuit.

A specific circuit connection mode of the voltage conversion circuit is shown in FIG. 2 : the voltage conversion circuit is composed of a capacitor C1 , a capacitor C2 and a linear DC voltage stabilizing device 401 . One end of the capacitor C1 is connected to the input terminal 101 of the power supply V+, and the other end is connected to the input terminal 102 of the power supply V−. One end of the capacitor C2 is connected to the output terminal VOUT of the linear DC voltage stabilizing device 401, the output terminal VOUT of the linear DC voltage stabilizing device 401 is the output terminal 103 of the voltage conversion circuit, the other end of the capacitor C2 is connected to the power supply V- input terminal 102 and The ground terminal GND of the linear DC voltage stabilizing device 401 is connected. The input terminal VIN of the linear DC voltage stabilizing device 401 is connected to the input terminal 101 of the power supply V+. The main function of capacitor C1 and capacitor C2 is to filter and denoise the power supply. The linear DC voltage regulator device 401 is μA78M05 produced by Texas Instruments.

A specific circuit connection mode of the optocoupler isolation circuit is shown in FIG. 3 : the optocoupler isolation circuit is composed of resistors R1 , R2 , R3 , capacitor C3 , and optocoupler device 402 . The input TTL/CMOS signal IN is connected to the anode of the light-emitting diode of the optocoupler device 402 through the input terminal 104 through the resistor R1 , and the input signal return line 105 is connected to the cathode of the light-emitting diode of the optocoupler device 402 . The ground terminal GND of the optocoupler device 402 is connected to the power supply V-input terminal 102; the power supply terminal VCC of the optocoupler device 402 is connected to the output terminal 103 of the voltage conversion circuit, and connected to the power supply V-input terminal 102 through the capacitor C3. The output terminal OUT of the optocoupler device 402 is connected to one end of the resistor R3, the other end of the resistor R3 is used as the output terminal 106 of the optocoupler isolation circuit, and the two ends of the resistor R2 are respectively connected to the power supply terminal VCC and the output terminal OUT of the optocoupler device 402 . The main function of the resistor R1 is to limit the current, so that the current flowing through the light-emitting diode of the optocoupler device 402 is controlled within the required range. The resistor R2 is used as a pull-up resistor, and its main function is to pull the output terminal OUT of the optocoupler device 402 to a fixed level through the resistor R2 when the output is at a high level. The main function of the resistor R3 is to perform impedance matching to facilitate the signal integrity of the circuit PCB design. The function of capacitor C3 is to filter and denoise the power supply. The optocoupler device 402 is HCPL-0661 produced by Hewlett Packard Company.

The CMOS drive circuit can be a drive device without high and low level control, or a drive device with high and low level control.

The CMOS driving circuit uses a specific circuit connection method without high and low level control driving devices as shown in FIG. 4 : it is composed of resistors R4, R5, and a CMOS driving device 403. The signal isolated by the optocoupler device 402 is connected to the signal input terminal IN of the COMS drive device 403 through the output terminal 106 of the optocoupler isolation circuit through the resistor R4, and the signal output terminal OUT of the COMS drive device 403 is connected to one end of the resistor R5, and the resistor The other end of R5 serves as the output end 108 of the CMOS drive circuit, that is, SIG_out1 in the figure. The positive terminal of the power supply of the COMS driving device 403 is connected to the input terminal 101 of the power supply V+, and the ground terminal GND of the COMS driving device 403 is connected to the input terminal 102 of the power supply V−. The main function of resistor R4 is to perform current limiting protection. The main function of resistor R5 is to perform impedance matching. The CMOS driving device 403 is EL7212 from Elantec Company.

The CMOS driving circuit uses a specific circuit connection method with high and low level control driving devices as shown in FIG. 5 : it consists of resistors R6, R7, and a CMOS driving device 404. The signal isolated by the optocoupler device 402 is connected to the signal input terminal IN of the COMS drive device 404 through the output terminal 106 of the optocoupler isolation circuit through the resistor R6, and the signal output terminal OUT of the COMS drive device 404 is connected to one end of the resistor R7. The other end of R7 is used as the output end 109 of the CMOS driving circuit, that is, SIG_out2 in the figure. The positive power supply VS+, work enable OE, and output high-level voltage VH of the COMS drive device 404 are connected to the power supply V+ input terminal 101 at the same time, and the ground GND, output low-level voltage VL, and negative power supply VS- of the COMS drive device 404 are connected to the power supply The V-input 102 is connected. The main function of resistor R6 is to perform current limiting protection. The main function of resistor R7 is to perform impedance matching. The CMOS driving device 404 is EL7457 from Elantec Company.

The content that is not described in detail in the description of the utility model belongs to the known technology of those skilled in the art.

Claims (6)

1. the remote sensing CCD camera isolated drive circuit is characterized in that comprising voltage conversion circuit, optical coupling isolation circuit, cmos driver spare circuit, wherein:

Voltage conversion circuit: utilize the linear DC voltage-stabilizing device that the DC power supply of outside input is carried out voltage transitions, the required power supply of optocoupler work in the optical coupling isolation circuit is provided;

Optical coupling isolation circuit: receive the outside time sequential pulse signal of sending into, utilize optocoupler to carry out Signal Spacing after, offer cmos driver spare circuit;

Cmos driver spare circuit: receive the pulse signal after Signal Spacing that optical coupling isolation circuit is sent into, carry out voltage transitions and power drive, obtain drive signal and offer the CCD device by cmos driver spare.

2. remote sensing CCD camera isolated drive circuit according to claim 1 is characterized in that: described voltage conversion circuit comprises capacitor C 1, capacitor C 2 and linear DC voltage-stabilizing device (401); One end of capacitor C 1 links to each other with the anode (101) of outside input power supply, and the other end of capacitor C 1 links to each other with the negative terminal (102) of outside input power supply; One end of capacitor C 2 links to each other with the output of linear DC voltage-stabilizing device (401), and the other end of capacitor C 2 links to each other with the negative terminal (102) of outside input power supply; The input of linear DC voltage-stabilizing device (401) links to each other with the anode (101) of outside input power supply, the output of linear DC voltage-stabilizing device (401) is as the output (103) of voltage conversion circuit, and the earth terminal of linear DC voltage-stabilizing device (401) links to each other with the negative terminal (102) of outside input power supply.

3. remote sensing CCD camera isolated drive circuit according to claim 2 is characterized in that: described optical coupling isolation circuit comprises resistance R 1, resistance R 2, resistance R 3, capacitor C 3 and optocoupler (402); The TTL/CMOS signal input anode (104) of outside input links to each other with the anode of light-emitting diode in the optocoupler (402) by resistance R 1; The TTL/CMOS signal input negative terminal (105) of outside input links to each other with the negative electrode of described light-emitting diode; The earth terminal of optocoupler (402) links to each other with the negative terminal (102) of outside input power supply; The output of optocoupler (402) is connected to an end of resistance R 3, and the other end of resistance R 3 is as the output (106) of optical coupling isolation circuit; The power end of optocoupler (402) is connected to the output (103) of voltage conversion circuit, the two ends of resistance R 2 link to each other with output with the power end of optocoupler (402) respectively, and the two ends of resistance C3 link to each other with earth terminal with the power end of optocoupler (402) respectively.

4. remote sensing CCD camera isolated drive circuit according to claim 3 is characterized in that: described cmos driver spare circuit uses the circuit connecting mode that does not possess high and low level controlling and driving device to be: comprise resistance R 4, resistance R 5 and cmos driver spare (403); The output of optical coupling isolation circuit (106) links to each other with the signal input part of COMS driving element (403) by resistance R 4; The signal output part of COMS driving element (403) is connected to an end of resistance R 5, and the other end of resistance R 5 is as the output (108) of CMOS drive circuit; The power positive end of COMS driving element (403) connects the anode (101) of outside input power supply; The earth terminal of COMS driving element (403) links to each other with the negative terminal (102) of outside input power supply.

5. remote sensing CCD camera isolated drive circuit according to claim 3 is characterized in that: described cmos driver spare circuit uses the circuit connecting mode that possesses high and low level controlling and driving device to be: comprise resistance R 6, resistance R 7 and cmos driver spare (404); The output of optical coupling isolation circuit (106) links to each other with the signal input part of COMS driving element (404) by resistance R 6; The signal output part of COMS driving element (404) is connected to an end of resistance R 7, and the other end of resistance R 7 is as the output (109) of CMOS drive circuit; The power positive end of COMS driving element (404), work Enable Pin, output high level voltage end VH link to each other with the anode (101) of outside input power supply simultaneously; The earth terminal of COMS driving element (404), output low level voltage end VL, power supply negative terminal link to each other with the negative terminal (102) of outside input power supply simultaneously.

6. according to claim 4 or 5 described remote sensing CCD camera isolated drive circuits, it is characterized in that: described capacitor C 1, perhaps capacitor C 2, and perhaps capacitor C 3 is replaceable is the filter network of being made up of electric capacity, resistance, inductance.

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