An IR CUT driving circuit
The IR CUT driver circuit built with an audio PA chip uses a single GPIO interface to control the switching of IR CUT filters, which solves the problem of excessive GPIO usage in multi-view cameras and realizes a highly integrated and low-power IR CUT driver circuit design.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- BEIJING TSINGMICRO INTELLIGENT TECH CO LTD
- Filing Date
- 2025-05-08
- Publication Date
- 2026-05-29
AI Technical Summary
In multi-view cameras, the IR CUT function unit consumes a large number of CPU GPIOs, causing product design problems.
An IR CUT driver circuit is built using an audio PA chip. The switching of the IR CUT filter is controlled through a single GPIO interface. The circuit includes a GPIO interface, a shaping circuit, and a power amplifier circuit to amplify positive and negative pulse signals.
It saves a lot of GPIO, improves integration, reduces board area and power consumption, and lowers circuit cost.
Smart Images
Figure CN224305750U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of integrated circuit technology, and in particular to an IR CUT driving circuit. Background Technology
[0002] In applications such as security cameras, including binocular and tri-lens PTZ cameras, there are many peripherals, requiring the CPU to have enough GPIOs for logic control. In practice, there is often a situation where the number of CPU GPIOs is insufficient.
[0003] An IR CUT is one of the peripheral devices for cameras. By switching the IR CUT filter, the light requirements of the camera imaging under different lighting scenarios can be met.
[0004] Typically, each sensor requires a corresponding IR CUT functional unit. Each IR CUT requires two GPIOs to control the switching of the IR CUT filter. In multi-view scenarios, the IR CUT functional unit will occupy a large number of CPU GPIOs, causing trouble for product design. Utility Model Content
[0005] To address the technical problems existing in the background art described above, this disclosure provides an IR CUT driving circuit.
[0006] According to one aspect of this application, an IR cut driver circuit is provided, comprising: a GPIO interface, a shaping circuit, and a power amplifier circuit, wherein...
[0007] The GPIO interface is used to connect to the corresponding GPIO interface of the processor and receive GPIO signals issued by the processor;
[0008] The shaping circuit is used to shape the rising and falling edges of GPIO signals into positive and negative pulse signals;
[0009] The power amplifier circuit is used to amplify positive and negative pulse signals to a level that can drive the IR CUT filter. The power amplifier circuit is built based on an audio PA chip.
[0010] Optionally, the IR CUT driving circuit further includes: a connector for connecting the IR CUT filter of the peripheral device, used to send the received amplified positive and negative pulse signals to the IR CUT filter.
[0011] Optionally, positive and negative pulse signals are used to switch the IR CUT filter back and forth. Specifically, when the GPIO signal is in a high or low level state, the IR CUT driving circuit does not operate and the IR CUT filter is in a stopped state. When the GPIO signal is in a rising or falling edge state, it controls the IR CUT filter to switch back and forth.
[0012] Optionally, the shaping circuit includes a first resistor, a first capacitor, and a second capacitor, wherein...
[0013] One end of the first resistor is connected to the GPIO interface, and the other end is connected to the first capacitor and the second capacitor respectively. The first capacitor is grounded, and the second capacitor is connected to the power amplifier circuit.
[0014] Optionally, the power amplifier circuit consists of a second resistor, a third resistor, and an audio PA chip. The resistance values of the second and third resistors are used to adjust the amplification gain.
[0015] One end of the second resistor is connected to the second capacitor, and the other end is connected to the PIN4 pin of the audio PA chip; the two ends of the third resistor are connected to the PIN4 and PIN5 pins of the audio PA chip, respectively.
[0016] Optionally, pin 5 of the audio PA chip is used to output amplified negative pulse signals, and pin 8 is used to output amplified positive pulse signals.
[0017] Therefore, this utility model uses an audio PA chip to build an IR CUT driving circuit, realizing the control of IR CUT filter switching by a single GPIO interface, which can save a lot of GPIO, bringing great convenience to the design of multi-view cameras. The driving circuit has high integration, occupies a small circuit board area, and has low power consumption. The circuit cost is relatively lower than that of traditional dual GPIO control driving circuits.
[0018] The above and other objects, advantages and features of this application will become more apparent to those skilled in the art from the following detailed description of specific embodiments of this application in conjunction with the accompanying drawings. Attached Figure Description
[0019] The following sections will describe some specific embodiments of this application in detail by way of example and not limitation, with reference to the accompanying drawings. The same reference numerals in the drawings denote the same or similar parts or components. Those skilled in the art should understand that these drawings are not necessarily drawn to scale. In the drawings:
[0020] Figure 1 This is a schematic diagram of an IR CUT driving circuit according to an embodiment of this application;
[0021] Figure 2 This is a schematic diagram of the circuit structure of an IR CUT driving circuit according to an embodiment of this application. Detailed Implementation
[0022] It should be noted that, unless otherwise specified, the embodiments and features described in this disclosure can be combined with each other. This disclosure will now be described in detail with reference to the accompanying drawings and embodiments.
[0023] To enable those skilled in the art to better understand the present disclosure, the technical solutions of the present disclosure will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present disclosure, and not all embodiments. Based on the embodiments of the present disclosure, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present disclosure.
[0024] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this disclosure are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such terms can be used interchangeably where appropriate for the embodiments of this disclosure described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.
[0025] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.
[0026] Figure 1 This is a schematic diagram of an IR cut drive circuit according to an embodiment of this application. (Reference) Figure 1 As shown, the IR CUT driver circuit includes: a GPIO interface, a shaping circuit, and a power amplifier circuit, wherein...
[0027] The GPIO interface is used to connect to the corresponding GPIO interface of the processor and receive GPIO signals issued by the processor;
[0028] The shaping circuit is used to shape the rising and falling edges of GPIO signals into positive and negative pulse signals;
[0029] The power amplifier circuit is used to amplify positive and negative pulse signals to a level that can drive the IR CUT filter. The power amplifier circuit is built based on the audio PA chip U2.
[0030] Specifically, in this invention, the GPIO interface of the IR CUT driving circuit is connected to the GPIO interface of the CPU, and the IR CUT filter can be switched by the rising or falling edge of the GPIO signal. When the GPIO signal reaches a rising edge, the shaping circuit shapes the rising edge of the GPIO signal into a positive pulse signal for output. The power amplifier circuit amplifies the positive pulse signal, and the amplified positive pulse signal serves as the switching signal for the IR CUT filter, realizing the switching of the IR CUT filter (e.g., switching from an infrared cutoff filter to a full-transmission filter). Subsequently, the GPIO signal enters a high-level state, the shaping circuit has no signal output, the IR CUT drive circuit does not operate, and the IR CUT filter is in a stopped state. When the GPIO signal reaches a falling edge, the shaping circuit shapes the falling edge of the GPIO signal into a negative pulse signal for output. The power amplifier circuit amplifies the negative pulse signal, and the amplified negative pulse signal serves as the switching signal for the IR CUT filter, realizing the switching of the IR CUT filter (e.g., switching from a full-transmission filter to an infrared cutoff filter). Subsequently, the GPIO signal enters a low-level state, the shaping circuit has no signal output, the IR CUT drive circuit does not operate, and the IR CUT filter is in a stopped state.
[0031] In this application, the IR CUT filter being in a stopped state can also be called a held state, which means that the IR CUT filter remains stationary, in contrast to filter switching.
[0032] Furthermore, this invention uses an audio PA chip to build the IR CUT driving circuit, realizing the control of IR CUT filter switching by a single GPIO interface, which can save a lot of GPIOs and bring great convenience to the design of multi-view cameras. The driving circuit has high integration, occupies a small circuit board area, and has low power consumption. The circuit cost is relatively lower than that of the traditional dual GPIO control driving circuit.
[0033] Optionally, refer to Figure 2 As shown, the IR CUT driving circuit also includes: a connector for connecting the IR CUT filter of the peripheral device, used to send the received amplified positive and negative pulse signals to the IR CUT filter.
[0034] Specifically, refer to Figure 2 As shown, connector J161 connects to the IR CUT filter of the peripheral device.
[0035] Optionally, positive and negative pulse signals are used to switch the IR CUT filter back and forth. Specifically, when the GPIO signal is in a high or low level state, the IR CUT driving circuit does not operate and the IR CUT filter is in a stopped state. When the GPIO signal is in a rising or falling edge state, it controls the IR CUT filter to switch back and forth. The IR CUT filter switching includes switching between two types of filters: infrared cut-off filter and full-transmission spectrum filter.
[0036] Optionally, refer to Figure 2 As shown, the shaping circuit includes a first resistor R67, a first capacitor C76, and a second capacitor C75, wherein...
[0037] One end of the first resistor R67 is connected to the GPIO interface, and the other end is connected to the first capacitor C76 and the second capacitor C75 respectively. The first capacitor C76 is grounded, and the second capacitor C75 is connected to the power amplifier circuit.
[0038] Specifically, the first resistor R67, the first capacitor C76, and the second capacitor C75 form the GPIO signal shaping circuit. If the shaping circuit captures the rising edge of the GPIO signal, it converts it into a positive pulse signal output. If the shaping circuit captures the falling edge of the GPIO signal, it shapes it into a positive or negative pulse signal output. If the shaping circuit captures a high or low level of the GPIO signal, there is no signal output.
[0039] Optionally, refer to Figure 2 As shown, the power amplifier circuit consists of a second resistor R142, a third resistor R148, and an audio PA chip U2. The resistance values of the second resistor R142 and the third resistor R148 are used to adjust the amplification gain.
[0040] One end of the second resistor R142 is connected to the second capacitor C75, and the other end is connected to pin 4 of the audio PA chip U2. The two ends of the third resistor R148 are connected to pin 4 and pin 5 of the audio PA chip U2, respectively.
[0041] Optionally, refer to Figure 2 As shown, pin 5 of the audio PA chip U2 is used to output amplified negative pulse signals, and pin 8 is used to output amplified positive pulse signals.
[0042] Specifically, the second resistor R148, the third resistor R142, and the audio PA chip U2 form a power amplifier circuit, which amplifies the positive and negative pulse signals into amplified positive and negative pulse signals that can drive the IR CUT filter. The amplification gain can be adjusted by the resistance values of the second resistor R148 and the third resistor R142, thereby realizing the switching of the IR CUT filter by amplifying the positive and negative pulse signals.
[0043] Furthermore, the IR CUT driving circuit provided by this utility model can be used in the design of an EVB board for verifying a certain type of CPU chip. When verifying the ISP function of a certain type of CPU chip, an external sensor and an IR CUT filter are required during the verification. When switching between day and night application scenarios, the chip uses the IR CUT driving circuit of this utility model to drive the IR CUT filter to switch.
[0044] In addition, it can also be used in the product board design of binocular PTZ or multi-camera products. For example, binocular PTZ products have two sensors located on the main board and the sub-board respectively. The product solution is designed with the IR CUT driving circuit. Only two GPIOs are used to realize the driving control of the IR CUT functional unit. When switching between day and night application scenarios, the IR CUT filter is driven to switch through the IR CUT driving circuit of this utility model.
[0045] Therefore, this utility model uses an audio PA chip to build an IR CUT driving circuit, realizing the control of IR CUT filter switching by a single GPIO interface, which can save a lot of GPIO, bringing great convenience to the design of multi-view cameras. The driving circuit has high integration, occupies a small circuit board area, and has low power consumption. The circuit cost is relatively lower than that of traditional dual GPIO control driving circuits.
[0046] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values of the components and steps set forth in these embodiments do not limit the scope of this disclosure. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following drawings denote similar items; therefore, once an item is defined in one drawing, it need not be further discussed in subsequent drawings.
[0047] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.
[0048] In the description of this disclosure, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is generally based on the orientation or positional relationship shown in the accompanying drawings and is only for the convenience of describing this disclosure and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this disclosure; the directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.
[0049] The above description is merely a preferred embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.
Claims
1. An IR cut driving circuit, characterized in that, include: GPIO interface, shaping circuit and power amplifier circuit, among which The GPIO interface is used to connect to the GPIO interface corresponding to the processor and to receive GPIO signals issued by the processor. The shaping circuit is used to shape the rising and falling edges of the GPIO signal into positive and negative pulse signals; The power amplifier circuit is used to amplify the positive and negative pulse signals to an amplified positive and negative pulse signal that can drive the IR CUT filter, wherein the power amplifier circuit is built based on the audio PA chip (U2).
2. The IR CUT driving circuit according to claim 1, characterized in that, Also includes: A connector for connecting an external IRCUT filter, used to send the received amplified positive and negative pulse signals to the IRCUT filter.
3. The IR CUT driving circuit according to claim 1, characterized in that, The positive and negative pulse signals are used to switch the IR CUT filter back and forth. Specifically, when the GPIO signal is in a high or low level state, the IRCUT driving circuit does not operate and the IR CUT filter is in a stopped state. When the GPIO signal is in a rising or falling edge state, it controls the IR CUT filter to switch back and forth.
4. The IR CUT driving circuit according to claim 1, characterized in that, The shaping circuit includes a first resistor (R67), a first capacitor (C76), and a second capacitor (C75), wherein... One end of the first resistor (R67) is connected to the GPIO interface, and the other end is connected to the first capacitor (C76) and the second capacitor (C75) respectively. The first capacitor (C76) is grounded, and the second capacitor (C75) is connected to the power amplifier circuit.
5. The IR CUT driving circuit according to claim 4, characterized in that, The power amplifier circuit consists of a second resistor (R142), a third resistor (R148), and the audio PA chip (U2). The resistance values of the second resistor (R142) and the third resistor (R148) are used to adjust the amplification gain. One end of the second resistor (R142) is connected to the second capacitor (C75), and the other end is connected to the PIN4 pin of the audio PA chip (U2); the two ends of the third resistor (R148) are connected to the PIN4 and PIN5 pins of the audio PA chip (U2) respectively.
6. The IR CUT driving circuit according to claim 5, characterized in that, The audio PA chip (U2) has pin 5 for outputting amplified negative pulse signals and pin 8 for outputting amplified positive pulse signals.