Design of High Speed ​​CCD Drive Circuit Based on Common Mode Choke

L0504-Murata muRata common mode inductor 90Ω 150mA

Overview:
In order to reduce the power consumption of CCD drive circuit, a design scheme of CCD drive circuit based on common mode choke is proposed. The scheme uses a CCD driver to generate a low-voltage drive signal, and then uses a common-mode choke to amplify the voltage amplitude.

Since the voltage amplitude of the CCD driver is reduced, the power consumption of the CCD driver is greatly reduced. Since the differential mode inductance of the common mode choke is small, the resonance of the capacitive load of the CCD is effectively avoided, so the scheme can ensure the quality of the driving signal. The board was designed and tested for the circuit designed by the solution. The experimental results show that the circuit designed in this scheme can effectively reduce the power consumption of the driver circuit under the premise of ensuring the quality of the driving signal.

0 Introduction Charge-coupled device (CCD) has been widely used in the field of optoelectronic imaging. It has the advantages of high speed, low noise, wide dynamic range and linear response. However, for the CCD to work properly, imaging circuit support is required. Among them, the CCD driving circuit is an important part of the imaging circuit, and the driving circuit is responsible for moving the charge packets collected by the CCD through the shift register to the output node for outputting the signal voltage. Since it is a serial shift, a high-speed drive circuit is required, and in the field of high-speed imaging, the drive circuit operates at a higher speed. In addition, the voltage amplitude of the CCD driving waveform is often very high, and the shift register of the CCD is a capacitive load. The high-speed large-voltage amplitude driving the capacitive load requires a large power consumption. Therefore, the power consumption of the CCD-based imaging system is relatively high. Large, power consumption leads to higher CCD driver temperatures, which can affect system reliability and lifetime.

To solve this problem, the CCD driver is used to first generate a low-voltage driving signal, and then use a common-mode choke to amplify the voltage. Since the voltage of the CCD driver is lowered, the power consumption of the CCD driver itself is drastically reduced. Since the differential mode inductance of the common mode choke is small, it can effectively avoid resonance with the capacitive load of the CCD, so the quality of the driving signal can be ensured.
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