I'm designing a camera module using Sony's IMX224 image sensor. This module would be connected to STM32F4 discovery board. At this moment I want to make a simple camera module so that I can write program for controlling the image sensor through the STM32F4. After that I'd optimise its circuits and then make a new module
But I'm wondering if I really need 'damping resistors' for data output pins of the IMX224.
Do you need damping resistors? The IMX224 has 12 pins for CMOS parallel data output and they would be directly connected to the I/O pins of STM32F4 board. According to data sheet, people need to put a damping resistor for each data pin. But I'm not sure if you really need them. because some camera modules don't have such resistors, like the following link.
http://www.elecfreaks.com/store/ov7670-camera-module-p-705.html It has only 2 resistors. But it seems to work fine.
If you really need such resistors for impedance matching. How large resistance would you need? 10Ω? 33Ω? The data pins of the sensor have output impedance of 50Ω. I guess the magnitude of the damping resistors should depend on data rate of image sensor. But the problem is...you can change data rate after by program when you actually use the camera and then such fixed value damping resistor would make problem, or?
I'm sorry for the stupid questions. But any help would be appreciated. If I have assumed something wrong, please feel free to let me know.