Hi Martin, Sorry about the delay. I see that you are AC coupling the inputs. You may want to increase the input coupling caps (currently 100nF) to say 1uF. To answer your questions: 1. "Kindly also tell me about the function of Page 0 Address 3 registers bit 7 source follower and bit 1 sensor polarity." Answer : Source follower is for AC coupling (as you are doing). When enabled, input voltage range is reduced. Datasheet Section 7.4.7 discusses this about input voltage range. Page 0, Reg. 3, Bit 7 source follower enable. More positive means more white for your CIS. Page 0, Reg. 3, Bit 1 should be 0 for positive polarity CIS. 2. "In sample and hold mode my Clamp and Sample pulse should arrive at the same time?" Answer : Yes. See Figure 28. Clamping Pulses: Based on the scope image you provided (Nov. 16, 10:27PM), you are getting 8 pixels clock worth of clamping pulses. You can increase this number by using Page 2, Reg. 6-7 (input clamping start / stop). Increase the end setting to get more clamp pulses. Alignment: Based on your scope image (Nov. 17, 12:03AM), the delay pulses can be delayed a little bit relative to the sensor output as the actual event is a little earlier than what you see. You can use the little glitches on your sensor output (coincident with internal switches opening and closing) to see what is being sampled and to fine tune the alignment (as another technique to employ). OPA Buffer Application: We were not clear on what you are doing with your schematic OPA3691 (Current feedback OPA). With a current feedback amplifier, you cannot use 0ohm feedback resistor or the device will oscillate (datasheet recommends RF= 453ohm). Are you buffering the sensor output(s) for another use on your board? Regards, Hooman
↧