Hello,
This is my first post so I'm sorry ahead of time if I'm missing key information.
I am trying to produce a clock signal for a HI7190 (ΣΔADC) using a 10MHz quartz crystal oscillator. The HI7190 uses either 2-Wire or 3-Wire (SPI-compatible) communication for reading and writing internal registers. It seems mine is responding correctly by driving its Data Ready Pin low to let my microcontroller know it has valid information ready. However, it only responds with random bits, mostly flat 0's.
At first, I was using a 4MHz CMOS compatibe(-ish) clock signal from the ATmega32u4 I am using to control the ADC. It wasn't a pretty squarewave signal by any means, so I decided to try a quartz crystal oscillator instead, connecting it to the ADC as shown in the datasheet (directly to the OSC1/2 pins). I probed the crystal on the OSC1 pin (clock signal input) but my oscilloscope shows only a flat 0Vdc. I tried connecting a 1MΩ resistor in parallel with the crystal, and I do now have a clean 10MHz sinusoidal signal. However, it is by no means CMOS compatible as it sits at 1.7Vdc with a ~135mVac signal on top.
I'm not sure what to do at this point, so any advice would be much appreciated! Let me know if I should post any more info.
Thanks!
This is my first post so I'm sorry ahead of time if I'm missing key information.
I am trying to produce a clock signal for a HI7190 (ΣΔADC) using a 10MHz quartz crystal oscillator. The HI7190 uses either 2-Wire or 3-Wire (SPI-compatible) communication for reading and writing internal registers. It seems mine is responding correctly by driving its Data Ready Pin low to let my microcontroller know it has valid information ready. However, it only responds with random bits, mostly flat 0's.
At first, I was using a 4MHz CMOS compatibe(-ish) clock signal from the ATmega32u4 I am using to control the ADC. It wasn't a pretty squarewave signal by any means, so I decided to try a quartz crystal oscillator instead, connecting it to the ADC as shown in the datasheet (directly to the OSC1/2 pins). I probed the crystal on the OSC1 pin (clock signal input) but my oscilloscope shows only a flat 0Vdc. I tried connecting a 1MΩ resistor in parallel with the crystal, and I do now have a clean 10MHz sinusoidal signal. However, it is by no means CMOS compatible as it sits at 1.7Vdc with a ~135mVac signal on top.
I'm not sure what to do at this point, so any advice would be much appreciated! Let me know if I should post any more info.
Thanks!