Hi, I think I should use DSP or mixed signal processor (IC) for the needs mentioned below. I'm going to ask may be simple, but I'm inexperienced in choosing materials and processors. Is there a product in AnalogDevices that I have specified the characteristics of below? I would appreciate it if you could share the relevant information and documents with me, if any.
We have 1 Laser sensor for our industrial vehicle application. We want to detect pulse signals from the laser sensor that are below between 5-10 ns. Our sensor current is between 20uA - 100uA. We want to do this detection with a DSP or mixed signal processor.
If possible, we would like to have a TIA circuit inside the DSP or mixed signal processor (IC) that can be adjusted for gain. The gain settings of the TIA can be made by software from inside the IC or they can be applied by switching to the software by placing external components on the outside of the IC.
At the TIA output, filtering is required for the signal. It is necessary to use High pass filter (HPF), Low pass filter (LPF), band pass filter (BPF). This filter and/or filters can be cascaded inside the DSP or mixed signal processor (IC). If possible, the LPF, HPF, BPF filters should also be of a structure that can be switched and cascaded in a DSP or mixed signal processor (IC). After these cascaded filters are connected, the amplitude of the pulse signal should be a pulse of <10ns with a voltage of 5VDC. That is, 5V, which can be detected from a DSP or a mixed signal processor (IC), should become a pulse signal.
If it is not possible to do the above approach in a single DSP or mixed signal processor (IC), the solution can also be produced by connecting the cascade “DSP or mixed signal processor with TIA” and “DSP or mixed signal processor with filter”.
We plan to use CAN BUS as the communication interface at the DSP or mixed signal processor (IC) output. If there is no CANBUS interface, an isolated converter circuit can be added to the CANBUS interface and the CANBUS interface can also be obtained. Or UART can also be used if there is UART support in DSP or mixed signal processor (IC). CANBUS is our first choice.
We want to make a system as seen in the photos. But we couldn't find any IC that contains all these (TIA, Filter, Buffer).
In the last case;
- Is there a DSP or MCU that will meet the specifications I wrote above? What are your suggestions?
- MSP430F2311 says TIA gain bandwidth is between 1.4 MHz and 4 MHz. GBW value in the Stm32g series is between 7-13 MHz. Since I could not find an example from AnalogDevices, I wanted to give an example of them. In this case; Is the TIA sufficient for us to detect pulses smaller than 10ns? Or is bandwidth important here?
We think that the transimpedance amplifier should have a GBW value of 100MHz.
- If the bandwidth is important here and it is not enough, can we solve it with a timer, interrupt-like hardware in the MCU? If it is not enough; How do we calculate this bandwidth (gain bandwidht)? How should it be determined?
Thanks in advance.