Today I’m pleased to introduce a new FPGA mezzanine card (FMC) that we are on the verge of releasing to the market. Due to growing demand from our customers, we created a new version of our MI125 FMC called the MI125WB. The “WB” stands for wideband – the new version is compatible with the original one in all regards (both software and hardware) but has an analog bandwidth of 250 MHz.

The MI125 FMC is a 14 bit, 125 MSPS, 16 or 32 channel phase-aligned analog-digital converter (ADC) board. This board is already great for many applications like medical or industrial imaging and multichannel digital acquisition (DAQ) systems. The MI125 is designed around the LTM9012 ADC module from Linear Technology. This ADC module enables the MI125 to have outstanding performance in the first Nyquist band (0–62.5 MHz). But with an analog bandwidth of 90 MHz, it is not ideal for working in the 2nd Nyquist band or higher.

With this in mind, we launched a project to design a new analog front-end for the MI125. The main goals of the project were:

  1. Widen the analog bandwidth to 250 MHz while keeping the performance in the first Nyquist band as good as possible
  2. Minimize software modifications

We replaced the LTM9012 ADC modules with LTC2175-14 ADCs as well as our stage of ADC drivers. A huge advantage of the LTM2175 ADC is that it has the exact same internal registers as the LTM9012. This was very important to us since it makes it possible to reuse all the MI125 software without any modifications, thus speeding up the development process tremendously. It will also make it easier for customers to replace their MI125 for a MI125WB should their application benefit from it. All that will be required is to upgrade the firmware of their Perseus to the version available in the soon-to-be-released version 6.5 of the ADP Software Tools – mTCA Edition.

Once we received the new MI125WB hardware, we quickly confirmed that almost no modifications would be required as far as software was concerned. Unfortunately initial tests demonstrated that we did not meet our analog performance targets. After tweaking the analog front-end of the card we ended up with a configuration yielding very good performance results.

Table 1 summaries the preliminary MI125WB performance results in an AC-coupled, single-ended configuration.

Frequency

SNR

(dB)

THD

(dB)

SFDR

(dB)

Near-channel crosstalk (dB)

Far-channel crosstalk (dB)

48 MHz

62.4

–70.9

–71.5

–66.9

–85.1

76 MHz

61.5

–70.7

–71.8

157 Mhz

59.3

–58.9

–64.1

199 MHz

58.0

–46.7

–51.4

–56.6

–73.3

Table 1: Preliminary analog performance of the MI125WB

Figure 1 shows a comparison of the MI125 and MI125WB analog bandwidths.

Figure 1:  MI125 and MI125WB analog bandwidth

Figure 1:  MI125 and MI125WB analog bandwidth

If the MI125WB suits your needs, please contact us and we will let you know everything about when you can get one and start working with it.