Thanks for contacting Ask Extension with your question about low acid tomatoes. I found no specific information about the pH of cherry tomatoes. The pH of tomatoes can vary depending on soil conditions, time of year, and level of ripeness.  According to Purdue University, low-acid tomatoes are just as acidic as other tomatoes, they just have a higher sugar content which makes them taste less acidic.
     Tomatoes that are branded low-acid include  Ace, Amish Paste, Big Girl, Fireball and San Marzano. While these are not cherry tomatoes, the Amish Paste and Fireball are smaller tomatoes that may fit your needs. 

     A side note: I did find a site that recorded the pH levels of incoming varieties coming into a processing plant. Unfortunately, these varieties are not the ones used in home gardens. http://www.ptab.org/  Select 2023 top 50 varieties Hope this helps!