AnsweredAssumed Answered

Why there is no imroved single channel isolated RS232 interface than ADM3251E?

Question asked by Hemant on May 30, 2012
Latest reply on Jun 1, 2012 by Hemant

I have expressed a need a few days ago on this forum to solve my difficulty in using ADM3251E in an application that needs a large number of isolated RS232 channels, owing to its poor conversion efficiency and high idle  current. Hence I arrived at a 2-chip solution with the help of Paul. One chip provides isolation and power, and the other just provids level conversion between isolated TTL and RS232. The isolated power device is 100 mA device which is much more efficient than AMD3251E and has low idle current.


My question is -- why has AD not come out with a successor to ADM3251E with better conversion efficiency when they have the technology? Why did they come out instead with a device with 2 channels in ADM3252E which has better efficiency, but is more than $ 8 compared to the $2.99 for the inefficient ADM3251E?  Do they expect us to take such quantum jump in pricing? Won't it be better to have an efficient single channel chip as a sequel to the ADM3251E than using a 2-chip solution especially when one has to handle a large number of independent isolated RS232 channels? I need 9 or 16 isolated Tx/RX channels and dread at using a 2-chip per channel solution finding it to be cumbersom. Unfortunately my only other alternative seems to be the inefficient ADM3251E just to save the chip count and PCB real estate.


Can someone from AD explain?