ISO122 vs ACPL-C87B-000E

Now i have a analogic signal (0-4V) connected to 7061ADuC.
Now I need to isolate this signal from 7061ADuC.

ISO122 for me it's perfect and easy but i haven't +15-15V in my board (the board is small so i can add only dc-dc converter isolated like NTE0505MC) so i must choose ACPL-C87B-000E
My goal is the 7061ADuC.. must not "read" different values with or without Isolated amplifier.
What's your opinion?

I am having a problem understanding your question. The data sheet states: The ISO122 is easy to use. No external components are required for operation. The key specifications are 0.020% maximum nonlinearity, 50-kHz signal bandwidth and 200-V/°C VOS drift. A power supply range of 4.5 V to 18 V and quiescent currents mA on VS1 and ±5.5 mA on VS2 make the ISO122 ideal for a wide range of applications. Your schematic does not show the power supply and associated connections plus I cannot read it it is fuzzy. Can you restate your question with more information.

From datasheet Iso122 works with this power supply:
+- 4.5V to +-18V

In my board i have only +5V and i can't add more dc-dc converter (it's very small)
I need "replace" ISO122 with a other component

Now the board hasn't a isolated amplifier but I have to put it