I would like to implement your S7V8F3 switching step-up/step-down regulator (3.3v) to run a battery powered gsm module (ada fruit fona). This unit has a li ion battery charger circuit built and and a tap for the battery output. I want to run the battery out to your 3.3v buck/boost regulator to power the micro controller that will command the fona board. I was told that the noise from the S7V8F3 switching step-up/step-down regulator could potentially interfere with the cellular operation of the fona board. Is this something you might have information about? Is this type of circuit inherently noisy???