• Resolved

ISO7710: Power-up delay

Part Number: ISO7710

Hi, 

Am designing a board where i need to isolate some digital inputs. This design suppose to replace a part of an old design (a new daughter board for an existing mother board).

The inputs to this board are logic signal out of micro controller and the customer request that those outputs need to be electrically isolated from the daughter board. The problem is there is no ground signal, the old design just use a 5V rail and the i/o of the micro-controller as an open-drain with pull-up. This situation will be perfect for an opto-coupler but this open-drain is not capable of 20mA

So what am planing to do is to use the ISO7710 as isolator and power up the ISO7710 from this 5V and the this logic open-drain (VCC1 will be wired to 5V, GND and IN will be linked to the OD input, VCC2 is always powered up). i will use the model with default output high so when VCC1 is off it will have the same effect of the pull-up resistor when OD is off.

Signal speed is not high. But didn't find any information about power-up delay, since basically the device will be switching on and off. instead of toggling IN logic level.

Thanks.

Hamdi.