The DS80C400 Network microcontroller is designed for operation at a Vcc of 3.3 volts. The part has a high active reset input.

The MAX700/701/702 part series is NOT suitable for use on the DS80C400 since this part series is designed for use on microcontrollers which operate on 5 volts. (The MAX700 could be made to work if an external resistor divider is used to set the detect threshold).

The MAX709L/709M parts are not suitable for the DS80C400 since the sense threshold voltage level is above the 3.3 volt level. As such the microcontroller would be in continuous reset state.

The MAX709R/709S parts have a sense threshold that is below the 3.0 volt lower legal limit of the Vcc for the DS80C400. As such a power supply brownout to below 3.0 volts may lead the microcontroller into erratic operation before a RESET pulse is generated.

Only the MAX709T with a sense threshold at 3.08 volts is suitable for use with the DS80C400 microcontroller.

There are other reset controllers from MAXIM that may be better choices for use with the DS80C400. Look into these parts that are made more specifically for 3.3 volt microcontrollers...

DS1832, DS1819, DS1708T

Michael Karas