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Reset ICs
Reset Output Structures

Push-Pull vs. Open Drain Principles
Push-Pull Structure Open Drain Structure
Push-Pull Reset Output Structure Open Drain Reset Output Structure

A Push-Pull output consists of a pair of complementary MOSFETs. The principle is the following:

Reset output goes high when T2 turns on and T1 turns off.
Similarly, Reset output goes low when T2 turns off and T1 turns on.

ADVANTAGES:
Fast rise time
No current drained at High and Low states. Current is drained only during a switch between the 2 states.
Almost rail-to-rail response, both from Low-to-High and High-to-Low.

The Open Drain structure has only one MOSFET, which is normally turned Off.

Reset output is pulled to high level by an external resistor.
In the event that Vcc drops below Vref, the transistor will be turned on for a minimum of time (trec).

ADVANTAGE:
Wired-OR capability. Several resets can be connected in parallel.