Simple Large Fan-In AND Gate circuit
We can make simple Large Fan-In AND Gate circuit by one Voltage
Comparators from circuit below
Vout = A and B and C and D and ….
This circuit is application of LM139
Low Power Low Offset Voltage Quad Comparators
The LM139 series consists of four independent precision
voltage comparators with an offset voltage specification as
low as 2 mV max for all four comparators. These were
designed specifically to operate from a single power supply
over a wide range of voltages.
All pins of any unused comparators should be tied to the
The output of the LM139 series is the uncommitted collector
of a grounded-emitter NPN output transistor. Many collectors
can be tied together to provide an output OR’ing function.
Vo = A or B or C