Bidirectional Voltage Shifter Circuit is used to shift the voltage levels from low to high or high to low voltage levels.
There are two ways to implement this circuit.
1. Voltage Divider Circuit.
2. Nmos Transistor
2. Nmos Transistor Circuit: In this circuit topology you connect gate terminal of Nmos transistor to 3.3V, source and drain terminal to 3.3V and 5 V by using pull-up resistor respectively.
Up Level Shifter: Voltage at the source can be :
0V ->0 (The potential difference between gate and source is now 3.3V so the Nmos transistor conducts and on the output you get 0V)
3.3V ->1 (Gate and Source both are on same potential so the potential difference between gate and source is now 0V and transistor is in off state so the 5V are pulled up by resistance and you get the 5V at output)
Down Level Shifter: Voltage at the drain can be :
0V ->0 (The drain is at 0V so the body diode of transistor conducts and transistor is in on state so we get 0V at the source)
3.3V ->1 (Drain terminal at 5V so the transistor is in of state and we get 3.3 V at the source terminal pulled up by resistor)
0 Comments