Hey,so I was using the following circuit(picture attached) for level shifting my GPS 2.8V signal to 5V TTL to interface with my Atmega8.
Whenever I give 5V as input to transistor 1,the 2nd transistor should theoretically be cut-off,and give me 5V as the final output. But instead I get output as 2.2V or so,which means current is flowing in the collector,even when second transistor is cut-off.
I checked Vbe for transistor 2,and its about 0.01V which suggests cut-off,but I hhave no idea why current is flowing and causing drop across my collector resistor.
Any explanations and/or remedies?