Freakwency
Newbie level 4
Hi there, somebody please help:
I have a voltage buffer with an open-drain output stage(NMOS) as shown below. The simulation shows good tracking of the output voltage(with respect to the input voltage) but now I got the silicon and the buffer seems to have problem tracking the input when the voltage is close to the power supply(VDDH). In other words, the NMOS cannot turn-off when the input is close to VDDH and there are leakage currents. Can anybody tell me what the possible cause is? Thanks!!
I have a voltage buffer with an open-drain output stage(NMOS) as shown below. The simulation shows good tracking of the output voltage(with respect to the input voltage) but now I got the silicon and the buffer seems to have problem tracking the input when the voltage is close to the power supply(VDDH). In other words, the NMOS cannot turn-off when the input is close to VDDH and there are leakage currents. Can anybody tell me what the possible cause is? Thanks!!