jutek
Full Member level 4
LDO again
hello
i met this problem, when i changed input voltage from 1.3 to 3.3V.
The input voltage is also supply of the opamp. I designed the opamp for the lowest value of power supply 1.3V. Dropout voltage is 0.5V
When i change Vin to 2V and set feedback resistors to give 0.9V (Vref is 0.8 ) everything is ok yet.
But when i change it to 3.3V and let feedback be the same, transient response is very improper.
For what supply values i should assign W/L ratios? The opamp is simple p-input differential amplifier with active load.
Pass device is set to be in the saturation.
thanks in advantage
hello
i met this problem, when i changed input voltage from 1.3 to 3.3V.
The input voltage is also supply of the opamp. I designed the opamp for the lowest value of power supply 1.3V. Dropout voltage is 0.5V
When i change Vin to 2V and set feedback resistors to give 0.9V (Vref is 0.8 ) everything is ok yet.
But when i change it to 3.3V and let feedback be the same, transient response is very improper.
For what supply values i should assign W/L ratios? The opamp is simple p-input differential amplifier with active load.
Pass device is set to be in the saturation.
thanks in advantage