suria3
Full Member level 5
psrr frequency
Guys,
I'm desiging a bandgap reference circuit with the opamp configuration.. I have a question here. My first design is the opamp itself. My opamp gives the PSRR (just the opamp core without bandgap circuit) of 64dB at 10kHz and 30dB at 10Mhz. Now my problem is i need to sustain at least 50dB of PSRR at 10Mhz. I'm using the folded cascode configuration with PMOS input. I guess interm of at low frequeny up to 1MHz my PSRR is 64-55dB, which i guess is good enough. My issue is on sustaining high PSRR until 10Mhz. One thing i noticed that when i add in come capacitive load at the output of cascode opamp, the frequency range does improve but i wanna to know is there any other way could be done to extend the frequency range from the circuit itself without any capacitors. Please give some input on how to improve the frequency range.
Thanks,
Suria
Guys,
I'm desiging a bandgap reference circuit with the opamp configuration.. I have a question here. My first design is the opamp itself. My opamp gives the PSRR (just the opamp core without bandgap circuit) of 64dB at 10kHz and 30dB at 10Mhz. Now my problem is i need to sustain at least 50dB of PSRR at 10Mhz. I'm using the folded cascode configuration with PMOS input. I guess interm of at low frequeny up to 1MHz my PSRR is 64-55dB, which i guess is good enough. My issue is on sustaining high PSRR until 10Mhz. One thing i noticed that when i add in come capacitive load at the output of cascode opamp, the frequency range does improve but i wanna to know is there any other way could be done to extend the frequency range from the circuit itself without any capacitors. Please give some input on how to improve the frequency range.
Thanks,
Suria
