John Xu
Member level 3
vdd ground
Hi,
I have a question on the mixed signal circuit. We are designing a 155M limiting amplifier which consists of the cascade of amplifiers and an output buffer.We treat the cascade amplifiers as analog part and the output buffer as digital part because it works like a current switch. To isolate the crosstalk from the output buffer switching, we dedicated two supplies for the analog part and digital part, seperately.
But i have no idea for the vdd/ground connection for ptat current source whcih provide the reference bias current(~uA) for the tail current(16mA) of output buffer. What do you think the vdd/fround of this ptat current source should connect to?the analog vdd/gnd, or the digital vdd/gnd?Or the dedicated another vdd/gnd for this part?
Thanks in advance
Hi,
I have a question on the mixed signal circuit. We are designing a 155M limiting amplifier which consists of the cascade of amplifiers and an output buffer.We treat the cascade amplifiers as analog part and the output buffer as digital part because it works like a current switch. To isolate the crosstalk from the output buffer switching, we dedicated two supplies for the analog part and digital part, seperately.
But i have no idea for the vdd/ground connection for ptat current source whcih provide the reference bias current(~uA) for the tail current(16mA) of output buffer. What do you think the vdd/fround of this ptat current source should connect to?the analog vdd/gnd, or the digital vdd/gnd?Or the dedicated another vdd/gnd for this part?
Thanks in advance