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output impedance polyphase filter
The Gilbert mixer has resistor load.(400ohm)
Does the polyphase filter affect the linearity of the mixer?
does the polyphase filter requires a low output impedance buffer?
output noise ldo
What is the main contribution of LDO's large external output capacitor? Better transient response or low output noise? Or other reason?
What about some on-chip LDO with small (<100pF) onchip output capacitor,do they have sever problems?
The current gain β=Ic/Ib is almost constant for moderate bias current,but if bias current is too high or too low,the β decreases,can anyone explain it ?expecially in terms of semiconductor device,thanks.
transient responese of ldo
Thanks to all of you,some suggestions really inspired me,and I finally confirmed that the main reason for large overshoot and undershoot is due to small capacitor, not phase margin or some other things.
So,if I want to design an LDO for RF applications,off-chip large...
C1 has been connected to a voltage source V1 for a long time,at time 0,the switches switch the connection from V1 to C2,i.e. V1 is cutoff,and the two capacitor are parallel connected,what is the voltage waveform on C2?
(all the capacitors and voltage source has one node connected to groud)
I want to layout the 8:1 pnp bipolar pair,and arrange them in 3X3 square,since all of the bipolars' collector and base are connnected to ground,I use metal 1 to connect them all,and I use metal 2 to connect the emitter of the outer 8 bipolar in a circle,also use metal2 to connect the central...
When I did corner analysis,I found some parameters are not defined,but everything was OK when I simulate the same circuit without corner analysis using the same library.
The simple pcf file I loaded:
corAddProcess("tsmc018" "/eda/library/tsmc018/models/spectre" 'singleModelLib)...
ldo quick output capacitor discharge
Thanks to arghpok! The idea of bulk effect is good:)
And I have a quick glance at Robert. Milliken's Ms.C thesis, and found that actually he faced the similar problem,in worst case,the load transient undershoot is 214mV in his design.
So I think it may be...
emproved load transient response
well,I found that even if the output capacitor is more than 100pF,the transient overshoot is still larger than 100mV,why??
btw,I have adjust the miller cap in order to get PM around 60deg