This type of input stage has one potential advantage. It is that the input stage can 'source' more current than just 2I(q), which is the limitation of using a current source for a single or dual differential input pair. This can improve slew rate in many circuits.
The standard transistor input complementary differential input stage was independently developed by Jon Iverson (Electroresearch) and myself (Ampex) in the late 60's, but was not published. Daniel Meyer (Southwest Technical) was the first to publish it in the early 70's in 'The Audio Amateur'.
The FET input version was developed by me in the early 70's and first published in 'The Audio Amateur' in 1977 as part of the JC-2 schematic.
The 'diamond differential' was independently developed by Sansui in the early '80's and essentially had a single differential input stage. The same circuit can be made with fets in the complementary stage and the diodes eliminated from the circuit.
The standard transistor input complementary differential input stage was independently developed by Jon Iverson (Electroresearch) and myself (Ampex) in the late 60's, but was not published. Daniel Meyer (Southwest Technical) was the first to publish it in the early 70's in 'The Audio Amateur'.
The FET input version was developed by me in the early 70's and first published in 'The Audio Amateur' in 1977 as part of the JC-2 schematic.
The 'diamond differential' was independently developed by Sansui in the early '80's and essentially had a single differential input stage. The same circuit can be made with fets in the complementary stage and the diodes eliminated from the circuit.
I can't buy jfet and jfet seem to be "not matched each other" .Addition the break down voltage of jfet is often not high
I use 4 diode and degenerationresistor is too big => harmonics distortion is quite high with 1khz signal
I use 4 diode and degenerationresistor is too big => harmonics distortion is quite high with 1khz signal
in graph you've attached I still can see hardly any harmonic distorion
what is more 1kHz peak seems to be high
are you sure you interpret results of simulation properly or did you attach wrong graph?
what is more 1kHz peak seems to be high
are you sure you interpret results of simulation properly or did you attach wrong graph?
It looks like an FFT from an input of 1kHz and the output fundamental at probably 1.0V, although that can't be seen on the graph. That would make 2nd harmonic distortion at ~33mV to be ~30dB down, which is rather high.darkfenriz said:
33nV to 1V is down 75db in Voltage and 150db in power.
poeple
racall properties of Fourier transform !!!!!!!
1.winowed function's tranform is original tranform convolved with windowing function transform
2. Time's standard deviation*bandwith standard deviation >=1/2 (Heisenberg priciple)
If you use orcad :
edit simulation settings:
run to time: 5s or more(for adequate peak sharpness)
maximum step size: 10us or less (to prevent from aliasing)
results may be suprising...
poeple
racall properties of Fourier transform !!!!!!!
1.winowed function's tranform is original tranform convolved with windowing function transform
2. Time's standard deviation*bandwith standard deviation >=1/2 (Heisenberg priciple)
If you use orcad :
edit simulation settings:
run to time: 5s or more(for adequate peak sharpness)
maximum step size: 10us or less (to prevent from aliasing)
results may be suprising...
IF you have to use transistors only, then using 2 current sources to bias the input stage, coupled with a 100 ohm resistor between the emitter pairs would give better performance.
i will retest
oh! no! output voltage is about 20V
You seem to be not ever use orcad!
hi John Curl! Do you mean a normal fully symmetrical amp?
hi
you are sure that the input diodes are essential?
I would like to do something like this :
( UGS with only bjt)
thx
you are sure that the input diodes are essential?
I would like to do something like this :
( UGS with only bjt)
thx
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