Questions tagged [differential-amplifier]
For questions about circuits that amplify the difference between two input signals but not the signal common to the two inputs (e.g. the long-tailed pair). Do not use for questions about operational amplifiers (which are a type of difference amplifier) unless the op amp is used as a differential amplifier -- use only the "operational-amplifier" tag for most questions about op amps (e.g. an op amp as an inverting amplifier).
379 questions
1
vote
1
answer
112
views
Fully differential amplifier input voltage limit
I am exploring amplifiers for converting single ended signal from a scientific detector to a differential signal to be read by an ADC. A few FDAs I have explored have quite low limit on the ...
- 129
0
votes
2
answers
61
views
CMOS Current-Mirror Operational Amplifier Output Stuck at Rail in LTSpice
I am trying to simulate a differential amplifier I came across reading Microelectronics: Circuit Analysis and Design-Donald A. Neamen.
The circuit is:
Changing V3, V4, and the tail current seems to ...
- 25
1
vote
0
answers
79
views
Current measurement of active clamp flyback
I am working on a 50 kHz active clamp flyback which uses ZVS. The schematics look like this: https://www.researchgate.net/figure/Active-clamp-FlybackACF-Converter_fig1_333427620 (Figure 7 in DOI 10....
- 135
1
vote
4
answers
154
views
Understanding what is meant by the word 'common' in the term 'common mode voltage'
I have a bit of a silly question regarding common mode voltage. Specifically, when I think of the word 'common' (and its English meaning), I find that that the common mode voltage definition (\$V_{\...
- 299
1
vote
2
answers
135
views
How to solve lowered input impedance due to divider biasing with single supply BJT difference amplifier?
circuit design.
Hi! I have built the following single supply BJT difference amplifier. The quiescent current is 2.5uA, Vcc is 5V and Vee is 0V.
The emitter impedance is $$re=\frac{V_t}{I_e}=\frac{25....
- 270
-2
votes
2
answers
277
views
Converting a differential signal into a single-ended signal
I have to make an isolated voltage sensor using an isolated amplifier (AMC1300, link to its datasheet). It produces a differential output centred around its common mode voltage, \$1.44V\$ ...
- 392
0
votes
1
answer
130
views
Differential amplifier common-mode gain
How do you find the common-mode gain of this circuit? \$\lambda > 0\$, and \$g_mr_o \gg 1\$. Using \$A_v=-G_mR_\text{out}\$.
2
votes
1
answer
125
views
Common mode noise rejection improvement whne converting single ended to differential signal using disscrete implementation or FDA
I am designing ADC driver for LTC2325. The signal to be read is an output from a scietific detector which is single ended. The preamp driver and ADC are part of detector controller which is planned to ...
- 129
1
vote
1
answer
152
views
Difficulty implementing differential output stage
I’ve developed an elliptical circuit followed by 3 op-amp stages. The final output needs to go into an LPC4370 ADC (can’t be changed), which requires a differential input (100 mV to 900 mV range). I ...
- 99
0
votes
1
answer
55
views
WSH202linear hall sensor
I'm trying to use WSH202 (hall effect sensor). It has two output pins so I can use it in differential way.
I'm powering it with 5V and the output of each pin should be 0 ~ 4.8V. Vout1 should be rise ...
- 11
2
votes
4
answers
322
views
How to increase sensitivity of this current sensing circuit?
I have a current sensing subcircuit, but the differential amplifier's gain is very low.
The output is taken between collectors of Q2 and Q1. I would like to lower the current sensing resistance to 10 ...
- 323
1
vote
0
answers
64
views
Input common mode for a switched capacitor integrator
I had a question about finding the input common mode of a differential switched capacitor integrator (shown in the figure below).
The integrator is a conventional delaying integrator with two non-...
- 21
1
vote
3
answers
178
views
How to calculate the outputs of a Fully differential amplifier?
I’m trying to understand how to calculate the outputs of a fully differential amplifier, as shown below:
My approach is to conceptually split the FDA into two paths and analyze each output separately....
- 57
1
vote
0
answers
40
views
Does increasing drain current cause decrease in source to gate voltage of PMOS
Suppose that VIN(+) and VIN(-) have dropped by ΔV. This causes the source-gate voltage (VSG) of Qp2 and Qp3 to increase, which in turn causes their drain current to increase. Since the current source ...
0
votes
2
answers
99
views
what is the difference between FB pin and OUT pin in a FDA(Fully diff. Amplifier)?
I’m currently working on building a low-frequency thermometer, and as part of that, I’m studying a design described in a paper. My goal is to replicate the circuit and eventually improve upon it.
The ...
- 57