Search Engine

28 Threads found on Input Capacitance Measure
Hi everyone, Can someone explain to me what's the best way to simulate and get the input capacitances of aa mosfet? More, if I want to know the Cgs and Cgd how I can I do that? All this using cadence. Regards.
Here I used HF CT to measure current on ground strap and large capacitance transformer ( not shown) to measure 50~100kV voltage impulse with C ratio that scales voltage down to safe levels for 50 Ohm termination inside scope. High quality coax is critical. Here V impulse is 10V input 50 Ohms or 2 watts which when (...)
Hi everyone, I am a newbie in Cadence spectre simulator. I have a 2 ports network and I try to plot the input equivalent capacitance vs. frequency. In ADS I use equation: Cin = imag(Y11)/2/pi/freq. But I don't know how to insert that equation into Cadence. I only used a basic SP analysis. I have read many thread but I cannot find the answer.
The following demo code utilizes the CTMU to measure the value of a capacitor attached to an ADC input channel: Charge Time measurement Unit (CTMU) In this code example, CTMU module in PIC18F4685 is used to calculate the capacit
Hi i am trying to measure the input and output capacitance of a buffer stage (for example) as i need to measure several other stages i set up the following circuit 104476 and i set the input voltage to 1.2 with AC Magnitude and Amplitude to 1.2 , also vdd is set to 1.2 then i calculated Zin = (...)
Hi, You can measure the delay between Buffer input and Buffer output.. And actually it is a sum of inverter delays.. Thanks
If this capacitor is series you should add an inductor in parallel.If it's parallel, you should add an inductor in series. Depends on capacitance configuration. But I'm not sure that the input impedance becomes purely capacitive.Because SAW filters generally have an input impedance with a real part by their nature. There might be a (...)
No load instability is common in SMPS and 10% pre-load activated by current sensor, may be needed. Overall open loop phase margin should be analyzed to improve stability to determine which capacitance and/or input ESL affects the results. Alternatively put on the minimum load for stability and measure the % overshoot on step loads and (...)
I remember doing something similar once, but there is a simpler way to get the input capacitance of an inverter if you'd like to do back-of-the-hand gate delay calculations and stuff. Create a chain of inverters as shown in the figure attached. Now, you can use the optimization routine in HSPICE or vary Cdelay till the delay from nets c to g (c
Hi, I'm trying to measure input capacitance of simple inverter, and I have some problem... Using the following statement: .meas ac Cdb max(I(Vin0)/(2*3.1415*frequency)) Result of this measure is ok, but it is in dB, and I don't know how to translate it to linear scale. I tried something like this: .meas ac Cin (...)
Hello, I'm making a very low bandwidth 40MHz receiver. The receiver is fairly simple: an LC input filter and two FET gain stages go into an ADC. I'm using an "electrically small" strip-line antenna which of course has a tiny input impedance: ~1.96 -j1758. Do I need to add a matching network even though it's at such low frequency? The antenna is
I don't know the LM2101: what is it ? However where do you measure the distorted waveform, at the output of the LM2012 (gate of IRF520) or at the output of the circuit (I presume the 50 ohm resistor) ? In the first case, take into account that the IRF520 has a quite high input capacitance (350 pF), it could be that LM2101 is not able to (...)
If you measure V1 with a DVM, this will have a 10 megohm input impedance so the extra current, will be very low, and as you know its a 10 megohm resistor you can compensate for it in your calculations. Frank
I'm using SP720 for analog circuit protection in a number of instruments since about 10 years. I must confess, that I didn't yet measure the devices crosstalk capacitance (input pin to input capacitance), but I won't expect a value above 0.1 pF or so. In other words, the external circuit crosstalk (...)
Hi people, I wanted to ask whether anyone here could suggest me the method to measure the input capacitance of a MOSFET in cadence or in ADS. falcon
Hi everybody. Is there anyone how can guide me to measure input parasitic capacitance with HSpice simulation? Thanks in advance. Alireza
Im measure adc pin with a multimeter but it gives good values. So the problem is either with your code, or the analog input pin is damaged. I tried feedback capacitance but nothing changed. Yes, an oscillating OP output should still give an ADC signal. Simply keep in mind, that a compensation cap will be necessary f
The question is about a real measurent rather than simulation, if I understand right. In this case, the usable resistor frequency range is mainly limited by it's parallel capacitance. For 1 MOhm, it will be a few MHz at best. On the other hand, the "current source" resistor must be large compared to the TIA input impedance in the frequency (...)
Do a simple tran.. measure the input cap of both the switches or just the second switch.. that can be considered as the load for the prev stage..and then resize your previous stage to meet ur timing.
Hello Edaboarders, I need help regarding the using of Spectre to know: How to mesure gm of a circuits ? How to measure the input/output capacitance and resistor of a circuits ? How to plot the caracteristic of a varactor ? 50 pts to be given for helpers. Merci.
The answer is simple and easy: Use the definition of the parameter you want to simulate. In your case: According to the definition of the transconductance you should measure (simulate) the change in output current devided by the corresponding change in input voltage. By doing this, you have two alternatives: 1.) DC analysis: Simulate the output-i
hi wangkes9, i think the input cap. includes cgs and miller cap. of cgd. in general the input transistor works in strong inversion region, so cgs is equal to 2/3*w*l*cox+cov, and the miller cap of cgd is cgd*(1-A).
Not simulation. I want to know some input pin's capacitive loading. Just probe the input pin and gnd using RLC meter? Is it ok?
Increase the input voltage linearly, and measure the input current. Then C = I / (dV/dt) Vin in 0 pwl 0 0.0 10n 2.5 .meas tran imax min I(Vin) .meas tran Cin param = '-imax / (2.5/10n)' .tran 10p 10n
Hello, I wish to measure circuits at high frequencues (~10-30 MHz), I was wondeirng if anyone could possibly outline a method of accurately measuring the input impedance & capacitance of an oscilloscope probe so i can have some confidence in the measurments I take. How can i cancel out the impedance/capacitance effect (...)
Combination of 1kΩ resistor in series and 15pF probe input capacitance gives about 10MHz -3dB frequency. measurement accuracy will be poor.
You can consider a Schottky diode to be a large signal device. That is, its impedance can vary drastically as the RF power incident on it increases. If very little power is incident, the diode is reverse biased and looks like a very small capacitance. If enough power is incident, the diode conducts current for part of the input sine wave, an
in hspice or spectra, does anyone know hot to get or calculate the input capacitance value(Cin) of a I/O cell? help me. thx!