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A constant gm is an important block in gm-C filters. For maintaining the filter response across PVT, gm of the OTA needs to track a fixed gm. There are other circuits also available where one needs gm tracking.
Neither; usually they're fairly lousy regulation (if any). Nobody cares since they only have to charge the battery without burning it up (and the phone has some smarts about that, inside). But I have used many of them, with some added filter caps and a 3-terminal regulator, to make low cost (wall wart is free when the thing it powered, died) powe
Hi everyone I have designed a coupled-line filter at X-band using Ro-4003 with 8mil of thickness. Rogers Software (MWI-2016) suggests dielectric constant of 3.81 for this substrate, this thickness, and at X band. this number has significant difference with popular dielectric constant for RF design using RO4003 (I mean 3.5
At the output i am using 1kOhm and 102 to filter. 102 means 1 nF? 1k*1nF = 1?s time constant = low pass cut off frequency 160 kHz. How should it filter 20 kHz pwm? Secondly, why are you stepping through the sine table up and down alternatingly? Makes no sense. A sine full cycle should be repeated continuously, either up- or downw
The usual way to setup the DC bias is to keep the negative feedback path and filter it with a very large time constant, e.g. capacitor of 1F, 1000F, whatever is appropriate.
PSK is usually NOT constant envelope. Think of a BPSK signal, when it goes from zero to 180 degrees....the signal has to go thru the origin...i.e. momentarily it has zero amplitude, especially if there is any sort of bandpass filter in the path. So passing it thru a non linear amp will have degradation. You could try it and see if the degradat
You have to add ~8bit on top of high frequency range to avoid phase jitter, which brings 24 bits you have calculated to 32 bits. Sounds like a misunderstanding of DDS principle. You can get pretty low jitter after the DDS output filter with a carrier fulfilling the Nyquist criterion, achieving low jitter is much more a problem of s
I have a circuit of low pass filter. the input is 0 to 2.5 Volt. i need the output is 1 volt as DC signal. and I need the values of the R1, R2, R3 and C1. How much should be? the circuit analysis please. M_kuty 125625
In the attached image,What is the application of R3 and C1 in the feedback it used as an integrator circuit or to filter any noise?Will this have any impact on the rise time of the output driver circuit? Also how can we calculate the output voltage of opamp if we vary the input voltage at the non-inverting pin of opamp? [ATTACH=CONF
R9 is a load on the sensor output. R8/C16 are a low pass filter to reduce fast variation in the measured voltage (= average it over a period) so it gives a more constant reading. The pin on the IC will be an analog input to read the voltage. Brian.
O.K. PWM with a RC filter. Which values? PWM frequency? Where do you connect the OP? How's the OP output loaded? LM324 is probably too slow for the application (has bandwidth and slew rate limitations). To extend PWM DAC frequency range, you'll preferably use a higher order low-pass filter with well considered cut-off frequency. There must be of
Hi, Can any one suggest me to remove the poles in CMFB circuit loop in differential opamp. This poles are appeared due to the filter feedback network. The CMFB circuit has shown below, and Loop gain and phse shift. I noticed that SR did not change in the filter due to instability of CMFB. 117712
I can't understand how S11 can be constant, while S21 changes (in software simulation). For example, same filter with small adjustment in configuration: configuration1: S21=-2.5dB, S11=-11dB configuration2: S21=-2.5dB, S11=-17dB If i use real measurements with network analyzer, would it be similar? Where that 17dB-11dB=6dB comes from if S21 i
How do I design a 1st order filter with 2 second time constant? 1 / (s + ?) Once i have it in continuous form I can convert using BiLinear and design the digital filter I need.
Dear all, I have design a filter bank, consisting of 6 low pass filters with different cut off frequencies. Each filter is sandwiched in two relays. Relays have 50ohm contact resistance. problem is when I connect my 50Watt PA at the input of this filter bank, some filter relays start buzzing and I have (...)
Hi everyone, I am trying to sort out a design that has following line Pin -> VGA -> gain block -> driver amp -> PA -> filter -> directional coupler (coupled signal fed back to VGA control) -> diode PIN switch -> Relay -> Pout Now problem is that PA can deliver and does deliver 48dBm when filter is not in loop but as soon as the (...)
WIthout seeing the circuit, the problem with this design is that the photodiode appears to saturate with 3V across the current sense resistor and then the recovery time is extended, also as the current drops the RC time constant increases The second problem is that the filter BW should match the signal content for optimum SNR to reject ripple. Som
Hi, One problem might be that a square signal includes the odd number frequencis of overtone. So a 500 Hz square includes 1500, 2500 ... Hz also. It depends on your detector whether it can recognize your desired frequency or not. How did you build your detector now? When using bandpass function then use the output with the highest amplitude for
The series capacitors in a crystal ladder filter are needed for tuning at various frequencies offsets from the central frequency of the filter. Also they affect somehow the input/output impedances of the filter, so the parallel capacitors needs to be adjusted in the same time with the series ones, to keep impedances (...)
I need a little help here. I want to implement a Highpass filter that outputs a continuous voltage waveform. Thanks It is a very simple high-pass - in principle, first-order only. If you are satisfied - good enough. Otherwise, you should use one of the classical forms for high-pass networks (passive or active).