MAX291
Production
The MAX291/MAX292/MAX295/MAX296 are easy-to-use, 8th-order, lowpass, switched-capacitor filters that can be set up with corner frequencies from 0.1Hz to...
Datasheet
MAX291 on Analog.com
MAX295
Production
The MAX291/MAX292/MAX295/MAX296 are easy-to-use, 8th-order, lowpass, switched-capacitor filters that can be set up with corner frequencies from 0.1Hz to...
Datasheet
MAX295 on Analog.com
Goodmorning, I need a variable frequency anti-alias filter for precision ADC (due I need different output sampling rates).
I need to provide signal path for my ADC so I need a model for my anti-alias filter.
Taking as reference MAX291/295 datasheet I can reproduce MAX 295 model with python:
A0 = 4.20769896658e+29*5.77290333605
zeros = []
poles = []
poles.append(-1225.78864486+6162.45566333j)
poles.append(-1225.78864486-6162.45566333j)
poles.append(-3490.75072522+5224.27765139j)
poles.append(-3490.75072522-5224.27765139j)
poles.append(-5224.27765139+3490.75072522j)
poles.append(-5224.27765139-3490.75072522j)
poles.append(-6162.45566333+1225.78864486j)
poles.append(-6162.45566333-1225.78864486j)
k = A0
z = zeros
p = poles
# passo da zpk a tf
[b, a] = signal.zpk2tf(z, p, k)
w, h = signal.freqs(b, a) # andamento ideale del filtro
f = w/(2*np.pi)
legenda = []
#amp_mio=20*np.log10(np.abs(h))
plt.title("MAX295, fclk=50kHz")
plt.plot(f, 20 * np.log10(abs(h)))
legenda.append("F=1kHz")
plt.axhline(-3, linestyle='--', color='r')
plt.ylim(-140,20)
plt.grid()
plt.legend(legenda)
#plt.xlim(4,15)
plt.xlim(0,5000)
plt.xlabel("frequency [Hz]")
#plt.xscale('log')
plt.show()
I can't reproduce model of MAX291 due at 5 kHz (page 4, second graph) attenuation is lower than MAX295.
BTW, on that graph scale is wrong: Hz instead kHz.
How can I get model (paz) of MAX291?
Thanks.
