Features: Using the principle of switched capacitor filter can build L P/H P/BP/NO filter. Inside contains two identical filtering unit A/B, each unit is two filter, so a MAX262 can constitute fourth-order filter. Four parameters need to be used: center frequency f0, Q value, clock frequency, work mode. Filter type (L P/H P/BP/NOTCH) is determined by pin connection, the cut-off frequency f0 is determined by fclk and FN parameter, the Q value is determined by QN parameter. Parameter determination can be more accurate, but it is switched capacitor filter, so output waveform is ladder form, the common method is to add a RC low-pass filter out high frequency clock signal. Input and output have two SMA interface INA, INB, VOUTA, VOUTB, outputs A and B can be cascade connected by jumper wire P1 to realize fourth-order or other form of filter. Specifications: Model: MAX262 Power Supply: Typical +5V Size(L*W): 7.5*5cm/3*2in Weight: 23g(approx.) Detailed Description: 1, Four modes Mode 1 bandpass, low pass. Applicable type Butterworth, Chebyshev, Bessel. Can also be used for band-stop filter. Mode 2 whole pole bandpass, low pass Mode 3 ellipse bandpass, elliptic low pass, high pass Mode 4 All pass 2, FCLK input by CLKA/CLKB pin, can change filter cutoff frequency fo with parameter FN together. 3, FN value is for F0, decimal representation of Q binary values. Center frequency range 1HZ-100KHZ, MAX262 center frequency is up to 140KHZ. Center frequency or break frequency calculation method: Mode 1, 3, 4:Fclk/f0=(26+N)pi/2; Conversion to f0=fclk*2/pi/(26+N) Model 2:N= fclk/f0/1.11072-26 QN value range is 0.5-64.0, biggest model is up to 90 Q value control word calculation method: Mode 1, 3, 4: N=128-64/Q Mode 2: N=128-90.51/Q 5, work mode, FN, QN can be saved in the internal ROM of MAX262 by address cable, data cable, control cable writing operation, thus make the system work. Select A0-A3, ROM data will be updated, D0/D1 are data position.Data is written in at WR signal rising edge.Fclk input end electric signal will not produce interference to digital signal end. Details: 1, Single chip microcomputer to MAX262 connection with middle latch/trigger can significantly reduce the interference. 2, There are two methods to set frequency f0: Method 1:FCLK is fixed, change the value of FN.Because FN scope is only (0-63), the stepping value is small and low accuracy. Method 2:FN is fixed, change FCLK. Adjusting FCLK can get satisfactory cut-off frequency. Package Includes: 1 x Filter Module 1、Using the principle of switched capacitor filter can build L P/H P/BP/NO filter. 2、Inside contains two identical filtering unit A/B, each unit is two filter, so a MAX262 can constitute fourth-order filter. 3、Four parameters need to be used: center frequency f0, Q value, clock frequency, work mode. Filter type (L P/H P/BP/NOTCH) is determined by pin connection, the cut-off frequency f0 is determined by fclk and FN parameter, the Q value is determined by QN pa 4、Parameter determination can be more accurate, but it is switched capacitor filter, so output waveform is ladder form, the common method is to add a RC low-pass filter out high frequency clock signal. 5、Input and output have two SMA interface INA, INB, VOUTA, VOUTB, outputs A and B can be cascade connected by jumper wire P1 to realize fourth-order or other form of filter.