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Hello everyone, I'm performing the verification of a simple Sample and Hold implemented in SystemC-AMS. The Sample and Hold is modeled with the MOC ELN, the MOC TDF input signal source, and Sample and Hold output a port for the discrete domain. When the sample switch is closed for a long time the circuit has a low pass filter behavior, so the check consists of finding the cut-off frequency in this situation through the voltage gain (v_out / v_in = 0.707). However, this gain is only being achieved with frequencies much larger than the cutoff frequency. Codes are shown below Can anyone help? The V_in and Vout measurements are made by the read () method on the input signal "sc_core :: sc_signal <double> adc_in_source" and "sc_core :: sc_signal <double> adc_out". Thank you in advance. #include <systemc-ams.h> #include <cmath> class sample : public sc_module { public: sca_tdf::sca_in < bool > ctrl_lp; // CAPCOM input for the switch sc_in < double > in_src; // Analog signal input from the MUX sc_out < double > out; // Sampled signal output sca_eln::sca_tdf_rswitch key; // Switch ideal. Simulates sample switching. sca_eln::sca_node n1,n2,n3,n4; // electrical nodes sca_eln::sca_node_ref gnd; sca_eln::sca_c CI; // Low-pass filter input capacitance sca_eln::sca_r RI; // Internal filter resistance low pass filter sca_eln::sca_r RS; // External source resistance sca_eln::sca_de::sca_vsource vin_src; sca_eln::sca_de::sca_vsink vout; sample(sc_module_name name) : sc_module(name) , CI("CI") , RI("RI") , vin_src("vin_src") , vout("vout") , RS ("RS") , key("key") { vin_src.inp(in_src); vin_src.p(n1); vin_src.n(gnd); RS.value = 0e3; RS.n(n1); RS.p(n2); RI.value = 2e3; RI.n(n2); RI.p(n3); key.p(n4); key.n(n3); key.ctrl(ctrl_lp); key.ron; key.roff; CI.value = 40e-12; CI.q0 = 0.0; CI.p(n4); CI.n(gnd); vout.outp(out); vout.p(n4); // Vout.tdf_voltage(out); vout.n(gnd); } ~sample(){} }; #ifndef SRCS_H #define SRCS_H # include <systemc-ams.h> SCA_TDF_MODULE (srcs) { sca_tdf::sc_out<double> out_tdf_de; // output port srcs( sc_core::sc_module_name nm, double ampl_, double freq_, sca_core::sca_time Tm_) : out_tdf_de ("out_tdf_de") , ampl(ampl_) , freq_1(freq_) , Tm(Tm_) {} void set_attributes(); void processing(); public: double t; double ampl; // amplitude double freq_1; // frequency double data;// setup_param; int setup; sca_core::sca_time Tm; // module time step }; #endif // srcs_H #include "srcs.h" #include <cstdlib> /// for std::rand #include <cmath> void srcs::set_attributes() { set_timestep(Tm); } void srcs::processing(){ t = out_tdf_de.get_time().to_seconds(); // Get current time of the sample data = (ampl/2)*sin((2.0 * M_PI * freq_1 * t)) + ((ampl/2)); out_tdf_de.write(data); // Write value on output }