模型考虑到了采样开关RC延时以及，沟道电荷泄露的非理想因素

采样保持电路

原代码：

// VerilogA for SampleAndHold
`include "constants.vams"
`include "disciplines.vams"
module VerilogA_SampleAndHold(clk,vin,vmin,vout);
parameter real vtrans=0.5;
parameter real delay = 0;
parameter real ttime = 1p;
parameter real clk_threshold = 0.5; //vdd is 1v
input clk,vin,vmin;
output vout;
electrical vout,vin,vmin,clk;
real v;
analog begin
// Sampling Phase (+1 is for rising edge, -1 is for falling edge)
    @(cross(V(clk) - clk_threshold, +1))
        v = V(vin);
    V(vout) <+ transition(v,delay,ttime);
end
endmodule

非理想因素：由于导通电阻和保持电容充放电RC延时

修改参数ttime，改变跟随斜率

原代码存在只跟随脉冲上升沿数值，没有模拟沟道电荷注入效应影响

改进了VerilogA代码，使其支持模拟沟道电荷注入效应

// VerilogA for SampleAndHold



`include "constants.vams"

`include "disciplines.vams"



module VerilogA_SampleAndHold(clk,vin,vmin,vout);



parameter real vtrans=0.5;

parameter real delay = 0;

parameter real ttime = 0.2n;

parameter real clk_threshold = 0.5; //vdd is 1v

parameter real charge_injection_value = 0.01;



input clk,vin,vmin;

output vout;



electrical vout,vin,vmin,clk;



real v;

real T_time;

analog begin



if (V(clk) - clk_threshold > 0 ) begin

v = V(vin);

T_time = ttime;

end



@(cross(V(clk) - clk_threshold, -1))

begin

v = V(vout) - charge_injection_value;

T_time = ttime/100;

end

V(vout) <+ transition(v,delay,T_time);

end

endmodule

参数charge_injection_value即为沟道电荷注入效应的影响

改进后仿真结果如下

对采样结果频谱分析

Fin = 2,734,375Hz Fs = 200MHz DFT采样点数512