放大器THD怎么仿真

wz17735170416

想知道放大器的THD怎么仿真，输入信号的幅度为1m，频率为1kHz，这样仿真的时候应该如何设置？
另外，想要得到如下图这样的THD应当如何设置？

peterlin2010

spice sim FFt   .four

wz17735170416

peterlin2010 发表于 2022-12-21 22:23
spice sim FFt   .four

不好意思，这是什么意思能不能说的再详细点？不是太懂，谢谢

spartan313

放大器接成单位负反馈，激励给正弦波，然后跑tran, 测spectrum

peterlin2010

wz17735170416 发表于 2022-12-22 15:12
不好意思，这是什么意思能不能说的再详细点？不是太懂，谢谢

HSPICE hspice_integ.pdf


Measuring Full Spectrum (FFT) Analysis Results
With FFT as the selected as the Measure Analysis, the Special-Meas. tab is
enabled and selections can be made to measure: total harmonic distortion
(THD), signal to noise ratio (SNR), signal to noise-plus-distortion ratio (SNDR),
effective number of bits (ENOB), spurious free dynamic range (SFDR), and to
specify the harmonic up to which to carry out the measurement (nbharm).

For details on HSPICE measurement of FFT results see .MEASURE FFT in the
HSPICE Reference Manual: Commands and Control Options

When FFT is specified as the Measure Analysis, the UI controls are displayed
according to the following function settings:
1. THD is the default setting with the nbharm field empty. Optionally, set a
value for this harmonic (the default is the highest harmonic in the FFT
result).
2. If you select the function to be SNR, SNDR, or ENOB, the setup form is
updated as in Figure 144. Input values for nbharm, binsiz, and maxfreq,
as necessary.


Examples
Example 1 Measures frequency component at certain frequency.
.meas FFT v12 Find vm(1,2)at=20k
Example 2 Measures THD of a signal spectrum up to a specified harmonic.
.meas FFT thd56 THD V(node5, node6) nbharm=10
Example 3 Measures SNR/SNDR/ENOB of a signal up to a specified frequency.
.meas FFT snr12 SNDR V(node1, node2) maxfreq=1G
Example 4 Measures SFDR of a signal from minfreq to maxfreq and searching the
frequency component with maximum magnitude from minfreq to
maxfreq.
.meas FFT sfdr9 SFDR V(node9)
Example 5 Filters out the noise component within the bin.
.meas fft snrsrc SNR v(out) BINSIZ=10

zjouu

4楼的方式