40 lines
1.2 KiB
Markdown
40 lines
1.2 KiB
Markdown
---
|
||
title: VGA
|
||
updated: 2022-01-12 02:49:03Z
|
||
created: 2022-01-08 14:06:18Z
|
||
latitude: 1.29820000
|
||
longitude: 103.78360000
|
||
altitude: 0.0000
|
||
---
|
||
|
||
# MAAM-011100
|
||
|
||
Broadband Variable Gain Amplifier (VGA) 400MHz-20GHz
|
||
|
||
75RBM
|
||
|
||
调谐电压[0,-2]V，MCU的DAC输出电压(0,3.3)，考虑到误差，达不到极限0，3.3V
|
||
优化后传输函数为==y=-1.5x+2.5==，2.5V电压是采用TL431作为基准，电路图为 -2V-CTL-driver.png
|
||
|
||
实际输出映射关系
|
||
|MCU| CTL|
|
||
|:-:|:-:|
|
||
1.6 |0.1
|
||
3.1 |-2.15
|
||
tps61040产生±5V电压，供给运放和VGA的偏置
|
||
|
||
|
||
20200611更新
|
||
改为同向驱动，即输入输出同大同小，电压越高增益越大
|
||
则传输函数为==y=x-2.5==，电路图为-2v-driver-new.png
|
||
|
||
实际输出映射关系
|
||
|MCU|CTL|
|
||
|:-:|:-:|
|
||
0.6|-2.1
|
||
2.6 |0.1
|
||
运放需要支持双电源，可选用M2107G-AF5-R 够用、体积小，便宜
|
||
调谐灵敏度约为15.5dB/V，参考来源：gain-VC.png
|
||
|
||
|