关于LDO的负载调整率单位

fd_alanYang · 发表于 2023-12-18 15:17:28

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LDO负载调整率有mV/mA，%/mA，ppm/mA，不太清楚他们之间的换算关系，请问这三种单位的负载调整率各自的计算公式是什么呢？

还有LDO线性调整率的ppm/V为单位的是什么公式求解出的呢？
提前谢过~

diabol · 发表于 2023-12-22 02:02:34

本帖最后由 diabol 于 2023-12-22 02:03 编辑

We use active loading to measure LDO load regulation performace.
The active loading will have the fixed current sinking and is independent of Vout.

mV/mA : (Vout measure at I2 - Vout measure at I1 ) / (I2-I1)
%/mA : (Vout measure at I1 / Vout no loading - 1 ) * 100% / (I1)
ppm/mA : (Vout measure at I1 / Vout no loading - 1 ) * 1e6 ppm / (I1)

The selection of I2,I1 loading is to keep LDO in linear region to have the best result.
Since in that region the small signal transfer function work properly.

LDO line regulation is based on : ( LDO PSRR+ ) and ( Referece Voltage PSRR+ * LDO feedback factor )

fd_alanYang · 发表于 2024-1-3 22:19:54

diabol 发表于 2023-12-22 02:02
We use active loading to measure LDO load regulation performace.
The active loading will have the f ...

thanks a lot!

w402370439 · 发表于 2024-1-3 22:36:40

mV/mA是绝对变化量，另外两个是根据输出典型值得相对变化量

dolamos · 发表于 2024-10-2 17:24:40

kan kan

Aliee · 发表于 2024-11-22 13:56:42

ppm是parts per million的缩写，“百万分之一”，量级是10的-6次方。所以ppm/V其实就是按照正常线性调整率的求解公式del VOUT/del VIN，然后单位取V，然后把结果数值乘以10的+6次方

[求助] 关于LDO的负载调整率单位

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