Simulation result difference between LT1009 LTSpice and QSpice Model

Hi all,

It seems that there is a problem when I try to convert LT1009 reference voltage from LTSpice model to QSpice. The LT1009 is a 2.5V voltage reference. I havec extract this model from the LTC3.lib LTSpice library to implement it with QSpice.
The problem is, that with same schematic expected result is not identical; LTSpice returns 2.50V@25°C when QSpice gives 2.12V@25°C.
LtSpice and QSpice simulation results below:

RH1009.qsym (1.2 KB)

I need your help.

The temperature for the 2.12V in Qspice is also diferente, isn’t it?

No, he reads at the same temperature in both

Different spice simulators define capacitor model differently.
Qspice and LTspice both have Rpar and Rser, but treat Rpar and Rser differently.

C1 and C2 in LT1009 subckt have Rpar and Rser, which is major reason of different result between Qspice and LTspice

Here is modified .subckt based on above method
LT1009_Qspice.txt (445 Bytes)
LT1009.qsym (1.1 KB)
(may still have other factors contribute after modify, but not that important)

compare with LTspice


@Poupy you may be the first post click on “solution” after this feature added into forum. :rofl:

1 Like