Testing a Start-up Circuit

[bsshwetha]

Hi,

Could someone please tell me how I can simulate a startup circuit? It is a part of a Bandgap Ref. Circuit, that i need to test.

Thanks and Regards

 

[pfd001]

add ramp signal at the VDD, then run a transient simulation, you can test the start up circuits

 

[jerryzhao]

give Power supply (VDD) from 0 to VDD voltage about 1ms for simulation.
Test: add a large capacitor between vdd and gnd, then supply power and test.

 

[sriramachandra]

Add some load and ramp up the input supply.
DOnt forget to add capacitance .... preferably more than what ur circuit offers

 

[acidwabbit]

What you are doing now is probably right

 

[jeffsky520]

Hi, you can simulate your startup circuit by two methods:
1, supply power ramps up slowly
2, power down and power up again.

 

[finalvolition]

About the method by ramp up supply, it is not exactly confirmed if the circuit can work. It is because the node is unknow when power ramp up. The method to ensure if it works is to keep supply constant(VDD) as well as set initial conition at critical point to have zero initial current.

 

[srieda]

About the method by ramp up supply, it is not exactly confirmed if the circuit can work. It is because the node is unknow when power ramp up. The method to ensure if it works is to keep supply constant(VDD) as well as set initial conition at critical point to have zero initial current.

If the power supply is zero, i cant understand how there could be any current!!

 

[Alex_IC]

You can find the info in Kundert's book in the chapter 2.4.1 Circuits with Multiple Operating Points. The Designer's Guide to Spice&Spectre (Kluwer Academic Publishers).