Help me fix a slow bandgap start-up in RC OSC

[lhlbluesky]

i have designed a RC osc circuit, and using a bandgap to generate the reference current and reference voltage of the osc, when simulating the bandgap only, the start up time is 1ms orso; but when i simulate the bandgap and osc together, the bandgap's start-up becomes very slow, about 10ms to settle, why? the loading is the same for the two case, what caused the slow start-up of bandgap? pls help me, thanks.

 

[dick_freebird]

Re: bandgap start-up question

Loading of what? The oscillator maybe loads one of the
bandgap nodes (likely the current ref), extending the natural
time constant vs the startup "boot current", maybe?

Buffer the interconnections appropriately with vcvs, and
see which one changes it back to "normal".