sheldon
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Uncle Ezra,
What is the supply voltage for the LDO? If the pnp does not have enough headroom, then the beta may have strange values. I did some simulations and the drop-out voltage is about 0.7 for the transistor, see the attached plots. BTW, the simulations are for a 1.8V LDO with 100mA of load current and show the power supply being swept from 2.25V to 3V. The LDO does not start acting like an LDO until the dropout voltage is greater than about 2.5V.
Also, my previous remark about it was incorrect. The IS of the transistor is fine so the scaling should be correct. The low ISE just means that the process is clean and the transistor has good low current beta.
Best Regards,
Sheldon
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