We have question about TPS60403.
In datasheet p.17,
Two devices can be cascaded to produce an even larger negative voltage (see Figure 30). The unloaded output voltage is normally -2 × VI ,
but this is reduced slightly by the output resistance of the first device multiplied by the quiescent current of the second. When cascading more than two devices,
the output resistance rises dramatically.
We use this device in 3 series about cascaded.
you say that cascading more than two devices,the output resistance rises dramatically.
How is the resistance if we use cascading three devices?
If cascading device doubled or tripled, will output resistance doubled or tripled?
Impedance at 25℃ : 15Ω(max) (in datasheet p.5)
cascading 2 series : output resistance is 30Ω(15Ω x 2)
cascading 3 series : output resistance is 45Ω(15Ω x 3)
Is this understanding correct?
Do you have any formula?
Best regards,
Takahiro Nishizawa
