What are voltages referred to in negative bias generator

[treez]

Hello,

I am using the LM7705 (charge pump) to provide a negative bias supply voltage for a previously single supply opamp ( i wish to get the Vout of the OPA335 opamp to go to zero).....however, i am trying to work out what the capacitor values are that i need to use.............



What do "V1" and "V2" on page 11 of the LM7705 datasheet refer to?

(my input supply voltage is 3.3V, and i my opamp is providing only 4mA maximum)

LM7705 datasheet
https://www.ti.com/lit/ds/symlink/lm7705.pdf

 

[chuckey]

"When the switch is in position A, capacitor CFLY will charge to voltage V1. The total charge on capacitor CFLY is
Q1 = CFLY x V 1. The switch then moves to position B, discharging CFLY to voltage V2. After this discharge, the
charge on CFLY will be Q2 = CFLY x V2. Note" - from half way up P.11
V1 = input voltage, V2 = transfer voltage
Frank