Inverting converter - CCM operation:
***Allow 30 secs for the circuit to reach steady state***
The inverting buck-boost converter is capable of creating an output voltage that is either higher or lower than the input voltage. Another characteristic is that the output voltage is of negative sign. Note the current flow direction through the load resistance.
In CCM where the inductor current is continuous we have:
ON time --> IL = D*Ts*Vi/L
OFF time --> IL = (1-D)*Ts*Vo/L
Equating the volt-seconds on the inductor we have that the voltage conversion formula is:
Vo = - Vi*D/(1-D), where D is duty cycle.
For further info and to see design formulas with component selection steps visit the blog page at:
http://j.gs/5535160/buck-boost-formulas