Bat boost

how does volume changed with L and Isat

Toroid inductance Core Material

• R increases with N, but L increase with N^2
• L increases with A, eg A~radius^2, but Res ~ radius
• assume saturation depends on B (eg Bmax), thus there is a Imax limit
• But increasing A, increases L at A^2, but R linearly. Volume increases ~linearly w/A

multiphase

http://powerelectronics.com/power_management/regulator_ics/multiphase-converter-ic-power-requirements-0101/

efficiency

[1]

split pi

http://en.wikipedia.org/wiki/Split-pi

old

• Assume 9V is Vbat min (probably less due to ESR).
• Also assuming peak L charge time is 1uS
• Single phase requires 70 amps
• Lmax = 9/70 = 0.13uH
• 2 phase, Lmax = 9/35 = 0.26uH
• 4 phase, Lmax = 0.514uH (Imax=17.4)