34704_11 Datasheet, PDF (47/54 Pages) Freescale Semiconductor, Inc – Multiple Channel DC-DC Power Management IC

FUNCTIONAL DEVICE OPERATION
COMPONENT CALCULATION
The passive components associated to these frequencies are calculated with the following formulas.
C1
=
-^V----ⁱ--ⁿ----^m----ⁱ-ⁿ--
V_RAMP
⎛
⎜
⎝
D^-----′^--_m^-1---_i^--_n^{--2-⎠⎟⎞}
⎛
⎝
2^----π^----(^--F^----_P^-1---_O^----R^----1^----)⎠⎞
C2
=
⎛
⎝
-₂---_π----₍--_F----¹_Z---₂---_R-----₁----_{)⎠⎞}
R2
=
⎛
⎝
2^----π^----(^--F^----1_Z^---₁^---C^-----1^----)⎠⎞
R3
=
⎛
⎝
-₂---_π----₍--_F----¹_P----₁---_C----₂----_{)⎠⎞}
C3
=
⎛
⎝
2^----π^----(^--F^----1_P^----₂^---R^----2^----)⎠⎞
On the 34704 V_RAMP is half of 1.2 V since each operation mode spends only half the ramp.
Analog Integrated Circuit Device Data
Freescale Semiconductor
34704
47