AAT1153 Datasheet, PDF (18/19 Pages) Advanced Analogic Technologies – 2A Step-Down Converter

Input Capacitor
Input ripple V_PP = 25mV
1
1
C_IN(MIN) = _{⎛ VPP}
⎝ I_O
- ESR^⎞⎠ · 4 · f_S
=
= 13.9µF; use 22µF
⎛0.025
⎝2
-
0.01^⎞⎠
·4
· 1.2
· 10⁶
I_RMS =
I_O
2
=
2
2
= 1Arms
P_CIN = ESR · I_RMS2 = 0.01 · 1² = 10mW
DATA SHEET
AAT1153
2A Step-Down Converter
AAT1153 Losses
P_TOTAL = I_O2 · R_DS(ON)P · D + I_O2 · R_DS(ON)N · (1 - D) + (tSW · f_S · I_O) · V_IN
1.8
= 2² · 0.135 ·
4.2
+ 2² · 0.095 · ^⎛⎝1 -
1.8_⎞
4.2⎠
+
(5
·
10^-9
·
1.2
·
10⁶
·
2)
·
4.2
=
498.9mW
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18
201992B • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • March 18, 2013