AAT2749 Datasheet, PDF (16/17 Pages) Skyworks Solutions Inc. – 3.0MHz Step-Down Converter and Low-V in LDO

DATA SHEET
AAT2749
3.0MHz Step-Down Converter and Low-V_IN LDO
AAT2749 Losses
All values assume 25°C ambient temperature and thermal resistance of 284°C/W in the CSP-9 package.
P_TOTAL
=
I_OUT12
·
(R_DS(ON)H
·
V_OUT1 +
V_IN1
R_DS(ON)L
·
[V_IN1
-
V_OUT1])
+ (t_SW · F_S · I_OUT1 + I_Q1) · V_IN + (V_IN2 - V_OUT2) · I_OUT2
600mA² · (360mΩ · 1.8V + 200mΩ · [5V - 1.8V])
=
5V
+ (5ns · 3MHz · 600mA + 100μA) · 5V + (1.8V - 1.2V) · 300mA
P_TOTAL = 318mW
T_J(MAX) = T_AMB + Θ_JA · P_LOSS = 25°C + (284°C/W) · 318mW = 115°C
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [e-mail] • www.skyworksinc.com
16
202037A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • June 8, 2012