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AAT1189 Datasheet, PDF (10/19 Pages) Advanced Analogic Technologies – High Voltage Step-Down Regulator
Functional Block Diagram
DATA SHEET
AAT1189
High Voltage Step-Down Regulator
VINT
VL
Reg.
IN
OT
OSC
FB
COMP
EN
Error
Amp
CCoommpp..
Control
Logic
Voltage
Ref
Logic
20Ω
GND
Comp
VOCP
= 0.1V
BST
LX
RS
OS
Functional Description
The AAT1189 is a high voltage step-down (Buck) regula-
tor with input voltage range from 6.0V to 24.0V, provid-
ing high output current in a small package. The output
voltage is user-programmable from 1.5V to approxi-
mately 85% of VIN voltage. The device is optimized for
low-cost 12V adapter inputs.
The device utilizes voltage mode control configured for
optimum performance across the entire output voltage
and load range.
The controller includes integrated over-current, soft-
start and over-temperature protection. Over-current is
sensed through the output inductor DC winding resis-
tance (DCR). An external resistor and capacitor network
adjusts the current limit according to the DCR of the
inductor and the desired output current limit. Frequency
reduction limits the over-current stress during overload
and short-circuit events. The operating frequency returns
to the nominal setting when over-current conditions are
removed.
The AAT1189 is available in the Pb-free 16-pin TDFN34
package with rated operating temperature range of
-40°C to 85°C. The TDFN34-16's exposed paddle (EP)
can be soldered to the PCB plane(s) for maximum ther-
mal performance.
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com
10
202002A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • May 31, 2012