AAT1185 Datasheet, PDF (2/16 Pages) Skyworks Solutions Inc. – High Voltage Step-Down Controller

DATA SHEET
AAT1185
High Voltage Step-Down Controller
Pin Descriptions
Pin #
1
2
3
4
5
6
7
8
9, 11
10
12
13
14
Symbol
RS
OS
EN
BST
DH
LX
PGND
DL
VL
IN
GND
FB
COMP
Function
I
I
I
I
O
O
GND
O
I/O
I
GND
I
I
Description
Output sense voltage pin. Connect to the output capacitor to enable over-current
sense for step-down converter.
Output current sense pin. Connect a small signal resistor from this pin to small signal
resistor which is tied to switching node (LX) to enable over-current sense for step-
down converter. The current limit threshold varies with inductor parasitic winding re-
sistance (R_DC(L)); see the Applications Information section of this datasheet for details.
Step-down regulator enable input pin. Active high or tied to high voltage input (IN)
enables internal linear regulator and output.
Step-down regulator boost drive input pin. Connect the cathode of fast rectifier from
this pin and connect a 100nF capacitor from this pin to the switching node (LX) to
provide drive to external hi-side MOSFET gate.
High side driver for external high side n-channel MOSFET. Connect this pin to gate of
external high side n-channel MOSFET device.
Step-down converter switching pin. Connect output inductor to this pin.
Power ground pin for step-down regulator. When using synchronous option, tie to PCB
ground plane near source pins of external low-side MOSFET(s).
Low side driver for external low side n-channel MOSFET. When using synchronous op-
tion, connect this pin to gate of external low side n-channel MOSFET device. Other-
wise, leave pin open.
Internal linear regulator for step-down converter. Connect a 2.2μF/6.3V capacitor from
this pin to GND.
High voltage input pin.
Ground pin for step-down regulator. Tie to PCB ground plane.
Feedback input pin for step-down converter. Connect an external resistor divider to
this pin to program the output voltage to the desired value.
Compensation pin for step-down converter. Connect a resistor, capacitor network to
compensate the voltage mode control loop.
Pin Configuration
TSOPJW-14
(Top View)
RS ¹
OS ²
EN ³
BST ⁴
DH ⁵
LX ⁶
PGND ⁷
14 _COMP
13 _FB
12 _GND
11 _VL
10 _IN
9 _VL
8 _DL
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [e-mail] • www.skyworksinc.com
2
202001A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • May 31, 2012