AAT2687 Datasheet, PDF (2/20 Pages) Advanced Analogic Technologies – PMIC Solution for 24V Systems with 2 High Performance Step-Down Converters

DATA SHEET
AAT2687
Pin Descriptions
PMIC Solution for 24V Systems
with 2 High Performance Step-Down Converters
Pin #
1
2
3, 4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
EP
Symbol
LX1
LX1
N/C
BST1
EN1
GND2
EN2
N/C
IN2
OUT2
N/C
RS1
OS1
COMP1
FB1
GND1
VL1
VL1
N/C
N/C
IN1
LX1
LX1
EP
Function
Channel 1 step-down converter switching pin. Connect output inductor to this pin. Connect all four LX1 pins
together.
Channel 1 step-down converter switching pin. Connect output inductor to this pin. Connect all four LX1 pins
together.
No Connect. Can be used to route IN1 and EP.
Channel 1 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 channel 1 switching node (LX1) for internal high-side MOSFET
gate drive.
Channel 1 step-down regulator enable input pin. Active high enables the channel 1 output. It can be tied to VIN1.
Ground pin for Channel 2. Power return pin for channel 2. Connect return of channel 2 input and output ca-
pacitors close to this pin for best noise performance.
Channel 2 linear low dropout (LDO) enable input pin. Active high enables the channel 2 output. It can be tied
to VOUT1.
No Connect. Can be used to route IN2.
Input supply voltage pin for channel 2 linear low dropout (LDO) regulator. Connect 2.2μF ceramic input ca-
pacitor close to this pin.
Output of channel 2 of linear low dropout (LDO) regulator. Connect a 2.2μF ceramic capacitor from this pin to
GND pin.
No Connect. Can be used to route OUT2.
Channel 1 output current sense pin. Connect a small signal resistor from this pin to channel 1 switching node
(LX) to enable over-current sense for step-down converter.
Channel 1 output sense voltage pin. Connect to the output capacitor to enable over-current sense for step-
down converter.
Compensation pin for channel 1 step-down regulator. Connect a series resistor, capacitor network to compen-
sate the voltage mode control loop.
Feedback input pin for channel 1 step-down converter. Connect an external resistor divider to this pin to pro-
gram the output voltage to the desired value.
Ground pin for Channel 1. Power return pin for channel 1. Connect return of channel 1 input and output ca-
pacitors close to this pin for best noise performance.
Internal linear regulator for channel 1 step-down converter. Connect a 2.2μF/6.3V capacitor from this pin to
GND1 pin.
Internal linear regulator for channel 1 step-down converter. Connect to pin 18.
No Connect. Do not connect to any node on the PCB.
No Connect. Can be connected to GND.
Input supply voltage pin for channel 1 step-down regulator. Connect both IN1 pins together. Connect the input
capacitor close to this pin for best noise performance.
Channel 1 step-down converter switching pin. Connect output inductor to this pin. Connect all four LX1 pins
together.
Channel 1 step-down converter switching pin. Connect output inductor to this pin. Connect all four LX1 pins
together.
Exposed paddle tied to IN1. Connect to PCB heatsink for optimum thermal performance of internal LDO device.
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202033A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • June 8, 2012