AAT2505 Analogic Corporation, AAT2505 Datasheet - Page 2

• Manufacturer Part Number: AAT2505
• Manufacturer: Analogic Corporation

Pin Descriptions
Pin Configuration
2
Pin #
EP
10
11
12
1
2
3
4
5
6
7
8
9
Symbol
ENLDO
PGND
SGND
VLDO
GND
VCC
OUT
POK
EN
LX
VP
FB
Step-down converter power ground return pin. Connect to the output and input capacitor
300mA LDO output pin. A 2.2µF or greater output low-ESR ceramic capacitor is required
Enable pin for LDO. When connected low, LDO is disabled and consumes less than 1µA
Step-down converter enable. When connected low, the step-down converter is disabled
Step-down converter signal ground. For external feedback, return the feedback resistive
Function
return. See section on PCB layout guidelines and evaluation board layout diagram.
Power switching node. Output switching node that connects to the output inductor.
Step-down converter power stage supply voltage. Must be closely decoupled to PGND.
Step-down converter bias supply. Connect to VP.
LDO input voltage; should be decoupled with 1µF or greater capacitor.
for stability.
Power-OK output for the LDO. This open drain output is low when the OUT is out of regu-
lation. Connect a pull-up resistor from POK to OUT or VLDO. When LDO is in shutdown
(ENLDO = 0V), POK is pulled low.
LDO ground connection pin.
of current.
and consumes less than 1µA.
Step-down converter feedback input pin. For fixed output voltage versions, this pin is con-
nected to the converter output, forcing the converter to regulate to the specific voltage.
For adjustable output versions, an external resistive divider ties to this point and programs
the output voltage to the desired value.
divider to this ground. For internal fixed version, tie to the point of load return. See sec-
tion on PCB layout guidelines and evaluation board layout diagram.
Exposed paddle (bottom). Use properly sized vias for thermal coupling to the ground
plane. See section on PCB layout guidelines.
PGND
VLDO
VCC
OUT
VP
LX
1
2
3
4
5
6
TDFN33-12
(Top View)
12
11
10
9
8
7
SGND
FB
EN
ENLDO
GND
POK
Converter/Linear Regulator
Dual Channel, Step-Down
2505.2006.06.1.1