AAT4685 Datasheet, PDF (14/17 Pages) Skyworks Solutions Inc. – thermal shutdown protection

DATA SHEET
AAT4685
Over-Voltage Protection Switch with OCP and BOVP
Output Capacitor
In order to insure stability while current limit is active, a
small output capacitance of approximately 1μF is required
at the output. Likewise, with the output capacitor, there
is no specific capacitor ESR requirement. If desired, C_OUT
may be increased to accommodate any load transient
condition.
PCB Layout Recommendations
For proper thermal management and to take advantage
of the low R_{DS (ON)} of the AAT4685, certain circuit board
layout rules should be followed:
1. V_IN and V_OUT should be routed using wider than nor-
mal traces.
2. GND should be connected to a ground plane. The
ground plane area connected to the ground pins
should be made as large as possible. Exposed pad
should be connected to ground plane to get best
power dissipation.
3. For best performance, C_IN and C_OUT should be placed
close to the IN and OUT pins.
Evaluation Board Schematic
+5V
VIN
12
+5V
Disable
R1
604k
C1 R2
1μF 100k
R3
30k
U1
AAT4685
7
IN
8
IN
12 _OVP
1 _OCP
3
EN
2
IC
OUT
OUT
BOVP
POK
FLT
GND
Red LED
R5
1.74k
6
5
11
4
10
9
C2
1μF
Green LED
R6
1.74k
VOUT
R4
100k
BATT
Figure 1: AAT4685 Evaluation Board Schematic.
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [e-mail] • www.skyworksinc.com
14
201960A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • May 16, 2012