AAT4685 Datasheet, PDF (1/17 Pages) Skyworks Solutions Inc. – thermal shutdown protection

DATA SHEET
AAT4685
Over-Voltage Protection Switch with OCP and BOVP
General Description
The AAT4685 OVPSwitch™ is a member of Skyworks'
Application Specific Power MOSFET™ (ASPM™) product
family. It is an N-channel MOSFET power switch with
precise over-voltage protection control, designed to pro-
tect low-voltage systems against high-voltage faults up
to +28V. It also integrates over-current protection
(OCP), battery over-voltage protection (BOVP) and over-
temperature protection (OTP).
When the input voltage exceeds the programmed over-
voltage threshold, the N-channel MOSFET switch will be
turned off to prevent damage to the output load circuits.
An external resistor divider is adopted to program the
adjustable version over-voltage trip point. Over-current
protection protects the case of output short circuits by
disconnecting the load from the input supply.
A battery voltage monitor is integrated and disconnect
the IN and OUT when the battery voltage exceed its rated
voltage. The AAT4685 also monitors its own die tempera-
ture and OVP switch off if it becomes too hot.
The AAT4685 includes an under-voltage lockout (UVLO)
protection circuit, which puts the device into sleep mode
at low input voltages only consuming 100μA current. It
also includes two indicators: input supply power good
indicator (POK) which is always active whether EN is low
or high, and a fault flag indicator (FLT) which goes to
active low when a fault condition (OV, OC, BOV and OT)
occurs at EN = low.
The AAT4685 is offered in a Pb-free, 3x3mm 12-pin
TDFN package with a pin-out optimized for safety and is
specified for operation over the -40°C to +85°C ambient
temperature range.
Features
• V_IN Range: 3.0V – 28V
• OVP Threshold Setting Range: 4V – 7V
▪ Fixed: 5.85V and 6.8V
▪ Adjustable
• Fast OVP Response:
1μs (max) Response to Over-Voltage Transient
• OVP Recovery Delay Time: 8ms
• Over-Current Protection
• Adjustable 0.3 – 1.8A
• Battery OVP 4.35V
• Thermal Shutdown Protection
• Low Quiescent Current
▪ ^{600μA Typical}
▪ 100μA Typical Standby Current
• Under-Voltage Lockout
• 120mΩ Typical R_{DS(ON) at 5.0V}
• Active Low Enable with Internal 200kΩ Pull-Down
Resistor
• Input Supply Power Good Indicator, Open Drain
• OVP/OCP/BOVP/OT Fault Indicator, Open Drain
• Temperature Range: -40°C to 85°C
• 3x3mm TDFN-12 Package
Applications
•Cell Phones
•Digital Still Cameras
•MP3
•Personal Data Assistants (PDAs)
Typical Application
V_IN 3.0V – 28V
R_OVP1
C1
1μF
R_OVP2
R_OCP
IN
OUT
AAT4685 _FLT
OVP
OCP
IC _{EN GND}
POK
BOVP
C2
1μF
V_OUT
Fault Flag
BAT
V_IO V_IO
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [e-mail] • www.skyworksinc.com
201960A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • May 16, 2012
1