AAT3125
USB OTG 5V Charge Pump
General Description
The AAT3125 USB On-the-Go (OTG) charge pump
is a member of AnalogicTech's Total Power
Management IC™ (TPMIC™) product family. The
device integrates a high efficiency 1.5X fractional
100mA regulated charge pump for supplying V
BUS
with the additional functions required for OTG
devices (formerly known as dual role devices).
Four voltage detectors monitor V
BUS
, and a current
source dedicated for V
BUS
pulsing is provided for
compliance with Session Request Protocol (SRP)
as defined by the USB OTG Supplement.
The charge pump section uses a high efficiency
fractional topology, with a high frequency 750kHz
switching speed which enables the use of small
capacitors (less than 3.3µF). The AAT3125 fea-
tures extremely low quiescent current to extend
battery run time. Additionally, the device integrates
protection features such as under-voltage lockout,
and output short circuit and thermal protection.
The AAT3125 is available in a Pb-free, surface
mount QFN44-16 package and is rated over the
-40°C to +85°C temperature range.
Features
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ChargePump
™
V
IN
Range: 2.7V to 5.5V
Regulated Fractional Charge Pump
100mA Output Current
Reverse Load Protection
Power Good Flag
SRP Detection Flag
SRP Ready Flag
Output Short-Circuit and Thermal Protection
Under-Voltage Protection
Less than 1µA Consumed While Disabled
Designed to Allow Operation with Output
Capacitance as Low as 3.3µF
16-pin QFN44 Package
-40°C to +85°C Temperature Range
Applications
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•
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Cell Phones
Hand-Held Computers
PDAs
Typical Application
IN
OUT
1 Cell
Li-Ion
C
IN
1µF
AAT3125
C1+
C1-
OUTCP
R
CS
0.2Ω
80kΩ
VBUS
C
OUT
3.3µF to 6.5µF
C1
1µF
C2+
C2-
C
CP
1µF
R1
R2
R3
R4
C2
1µF
SR
EN
SR
EN
GND
POK1
POK2
SESDET
SRRDY
POK1
POK2
SESDET
SRRDY
3125.2005.12.1.4
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ANALOGICTECH [ ADVANCED ANALOGIC TECHNOLOGIES ]
