AAT3125ISN-T1 Analogic Tech, AAT3125ISN-T1 Datasheet - Page 9

• Manufacturer Part Number: AAT3125ISN-T1
• Description: Switching Converters, Regulators & Controllers USB OTG 5V Charge Pump
• Manufacturer: Analogic Tech

Specifications of AAT3125ISN-T1

• Output Voltage: 6 V (Max)
• Output Current: 100 mA
• Input Voltage: 2.9 V
• Switching Frequency: 750 KHz
• Operating Temperature Range: - 40 C to + 85 C
• Mounting Style: SMD/SMT
• Package / Case: QFN44-16
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

Functional Block Diagram
Functional Description
Charge Pump
The AAT3125 charge pump uses a 1.5X topology;
the two flying capacitors are charged in series and
discharged in parallel. Using this topology, output
current is approximately 2/3 input current. Since
the power bus in battery-operated devices that use
a single cell lithium-ion/polymer battery ranges
from 3V to 4.5V, an output voltage above 4.4V can
be maintained. Output voltage is regulated to 5V
and output current is limited by the value of R
The charge pump is designed to operate safely
with any combination of input and output voltages.
Current is not allowed to flow from OUT to IN.
10mA Current Source
A 10mA current source supplies current to OUT for
V
length of time needed to charge capacitance con-
nected to OUT distinguishes between non-SRP
capable devices and SRP capable devices. Using
3125.2005.12.1.4
BUS
pulsing during SRP. During V
SR
EN
IN
Reference
Control
Voltage
UVLO
OTMP
BUS
pulsing, the
C1+ C1- C2+ C2-
5V Charge Pump
CS
10mA
.
10mA, SESDET should rise about 7ms after
SRRDY rises when an OTG device is connected.
With a non-OTG device connected, this period is at
least 70ms. 10mA should not damage non-SRP
capable hosts that allow reverse current flow from
the bus. Current is not allowed to flow from OUT
to IN through the current source.
SESDET MicroPower Voltage Detector
The SESDET open drain output signals the use of
SRP while the system is acting as the A device.
OUT powers this detector because the local 5V
bus may not be powered when the B device initi-
ates SRP.
150µA to OUT, the detector consumes only 7µA.
SRRDY Voltage Detector
The SRRDY open drain output signals that V
ready for SRP. SRRDY is powered by IN and is
active as long as IN is above the UVLO level.
SRRDY is true (low) when OUT is below the
SRRDY threshold (0.6V nominal). SRRDY is false
GND
OC
4.0
4.4
2.0
0.6
USB OTG 5V Charge Pump
Since V
OUTCP
OUT
POK1
POK2
SESDET
SRRDY
BUS
provides no more than
AAT3125
BUS
is
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