AAT3129_07 ANALOGICTECH [Advanced Analogic Technologies], AAT3129_07 Datasheet - Page 9

• Manufacturer Part Number: AAT3129_07
• Description: High Efficiency 1X/1.5X/2X Charge Pump for RGB Color LED Applications
• Manufacturer: ANALOGICTECH [Advanced Analogic Technologies]

Functional Block Diagram
Functional Description
The AAT3129 is a tri-mode load switch (1X) and
high efficiency (1.5X or 2X) charge pump device
intended for fashion color LED lighting applications.
To maximize power conversion efficiency, an inter-
nal sensing circuit monitors the voltage required on
the constant current source output and sets the
load switch and charge pump modes based on the
input battery voltage and the current source output
voltage. As the battery discharges over time, the
AAT3129 charge pump is enabled when the current
source output nears dropout. The charge pump ini-
tially starts in 1.5X mode. If the charge pump out-
put drops enough for the current source output to
3129.2007.01.1.4
EN/SET
AS
Interface
2
Cwire
High Efficiency 1X/1.5X/2X Charge Pump
Reference
Soft Start
Oscillator
Voltage
Control
1MHz
become close to dropout, the charge pump will
automatically transition to 2X mode.
The AAT3129 requires only four external compo-
nents: two 1μF ceramic capacitors for the charge
pump flying capacitors (C1 and C2), one 1μF
ceramic input capacitor (C
1μF ceramic output capacitor (C
The color and brightness of an RGB color LED is
maintained by PWM signals, which are pro-
grammed via the AS
block generates three gate drive PWM signals for
the N-channel MOSFET switches. Please refer to
the interface description and timing in the following
section for details.
for RGB Color LED Applications
Charge
Pump
1.5X
VIN
1X
2X
GND
2
Cwire interface. The control
IN
ISRC
DR
DG
DB
C1+
C1-
C2+
C2-
CP
), and one 0.33μF to
P
).
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