AAT3131 View Datasheet(PDF) - Advanced Analogic Technologies
Part Name
Description
MFG CO.
AAT3131
Advanced Analogic Technologies
'AAT3131' PDF : 14 Pages View PDF
AAT3131
High Efficiency 1X/1.5X Fractional
Charge Pump for White LED Applications
General Description
The AAT3131 is a low noise, constant frequency
charge pump DC/DC converter that uses a dual
mode Load Switch (1X) and fractional (1.5X) con-
version to maximize efficiency for White LED appli-
cations. The device can be used to produce cur-
rent levels up to 20mA in three of its outputs, and
30mA in one of its outputs to drive LEDs from a
2.7V to 5.5V input. Outputs may be operated indi-
vidually or paralleled for driving higher-current
LEDs. Low external parts counts (two 1µF flying
capacitors and two small 1µF capacitors at VIN,
and OUT) make the AAT3131 ideally suited for
small battery-powered applications.
AnalogicTech™'s Simple Serial Control™
(S2Cwire™) interface is used to enable, disable
and set the LED drive current in two groups: the
three 20mA outputs and the single 30mA output
with multiple level logarithmic scales. The AAT3131
has a thermal management system to protect the
device in the event of a short circuit condition at the
output pin. Built-in soft-start circuitry prevents
excessive inrush current during start-up. A high
charge pump switching frequency enables the use
of very small external capacitors. A low current
shutdown feature disconnects the load from VIN
and reduces quiescent current to less than 1µA.
The AAT3131 is available in very small 12 pin
TSOPJW12 package.
Typical Application
Features
ChargePump™
• VIN Range: 2.7 - 5.5 Volts
• < 1.0µA of Shutdown current
• 1.0 MHz Switching Frequency
• White LED Backlighting
• Fully Independent Display Lighting
• Dual Mode 1x and 1.5x Charge Pump for
Maximum Efficiency
• Drives Low-VF & High-VF f Type LED's
• Up to three 20mA Outputs
• Single 30 mA Output
• Multi Position Logarithmic Scale with Digital
Control
• Low Noise Constant Frequency Operation
• Regulated Output Current
• Automatic Soft-Start
• No Inductors
• -40 to +85°C Temperature Range
• 12 pin TSOPJW-12 package
Applications
• White LED Backlighting
• White Photo-Flash for DSC's
• Color (RGB) Lighting
• Programmable Current Source
VBATTERY
CIN
COUT
1µF
1µF
EN/SET
VIN
C1+
VOUT
C1-
C2+
AAT3131
C2-
D1
D2
D3
D4
EN/SET
GND
C1
1µF
C2
1µF
D5
D4
D3
D2
D1
3131.2004.08.1.1
1
Share Link: 