AAT3157 Pump Datasheet

AAT3157 Datasheet PDF, Equivalent


Part Number

AAT3157

Description

High Efficiency 1X/1.5X/2X Charge Pump

Manufacture

AAT

Total Page 11 Pages
PDF Download
Download AAT3157 Datasheet PDF


AAT3157
www.DataSheet4U.com
AAT3157
High Efficiency 1X/1.5X/2X Charge Pump
For White LED Applications
General Description
Features
ChargePump
The AAT3157 is a low noise, constant frequency
charge pump DC/DC converter that uses a tri-
mode load switch (1X), fractional (1.5X), and dou-
bling (2X) conversion to maximize efficiency for
white LED applications. The AAT3157 is capable of
driving up to three channels of LEDs at 20mA per
channel from a 2.7V to 5.5V input. The current
sinks may be operated individually or in parallel for
driving higher current LEDs. A low external parts
count (two 1μF flying capacitors and two small 1μF
capacitors at IN and OUTCP) make this part ideal-
ly suited for small, battery-powered applications.
AnalogicTech's S2Cwire(Simple Serial Control)
serial digital input is used to enable, disable, and set
current for each LED with 16 settings down to 50μA.
The low-current mode supply current can be as low
as 50μA to save power.
Each output of the AAT3157 is equipped with built-
in protection for output short-circuit and auto-dis-
able for load short-circuit conditions. Built-in soft-
start circuitry prevents excessive inrush current
during start-up. A low-current shutdown feature dis-
connects the load from the input and reduces qui-
escent current to less than 1μA.
The AAT3157 is available in a Pb-free, space-sav-
ing 2.85x3.0mm 12-pin TSOPJW package.
• VIN Range: 2.7V to 5.5V
• Fully Programmable Current with Single Wire
— 16 Current Levels
— Four Low Current Settings Down to 50µA
• Low IQ (50µA) for Low Current Mode
• Tri-Mode 1X, 1.5X, and 2X Charge Pump for
Maximum Efficiency and VF Coverage
• Drives up to Three Channels of LEDs
• No Inductors, Low Noise Operation
• 1MHz Constant Switching Frequency
• Small Application Circuit
• Built-In Thermal Protection
• Automatic Soft Start
• IQ <1µA in Shutdown
• 2.85x3.0mm TSOPJW-12 Package
Applications
• Color (RGB) Lighting
• Programmable Current Sinks
• White LED Backlighting
• White Photo Flash for Digital Still Cameras
Typical Application
C1
1µF
2.7V to 5.5V
CIN
1µF
EN/SET
C1+ C2+
C1- C2-
IN OUTCP
AAT3157
GND
EN/SET
D1
D2
D3
C2
1µF
D1 D2 D3
COUT
1µF
3157.2006.05.1.2
1

AAT3157
www.DataSheet4U.com
AAT3157
High Efficiency 1X/1.5X/2X Charge Pump
For White LED Applications
Pin Descriptions
Pin #
1
2
3
4
5
6
7
8
9
10
11
12
Symbol
D3
D2
D1
GND
IN
C2-
C2+
OUTCP
C1-
C1+
EN/SET
N/C
Function
Current sink input #3.
Current sink input #2.
Current sink input #1.
Ground.
Input power supply. Requires 1µF capacitor connected between this pin and
ground.
Flying capacitor 2 negative terminal.
Flying capacitor 2 positive terminal. Connect a 1µF capacitor between C2+ and
C2-.
Charge pump output to drive load circuit. Requires 1µF capacitor connected
between this pin and ground.
Flying capacitor 1 negative terminal.
Flying capacitor 1 positive terminal. Connect a 1µF capacitor between C1+ and
C1-.
S2Cwire serial interface control pin.
No connection.
Pin Configuration
TSOPJW-12
(Top View)
D3
D2
D1
GND
IN
C2-
1
2
3
4
5
6
12 N/C
11 EN/SET
10 C1+
9 C1-
8 OUTCP
7 C2+
2 3157.2006.05.1.2


Features www.DataSheet4U.com High Efficiency 1X/ 1.5X/2X Charge Pump For White LED Appli cations General Description The AAT3157 is a low noise, constant frequency cha rge pump DC/DC converter that uses a tr imode load switch (1X), fractional (1.5 X), and doubling (2X) conversion to max imize efficiency for white LED applicat ions. The AAT3157 is capable of driving up to three channels of LEDs at 20mA p er channel from a 2.7V to 5.5V input. T he current sinks may be operated indivi dually or in parallel for driving highe r current LEDs. A low external parts co unt (two 1μF flying capacitors and two small 1μF capacitors at IN and OUTCP) make this part ideally suited for smal l, battery-powered applications. Analog icTech's S2Cwire™ (Simple Serial Cont rol™) serial digital input is used to enable, disable, and set current for e ach LED with 16 settings down to 50μA. The low-current mode supply current ca n be as low as 50μA to save power. Eac h output of the AAT3157 is equipped with builtin protection for output .
Keywords AAT3157, datasheet, pdf, AAT, High, Efficiency, 1X/1.5X/2X, Charge, Pump, AT3157, T3157, 3157, AAT315, AAT31, AAT3, Equivalent, stock, pinout, distributor, price, schematic, inventory, databook, Electronic, Components, Parameters, parts, cross reference, chip, Semiconductor, circuit, Electric, manual, substitute




@ 2014 :: Datasheetspdf.com :: Semiconductors datasheet search & download site (Privacy Policy & Contact)