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High Efficiency 1.5X Fractional Charge Pumps For White LED Applications General Description
The AAT3113 and AAT3114/14A are low noise, constant frequency charge pump DC/DC converters that use fractional (1.5X) conversion to increase efficiency in white LED applications. The devices can be used to produce current levels up to 20mA for each output from a 2.7V to 5.5V input. A low external parts count (two 1µF flying capacitors and two small bypass capacitors at VIN and OUT) makes these devices ideally suited for small, battery-powered applications.
AAT3113, AAT3114/14A
ChargePump™
Features
• • • • • • • • • • • • • • • • •
AnalogicTech’s Simple Serial Control™ (S2Cwire™) interface is used to enable, disable, and set the LED drive current for 32-level logarithmic scale LED brightness control. AAT3113 and AAT3114/14A devices have a thermal management system for protection in the event of a short-circuit condition on any of the output pins. Built-in soft-start circuitry prevents excessive inrush current during start-up. A high switching frequency enables the use of small external capacitors. A low-current shutdown feature disconnects the load from VIN and reduces quieswww.DataSheet4U.com cent current to less than 1µA. The AAT3113 provides four LED current source outputs, and the Applications AAT3114/14A provides six. The AAT3113 is available in a Pb-free 12-pin TSOPJW package, and the • Programmable Current Source AAT3114/14A is available in a Pb-free 16-pin QFN • White LED Backlighting package.
AAT3113: Four Outputs AAT3114/14A: Six Outputs 20mA Full-Scale Current Simple Serial Control (S2Cwire) Interface — 32-Position Logarithmic Scale with Digital Control Low Noise Constant Frequency Operation 33% Less Input Current Than Doubler Charge Pump High Accuracy Brightness Matching Small Application Circuit Regulated Output Current Automatic Soft Start VIN Range: 2.7V to 5.5V No Inductors 600kHz Switching Frequency IQ <1µA in Shutdown Temperature Range: -40°C to 85°C 12-Pin TSOPJW Package (AAT3113) 16-Pin QFN Package (AAT3114/14A)
Typical Application
VIN C1+ C1 1μF OUT VBATTERY CIN 1μF COUT 1μF C1C2+ C2 1μF
AAT3114/14A
C2D1 D2 D3 D4 D5 D6
EN/SET
EN/SET GND
D6
D5
D4
D3
D2
D1
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High Efficiency 1.5X Fractional Charge Pumps For White LED Applications Pin Descriptions
Part #
AAT3114/14A AAT3113
AAT3113, AAT3114/14A
Symbol
D2 D3 D4 D5 D6 C1+ C1NC OUT C2+ C2GND NC VIN EN/SET D1
Function
Current source output 2. Current source output 3. Current source output 4. Current source output 5 (AAT3114/14A option only). Current source output 6 (AAT3114/14A option only). Flying capacitor 1 positive terminal. Flying capacitor 1 negative terminal. No connect. Charge pump output. Requires 1µF bypass capacitor to ground. Flying capacitor 2 positive terminal. Flying capacitor 2 negative terminal. Ground. No connect. Input power supply. Requires 1µF bypass capacitor to ground. Control pin using S2Cwire serial interface. Current source output 1. Required reference current source. Do not leave pin floating. Exposed paddle (bottom); connect to GND directly beneath package.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 EP
7 6 5 N/A N/A 4 3 N/A 2 1 12 11 N/A 10 9 8
Pin Configuration
TSOPJW-12 (Top View) AAT3113 QFN44-16 (Top View) AAT3114/14A
EN/SET
15
NC VIN
14 13
D1
16
C2+ OUT C1C1+ D4 D3
1 2 3 4 5 6
12 11 10 9 8 7
C2GND VIN EN/SET D1 D2
D2 D3 D4 D5
1
12
GND C2C2+ OUT
2
11
3
10
4
9
5
6
7
8
C1+ D6
NC C1-
2
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High Efficiency 1.5X Fractional Charge Pumps For White LED Applications Part Number Descriptions
Part Number
AAT3113ITP AAT3114ISN AAT3114AISN
AAT3113, AAT3114/14A
VIN Range
3.0V ≤ VIN ≤ 5.5V 3.2V ≤ VIN ≤ 5.5V
Number of LED Outputs, 20mA Full-Scale
4 6
LED Present Detect Current
2µA 2µA 150µA
Package
TSOPJW-12 QFN44-16
Absolute Maximum Ratings
TA = 25°C, unless otherwise noted. Symbol
VIN VOUT VEN/SET VEN/SET(MAX) IOUT θJA TJ
Description
Input Voltage Charge Pump Output EN/SET to GND Voltage Maximum EN/SET to Input Voltage Maximum DC Output Current (sum of IOUT and D currents) Thermal Resistance Operating Junction Temperature Range
Value
-0.3 to 6 -0.3 to 6 -0.3 to 6 0.3 150 37 -40 to 150
Units
V V V V mA °C/W °C
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High Efficiency 1.5X Fractional Charge Pumps For White LED Applications Electrical Characteristics
VIN = 3.5V, TA = -40°C to +85°C, unless otherwise noted. Typical values are at TA = 25°C. Symbol Description Conditions Min Typ Max Units
2.7 Active, No Load Current EN = 0 AAT3113: 3.0V ≤ VIN ≤ 5.5V TA = 25°C, All AAT3114/14A: 3.2V ≤ VIN ≤ 5.5V Outputs Max Current 3.0V ≤ VIN ≤ 5.5V VD1:Dn = 3.6V, VIN = 3.3V VIN = 3.5V, IOUT(total) = 40mA 1 18 -2 0.3 93 400 600 20 5.5 2 1 22 2 V mA µA mA %/V % % µs kHz V V µs ns 500 1 µs µA
AAT3113, AAT3114/14A
Input Power Supply VIN Operation Range ICC Operating Current ISHDN Shutdown Current IDX ΔID/ΔVIN Output Current
Output Current Line Regulation Current Matching I(D-Match) Between Any Two O.