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High Efficiency 1X/1.5X/2X Charge Pump for Six-Channel White LED Applications General Description
The AAT3164 is a low noise, constant frequency charge pump DC/DC converter that uses a trimode load switch (1X), fractional (1.5X), and doubling (2X) conversion to maximize efficiency for white LED applications. The device is capable of driving up to six channels of LEDs at up to 30mA 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 OUT) makes this part ideally suited for small, battery-powered applications. AnalogicTech's patented single-wire Simple Serial Control™ (S2Cwire™) serial digital input is used to enable, disable, and set current for each LED with 16 levels from a maximum of 40mA down to 50µA. The maximum current level is programmed via an external resistor. To save power, the low-current mode supply current can be programmed as low as 70µA. Each output of the AAT3164 is equipped with builtin protection for VOUT short-circuit and auto-disable for LED short-circuit conditions. Built-in soft-start circuitry prevents excessive inrush current during start-up. A low-current shutdown feature disconnects the load from VIN and reduces quiescent current to less than 1µA. The AAT3164 is available in a Pb-free, space-saving, ultra-thin (3x4x0.75mm), thermally-enhanced 16-pin TDFN package.
AAT3164
Features
• •
ChargePump™
•
• • • • • • •
VIN Range: 2.7V to 5.5V Tri-Mode (1X/1.5X/2X) Charge Pump Operation — Maximizes Efficiency and LED VF Coverage — 1MHz Constant Switching Frequency — No Inductors, Low Noise Operation Drives Six Channels of LEDs up to 30mA/ Channel — User-Programmable RSET Sets Maximum LED Current — Excellent LED Channel-to-Channel Current Match Digitally Programmable LED Current with Single-Wire S2Cwire Interface — 16 Current Levels From ILED_MAX to 50µA Low IQ (70µA) for Low Current Mode Operation True Load Disconnect in Shutdown; IQ < 1µA Built-In Thermal Protection Built-In Auto-Disable for Open LED Circuit Automatic Soft-Start Minimizes Inrush Startup Current Small 3x4mm TDFN34-16 Package
Applications
• • • • Color (RGB) Lighting Programmable Current Sinks White LED Backlighting White Photo Flash for Digital Still Cameras
Typical Application
1µF 1µF C1+ IN Li-Ion Battery VNOM = 3.6V
CIN 1µF
C1- C2+
C2OUT
AAT3164
COUT 1µF
D1
D2
D3
D4
D5
D6 OSRAM LW M67C
GND D1 D2 D3 D4 D5 D6
EN/SET
EN/SET
RSET 26.1K 1%
3164.2006.07.1.0
1
Free Datasheet http://www.datasheet4u.com/
High Efficiency 1X/1.5X/2X Charge Pump for Six-Channel White LED Applications Pin Descriptions
Pin #
1 2 3 4 5 6 7 8 9 10, 12 11 13 14 15 16 EP
AAT3164
Symbol
D5 D6 RSET EN/SET C1+ C1OUT C2+ C2GND IN D1 D2 D3 D4
Function
Current sink input #5. Current sink input #6. Connect resistor here to set maximum output current level. 1% resistor is recommended. Enable Input or S2Cwire serial interface control. Flying Capacitor 1 positive terminal. Connect a 1µF ceramic capacitor between C1+ and C1-. Flying Capacitor 1 negative terminal. Charge pump output to drive load circuit. Requires 1µF ceramic capacitor connected between this pin and ground. Flying Capacitor 2 positive terminal. Connect a 1µF ceramic capacitor between C2+ and C2-. Flying Capacitor 2 negative terminal. Ground. Input power supply. Requires 1µF ceramic capacitor connected between this pin and ground. Current sink input #1. Current sink input #2. Current sink input #3. Current sink input #4. Exposed paddle; connect to GND directly beneath the package.
Pin Configuration
TDFN34-16 (Top View)
D5 D6 RSET EN/SET C1+ C1OUT C2+
1 2 3 4 5 6 7 8
16 15 14 13 12 11 10 9
D4 D3 D2 D1 GND IN GND C2-
2
3164.2006.07.1.0
Free Datasheet http://www.datasheet4u.com/
High Efficiency 1X/1.5X/2X Charge Pump for Six-Channel White LED Applications Absolute Maximum Ratings1
Symbol
VIN VEN/SET IOUT2 TJ TLEAD
AAT3164
Description
Input Voltage EN/SET to GND Voltage Maximum DC Output Current Operating Junction Temperature Range Maximum Soldering Temperature (at leads, 10 sec)
Value
-0.3 to 6 -0.3 to VIN + 0.3 300 -40 to 150 300
Units
V V mA °C °C
Thermal Information3
Symbol
PD θJA
Description
Maximum Power Dissipation Maximum Thermal Resistance
4
Value
2 50
Units
W °C/W
1. Stresses above those listed in Absolute Maximum Ratings may cause permanent damage to the device. Functional operation at conditions other than the operating conditions specified is not implied. Only one Absolute Maximum Rating should be applied at any one time. 2. Based on long-term current density limitation. 3. Mounted on an FR4 board. 4. Derate 20mW/°C above 25°C. 3164.2006.07.1.0
3
Free Datasheet http://www.datasheet4u.com/
High Efficiency 1X/1.5X/2X Charge Pump for Six-Channel White LED Applications Electrical Characteristics1
CIN = COUT = C1 = C2 = 1µF; TA = -40°C to +85°C, unless otherwise noted. Typical.