EUP2571 EUTECH | Alldatasheet
Document overview
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Technical content
D S 2 5 7 1 V e r 1 . 1 M a y . 2 0 0 7 White LED Step-Up Converter In Tiny SOT-23 Package
DESCRIPTION
The EUP2571 is a constant current step-up converter specifically designed to drive white LEDs. The Step-up converter topology allows series connection of the white LEDs so the LED currents are identical for uniform brightness. The EUP2571 switches at 1.1MHz, allowing the use of tiny external components. The input and output capacitor can be as small as 1µF, saving space and cost versus alternative solutions. A low 0.25V feedback voltage minimizes power loss in the current setting resistor for better efficiency. The EUP2571 is available in low profile SOT23-5, SOT23-6 package. Typical Application Circuit
FEATURES
z 2.6V to 5.5V Input Range z 26V Output with Over Voltage Protection z High Efficiency :85 % Typical z PWM Dimming Control z Internal High Power 30V MOSFET Switch z Fast 1.1MHz Switching Frequency z Small, Low-Profile Inductors and Capacitors z SOT23-5,SOT23-6 Package z RoHS Compliant and 100% Lead (Pb)-Free
APPLICATIONS
z PDAs, Handheld Computers z MP3 Players z GPS Receivers Figure 1. White LED Application
Figure 2. 5V to 9V/300mA Step-Up Application MOSFET turns off until V OUT drops below 25V, then the IC reenters start. Connect a 1uF capacitor from OUT to GND.
D S 2 5 7 1 V e r 1 . 1 M a y . 2 0 0 7
Ordering Information
Order Number Package Type Markin g Operating Temperature range EUP2571VBIR1 SOT23-5 V0 □ □ □ -40 °C to 125°C EUP2571VCIR1 SOT23-6 V0 □ □ □ -40 °C to 125°C Lead Free Code 1 : L e a d F r e e 0 : L e a d Packing R : T a p e & R e e l Operating temperature range I: Industry Standard Package Type V : S O T 2 3 V B : S O T 2 3 - 5 V C : S O T 2 3 - 6 Block Diagram Figure 3.
D S 2 5 7 1 V e r 1 . 1 M a y . 2 0 0 7 Absolute Maximum Ratings Power dissipation, PD@ TA=25°C Package Thermal Resistance Operating Conditions
Electrical Characteristics
(VIN =3.6V , VOUT=12V, COUT=1µF, CIN=1µF, RSENSE=12Ω, TA=-40°C to 85°C. Unless otherwise noted. Typical values are at TA= 25°C) EUP2571 Symbol Parameter Conditions Min Typ Max. Unit Supply V oltage -- -- 6 V UVLO Under voltage Lock Out VIN rising or falling 2.2 2.4 2.6 V Maximum Output V oltage -- -- 26 V ICC1 Supply Current V CC=6V , Continuous Switching -- 0.8 1.5 mA ICC2 Quiescent Current V CC=6V , FB=1.3V , No Switching -- 115 250 µA ICC3 Shut Down current V CC=6V , VEN<0.4V -- 0.1 1 µA Oscillator Fosc Operation Frequency 0.8 1.1 1.3 MHz Dmax Maximum Duty Cycle 89 92 96 % Reference Voltage TA=25℃ 237 250 263 VFB Feedback V oltage TA=-40°C to 85°C 230 250 270 mV MOSFET Rds (on) On resistance of MOSFET -- 1.05 1.5 Ω ILX Current Limit 0.4 0.75 1.2 A Control and Protection VEN1 Shut Down V oltage 0.4 0.7 -- V VEN2 Enable V oltage -- 0.7 1.2 V IEN EN Pin Pull Low Current -- -- 0.1 µA
D S 2 5 7 1 V e r 1 . 1 M a y . 2 0 0 7 Typical Operating Characteristics Efficiency vs. Vin (Driving 1WLED) Efficiency vs. Vin (Driving 3WLEDs) Efficiency vs. Vin (Driving 7WLEDs) Efficiency vs. Vin (Driving 2WLEDs) Efficiency vs. Vin (Driving 5WLEDs)
D S 2 5 7 1 V e r 1 . 1 M a y . 2 0 0 7
D S 2 5 7 1 V e r 1 . 1 M a y . 2 0 0 7
D S 2 5 7 1 V e r 1 . 1 M a y . 2 0 0 7
D S 2 5 7 1 V e r 1 . 1 M a y . 2 0 0 7
D S 2 5 7 1 V e r 1 . 1 M a y . 2 0 0 7 Packaging Information SOT23-5 MILLIMETERS INCHES SYMBOLS MIN. MAX. MIN. MAX. A - 1.30 - 0.052 A1 0.00 0.15 0.000 0.006 D 2.90 0.114 E1 1.60 0.063 E 2.60 3.00 0.102 0.118 L 0.30 0.60 0.012 0.024 b 0.30 0.50 0.012 0.020 e 0.95 0.037
D S 2 5 7 1 V e r 1 . 1 M a y . 2 0 0 7 Packaging Information SOT23-6 MILLIMETERS INCHES SYMBOLS MIN. MAX. MIN. MAX. A - 1.45 - 0.057 A1 0.00 0.15 0.000 0.006 b 0.30 0.50 0.012 0.020 D 2.90 0.114 E1 1.60 0.063 e 0.95 0.037 E 2.60 3.00 0.102 0.118 L 0.3 0.60 0.012 0.024