LM2704 Datasheet | National Semiconductor

LM2704 Micropower Step-up DC/DC Converter with 550m A Peak Current Limit April 2003 LM2704 Micropower Step-up DC/DC Converter with 550m A Peak Current Limit General Description The LM2704 is a micropower step-up DC/DC in a small 5-lead SOT-23 package. A current limited, fixed off-time control scheme conserves operating current resulting in high efficiency over a wide range of load conditions. The 21V switch allows for output voltages as high as 20V. The low 400ns off-time permits the use of tiny, low profile inductors and capacitors to minimize footprint and cost in spaceconscious portable applications. The LM2704 is ideal for LCD panels requiring low current and high efficiency as well as white LED applications for cellular phone back-lighting. The LM2704 can drive up to 8 white LEDs from a single Li-Ion battery. Features n n n n n n n 550m A, 0.7Ω, internal switch Uses small surface mount ponents Adjustable output voltage up to 20V 2.2V to 7V input range Input undervoltage lockout 0.01µA shutdown current Small 5-Lead SOT-23 package Applications n n n n n LCD Bias Supplies White LED Back-Lighting Handheld Devices Digital Cameras Portable Applications Typical Application Circuit FIGURE 1. Typical 20V Application © 2003 National Semiconductor Corporation DS200315 .national. Connection Diagram Top View TJmax SOT23-5 = 125˚C, θJA = 220˚C/W (Note 2) Ordering Information Order Number LM2704MF-ADJ LM2704MFX-ADJ Package Type SOT23-5 SOT23-5 NSC Package Drawing MA05B MA05B Top Mark S28B S28B Supplied As 1000 Units, Tape and Reel 3000 Units, Tape and Reel Pin Description/Functions Pin 1 2 3 4 5 Name SW GND FB SHDN VIN Power Switch input. Ground. Output voltage feedback input. Shutdown control input, active low. Analog and Power input. Connect the ground of the feedback network to an AGND plane which should be tied directly to the GND pin. SHDN(Pin 4): Shutdown Pin. The shutdown pin is an active low control. Tie this pin above...