LM3552SDEV National Semiconductor, LM3552SDEV Datasheet

Page 1

... The LM3551 and LM3552 are available in a low profile 14-pin LLP package. Typical Application Circuits © 2011 National Semiconductor Corporation LM3551/LM3552 Features ■ total drive current ■ ...

Page 2

Connection Diagram Pin Descriptions Pin Name 9 V Input Voltage. Input range: 2.7V to 5.5V T/F TORCH/FLASH Pin. Low = Torch Mode, High = Flash Mode 8 SW Switch Pin 10 OVP Over Voltage Protection Pin V Compensation ...

Page 3

... ESD Rating(Note 5) Human Body Model ESD Caution Notice National Semiconductor recommends that all integrated circuits be handled with appropriate ESD precautions. Failure to observe proper ESD handling techniques can result in damage to the device. Electrical Characteristics Limits in standard typeface are for T J ≤ ...

Page 4

... T =120ºC (typ.). J Note 4: For detailed soldering specifications and information, please refer to National Semiconductor Application Note: AN-1187 for Recommended Soldering Profiles. Note 5: The human body model is a 100pF capacitor discharged through a 1.5kΩ resistor into each pin. (MIL-STD-883 3015.7) Note 6: Maximum recommended SW pin voltage when the OVP pin is grounded. ...

Page 5

Typical Performance Characteristics (R = 10kΩ 4.7nF 10µF for Lumiled LED OUT C = 1µ 0.1µF. FTO SS Current Limit vs. Input Voltage OUT Note ...

Page 6

Maximum I vs. Input Voltage OUT OUT Note 16: I measured at 95%× V (nominal) OUT OUT LED Torch Current vs. Input Voltage Lumiled Flash LED OVP Trip Voltage vs. Input Voltage www.national.com Maximum I 20151222 Note ...

Page 7

Start-Up Waveform Sharp LED 20151232 Ch1 = V , Ch3 = I , Ch4 = I SD LED IN Typical Switching Waveform 20151233 Sharp LED in Flash Mode Ch1 = V , Ch3 = I , Ch4 = I SW ...

Page 8

Block Diagram Circuit Description OVERVIEW The LM3551/2 are high power white LED flash drivers capa- ble of delivering output current. The devices utilize a highly efficient inductive DC/DC boost converter to achieve the required output voltage. ...

Page 9

OVP pin and any other leakage path. When the output voltage drops to 10.6V(typ), switching will resume. The LM3551 and ...

Page 10

Soft-Start The LM3551 and LM3552 have a soft-start pin that can be used to limit the inductor inrush current on start-up. The ex- ternal SS pin is used to tailor the soft-start for a specific application but is not required ...

Page 11

DIODE SELECTION The output diode for a boost regulator must be chosen cor- rectly depending on the output voltage and output current. The output diode must have a reverse voltage rating equal to or greater than the output voltage used. ...

Page 12

... PCB thermal land. To further enhance thermal con- ductivity, the PCB thermal land may include vias to a ground = 10kΩ for plane. For more detailed instructions on mounting LLP pack- C ages, please refer to National Semiconductor Application Note AN-1187. 12 Value Ratings 2.0A 30 4.7µ ...

Page 13

Application Examples TYPICAL CONFIGURATIONS Note 18: Please refer to the RECOMMENDED MINIMUM COMPONENT section of the datasheet for more information. LUMILED LXCL-PWF1 = 5.6Ω 2.2Ω 200mA 700mA TORCH FLASH SHARP GM5BW05340A ...

Page 14

DUAL-MODE CONFIGURATION Using the Dual-Mode configuration with either the LM3551/2, a 5V, high current rail (approx. 700mA total) can be created while still allowing for a high flash with a true load disconnect. R1 and R2 setup the +5V following ...

Page 15

Physical Dimensions inches (millimeters) unless otherwise noted 15 www.national.com ...

Page 16

... For more National Semiconductor product information and proven design tools, visit the following Web sites at: www.national.com Products Amplifiers www.national.com/amplifiers Audio www.national.com/audio Clock and Timing www.national.com/timing Data Converters www.national.com/adc Interface www.national.com/interface LVDS www.national.com/lvds Power Management www.national.com/power Switching Regulators www.national.com/switchers LDOs www.national.com/ldo LED Lighting www ...