Product details


Input voltage (type) Linear Topology Charge pump Vin (Min) (V) 2.7 Vin (Max) (V) 5.5 Iout (Max) (A) 5 Iq (Typ) (mA) 0.168 Features OVP Operating temperature range (C) -30 to 85 Dimming method Analog, PWM open-in-new Find other Illumination LED drivers

Package | Pins | Size

UQFN (NHU) 20 8 mm² 3 x 2.5 open-in-new Find other Illumination LED drivers


  • Up to 5 A Flash Current
  • 4 Selectable Super-Capacitor Charge Voltage Levels (4.5 V, 5 V, 5.3 V, Optimized)
  • Adjustable Torch Current (60 mA to 200 mA)
  • Ambient Light or LED Thermal Sensing With Current Scaleback
  • Dedicated Indicator LED Current Source
  • No Inductor Required
  • Programmable Flash Pulse Duration, and Torch and Flash Currents via I2C-Compatible Interface
  • True Shutdown (LED Disconnect)
  • Flash Timeout Protection
  • Low Profile 20-Pin UQFN Package
    (3 mm × 2.5 mm × 0.8 mm)
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The LM3550 device is a low-noise, switched-capacitor DC-DC converter designed to operate as a current-limited and adjustable (up to 5.3 V) super-capacitor charger. The LM3550 features user-selectable termination voltages and provides one adjustable constant current output (up to 200 mA) and one NFET controller ideal for driving one or more high-current LEDs in a high-power flash mode or a low-power torch mode.

The LED current and flash pulse duration of the LM3550 can be programmed via an I2C-compatible interface. The STROBE pin allows the flash to be toggled via a flash-enable signal from a controller or camera module. The EOC pin sinks current when the output voltage reaches 95% of the final value.

The ALD/TEMP input pin allows either a light sensor to adjust the flash-current level based on the ambient light conditions, or it allows for over-temperature detection and protection of the LED during high-power operation or high ambient-temperature conditions.

For all available packages, see the orderable addendum at the end of the data sheet.
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Technical documentation

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Type Title Date
* Data sheet LM3550 5-A Super-Capacitor Flash LED Driver datasheet (Rev. C) Oct. 19, 2016
White paper Common LED Functions and LED Driver Design Considerations Sep. 21, 2020
Selection guide Power Management Guide 2018 (Rev. R) Jun. 25, 2018
Technical article Here's how body electronics and lighting technology are changing the driving experience Sep. 26, 2016
Technical article LED brightness adjustment: high-frequency PWM dimming Aug. 26, 2016
Technical article Take better selfies with innovative LED flashes Nov. 18, 2014
Technical article Solving the automotive EMI issues in new cars with all the screens Sep. 11, 2014

Design & development

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PSpice® for TI design and simulation tool
PSPICE-FOR-TI — PSpice® for TI is a design and simulation environment that helps evaluate functionality of analog circuits. This full-featured, design and simulation suite uses an analog analysis engine from Cadence®. Available at no cost, PSpice for TI includes one of the largest model libraries in the (...)
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Reference designs

Piezo Speaker Strobe Notification Reference Design
TIDA-00376 TIDA-00376 uses our industrial piezo driver, flash LED driver and the ultra-low-power FRAM microcontroller (MCU) to demonstrate the implementation of both audible and visual notification subsystems primarily intended for fire alert end-equipment systems. This reference design demonstrates (...)
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