Packaging information
| Package | Pins UQFN (NHU) | 20 |
| Operating temperature range (°C) -30 to 85 |
| Package qty | Carrier 1,000 | SMALL T&R |
Features for the LM3550
- 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)
Description for the LM3550
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.