| 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 |
- 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)
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.
