LM3555 Series

Synchronous boost converter with 500 mA high side LED driver and dual-Mode control interface

Catalog

Synchronous boost converter with 500 mA high side LED driver and dual-Mode control interface

Part	Topology	Current - Output / Channel	Voltage - Supply (Min) [Min]	Dimming	Operating Temperature [Min]	Operating Temperature [Max]	Package / Case	Voltage - Supply (Max)	Internal Switch(s)	Mounting Type	Number of Outputs	Supplier Device Package	Voltage - Output	Type	Applications	Frequency
Texas Instruments LM3555TLX/NOPB	Step-Up (Boost)	500 mA	2.5 V	I2C	-30 °C	85 °C	12-WFBGA	5.5 V		Surface Mount	1	12-DSBGA	9.96 V	DC DC Regulator	Camera Flash	2 MHz
Texas Instruments LM3555TLE/NOPB	Step-Up (Boost)	500 mA	2.5 V	I2C	-30 °C	85 °C	12-WFBGA	5.5 V		Surface Mount	1	12-DSBGA	9.96 V	DC DC Regulator	Camera Flash	2 MHz

Catalog

Synchronous boost converter with 500 mA high side LED driver and dual-Mode control interface

Key Features

• High-Voltage High-Side Current Source Allows for Grounded Cathode LED OperationSynchronous Boost ConverterPeak Converter Efficiency > 90%Accurate and Programmable LED Current Ranging From 60 mA to 500 mAAdaptive LED Current Range Based on LED ConfigurationDedicated Indicator Current SourceDedicated Torch and Strobe PinsDual Mode Control (General Purpose or I2C)Broken Inductor DetectionOutput Overvoltage ProtectionOutput and LED Short-Circuit Protection400-kHz I2C-Compatible InterfaceHigh-Voltage High-Side Current Source Allows for Grounded Cathode LED OperationSynchronous Boost ConverterPeak Converter Efficiency > 90%Accurate and Programmable LED Current Ranging From 60 mA to 500 mAAdaptive LED Current Range Based on LED ConfigurationDedicated Indicator Current SourceDedicated Torch and Strobe PinsDual Mode Control (General Purpose or I2C)Broken Inductor DetectionOutput Overvoltage ProtectionOutput and LED Short-Circuit Protection400-kHz I2C-Compatible Interface

Description

The LM3555 is a 2-MHz fixed-frequency, current-mode synchronous boost converter designed to drive either a single flash LED at 500 mA or two series flash LEDs at 400 mA. A high-voltage current source allows the LEDs to be terminated to the GND plane eliminating the need for an additional return trace back to the device. A dual-mode control interface allows the user to configure the LM3555 with a general-purpose interface using two enable pins for control or an I2C allowing a higher level of control. Both interfaces allow access to the indicator, assist light, and flash modes. A dedicated STROBE pin provides a direct interface to trigger the flash event, while an external TORCH pin provides an additional method for enabling the LEDs in a constant current mode. The LM3555 can adaptively scale the maximum flash level delivered to the LEDs based upon the flash configuration, whether it be a single LED or two LEDs in series. Eight protection features are available on the LM3555 ranging from overvoltage protection to broken inductor detection. The LM3555 has four selectable inductor current limits to help the user select an inductor that is appropriate for the design. The LM3555 is a 2-MHz fixed-frequency, current-mode synchronous boost converter designed to drive either a single flash LED at 500 mA or two series flash LEDs at 400 mA. A high-voltage current source allows the LEDs to be terminated to the GND plane eliminating the need for an additional return trace back to the device. A dual-mode control interface allows the user to configure the LM3555 with a general-purpose interface using two enable pins for control or an I2C allowing a higher level of control. Both interfaces allow access to the indicator, assist light, and flash modes. A dedicated STROBE pin provides a direct interface to trigger the flash event, while an external TORCH pin provides an additional method for enabling the LEDs in a constant current mode. The LM3555 can adaptively scale the maximum flash level delivered to the LEDs based upon the flash configuration, whether it be a single LED or two LEDs in series. Eight protection features are available on the LM3555 ranging from overvoltage protection to broken inductor detection. The LM3555 has four selectable inductor current limits to help the user select an inductor that is appropriate for the design.