LM3554_16 Datasheet, PDF (1/47 Pages) Texas Instruments – Synchronous Boost Converter

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LM3554
SNVS549C – JUNE 2009 – REVISED FEBRUARY 2016
LM3554 Synchronous Boost Converter With 1.2-A Dual High-Side LED Drivers and I²C-
Compatible Interface
1 Features
•1 Input Voltage: 2.5 V to 5.5 V
• Programmable 4.5-V or 5-V Constant Output
Voltage
• Dual High-Side Current Sources
• Grounded Cathode Allowing for Better Heat
Sinking and LED Routing
• > 90% Efficiency
• Ultra-Small Solution Size: < 23 mm²
• Four Operating Modes: Torch, Flash, LED
Indicator, and Voltage Output
• Accurate and Programmable LED Current from
37.5 mA to 1.2 A
• Hardware Flash and Torch Enable
• LED Thermal Sensing and Current Scaleback
• Software Selectable Input Voltage Monitor
• Programmable Flash Timeout
• Dual Synchronization Inputs for RF Power-
Amplifier Pulse Events
• Open and Short LED Detection
• Active High Hardware Enable for Protection
Against System Faults
• 400-kHz I²C-Compatible Interface
2 Applications
• Camera Phone LED Flash Controller
• Class D Audio Amplifier Power
• LED Current Source Biasing
3 Description
The LM3554 is a 2-MHz fixed-frequency, current-
mode synchronous boost converter. The device is
designed to operate as a dual 600-mA (1.2 A total)
constant-current driver for high-current white LEDs, or
as a regulated 4.5-V or 5-V voltage source.
The main features include: an I²C-compatible
interface for controlling the LED current or the desired
output voltage, a hardware flash enable input for
direct triggering of the flash pulse, and dual TX inputs
which force the flash pulse into a low-current torch
mode allowing for synchronization to RF power
amplifier events or other high-current conditions.
Additionally, an active high hardware enable (HWEN)
input provides a hardware shutdown during system
software failures.
Five protection features are available within the
LM3554 including a software selectable input voltage
monitor, an internal comparator for interfacing with an
external temperature sensor, four selectable current
limits to ensure the battery current is kept below a
predetermined peak level, an overvoltage protection
feature to limit the output voltage during LED open
circuits, and an output short circuit protection which
limits the output current during shorts to GND.
Device Information⁽¹⁾
PART NUMBER
PACKAGE
BODY SIZE (MAX)
LM3554
DSBGA (16)
1.685 mm × 1.685
mm
(1) For all available packages, see the orderable addendum at
the end of the data sheet.
Typical Application Circuit
2.2 µH
2.5 V ± 5.5 V
4.7 µF
SW
IN
OUT
HWEN
SCL
LED1
SDA
LED2
STROBE
TX1/TORCH/
GPIO1
LEDI/NTC
ENVM/TX2
/GPIO _GND
4.5-V or 5-V DC Power Rail
4.7 µF
Flash
LEDs
D2
D1
Indicator
LED
0.1 µF
VBIAS
RBIAS
2 NŸ
Thermistor
1
An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,
intellectual property matters and other important disclaimers. PRODUCTION DATA.