LM3648 Datasheet, PDF (1/38 Pages) Texas Instruments – Synchronous Boost LED Flash Driver

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LM3648, LM3648TT
SNVSA68B – OCTOBER 2014 – REVISED SEPTEMBER 2015
LM3648 Synchronous Boost LED Flash Driver with 1.5-A High-Side Current Source
1 Features
•1 1.5-A LED Current Source Programmability
• Accurate and Programmable LED Current Range
from 1.954 mA to 1.5 A
• Torch Currents up to 500 mA (LM3648TT)
• Flash Timeout Values up to 1.6 Seconds
(LM3648TT)
• Optimized Flash LED Current During Low Battery
Conditions (IVFM)
• > 85% Efficiency in Torch Mode (at 100 mA) and
Flash Mode (at 1 A to 1.5 A)
• Grounded Cathode LED Operation for Improved
Thermal Management
• Small Solution Size: < 16 mm²
• Hardware Strobe Enable (STROBE)
• Synchronization Input for RF Power Amplifier
Pulse Events (TX)
• Hardware Torch Enable (TORCH/TEMP)
• Remote NTC Monitoring (TORCH/TEMP)
• 400-kHz I²C-Compatible Interface
– LM3648 (I²C Address = 0x63)
2 Applications
Camera Phone White LED Flash
3 Description
The LM3648 is an LED flash driver that provides a
high level of adjustability within a small solution size.
The LM3648 utilizes a 2-MHz or 4-MHz fixed-
frequency synchronous boost converter to provide
power to the 1.5-A constant current LED source. An
adaptive regulation method ensures the current
source remains in regulation and maximizes
efficiency.
Features of the LM3648 are controlled via an I²C-
compatible interface. These features include:
hardware flash and hardware torch pins (STROBE
and TORCH/TEMP), a TX interrupt, and an NTC
thermistor monitor. The device offers 64
programmable currents in Flash and 128 levels in
Movie Mode (Torch) condition.
The 2-MHz or 4-MHz switching frequency options,
overvoltage protection (OVP), and adjustable current
limit allow for the use of tiny, low-profile inductors and
(10-µF) ceramic capacitors. The device operates over
a –40°C to +85°C ambient temperature range.
Device Information⁽¹⁾
PART NUMBER
PACKAGE
BODY SIZE (MAX)
LM3648
DSBGA (12)
1.69 mm x 1.31 mm
(1) For all available packages, see the orderable addendum at
the end of the data sheet.
Simplified Schematic
L1
1 2H
V_IN
2.5V J 5.5V
C1
10 2F
2P/2C
LM3648
IN
SW
HWEN
OUT
SDA
SCL
STROBE
TORCH/
TEMP
TX
LED
GND
C2
10 2F
D1
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.