TPS61054_08 Datasheet, PDF (1/27 Pages) Texas Instruments – HIGH POWER WHITE LED DRIVER 2-MHz SYNCHRONOUS BOOST CONVERTER WITH STANDARD LOGIC INTERFACE

CSP-12
QFN-10
TPS61054, TPS61055
www.ti.com .................................................................................................................................................. SLUS760A – SEPTEMBER 2007 – REVISED MAY 2008
HIGH POWER WHITE LED DRIVER
2-MHz SYNCHRONOUS BOOST CONVERTER WITH STANDARD LOGIC INTERFACE
FEATURES
1
•2 Four Operational Modes
– Torch and Flash up to I_LED = 700 mA
– Voltage-Regulated Boost Converter: 5.0 V
– Shutdown: 0.3 µA (typ)
• Total Solution Circuit Area < 25 mm²
• Up to 96% Efficiency
• Integrated LED Turn-On Safety Timer
• Zero Latency TX-Masking Input
• Integrated Low Light Dimming Mode
• LED Disconnect During Shutdown
• Open/Shorted LED Protection
• Over-Temperature Protection
• Available in a 12-Pin NanoFree™ (CSP) and
10-Pin QFN Packaging
APPLICATIONS
• Camera White LED Torch/Flash for Cell
Phones, Smart-Phones and PDAs
• General Lighting Applications
• Audio Amplifier Power Supply
DESCRIPTION
The TPS6105x device uses a high-frequency
synchronous-boost topology with constant current
sink to drive single white LEDs. The device uses an
inductive fixed-frequency PWM control scheme using
small external components, minimizing input ripple
current.
The 2-MHz switching frequency allows the use of
small and low-profile 2.2-µH inductors. To optimize
overall efficiency, the device operates with only a
250-mV LED feedback voltage.
The TPS6105x device not only operates as a
regulated current source, but also as a standard
voltage-boost regulator. This additional operating
mode can be useful to supply other high-power
devices in the system, such as a hands-free audio
power amplifier, or any other component requiring a
supply voltage higher than the battery voltage.
The LED current or the desired output voltage can be
programmed via two logic signals (MODE0/1). To
simplify flash synchronization with the camera
module, the device offers a trigger pin
(FLASH_SYNC) for fast LED turn-on time.
When the TPS6105x is not in use, it can be put into
shutdown mode, reducing the input current to 0.3 µA
(typ). During shutdown, the LED pin is high
impedance to avoid leakage current through the LED.
L
2.2 mH
C_IN
P
P
TPS61054
SW
SW
AVIN
VOUT
LED
MODE1
MODE0
Tx-TOFF
FLASH_SYNC
AGND
PGND
PGND
C_OUT
10 mF
P
P
Figure 1. Typical Application
+ BATTERY
C1
4.7 mm
INDUCTOR
L1
LED
SENSE
PGND
PGND
C2
LED ANODE
Figure 2. Typical PC-Board Layout
1
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
NanoFree, PowerPAD are trademarks of Texas Instruments.
2
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
Copyright © 2007–2008, Texas Instruments Incorporated