LP8501 Datasheet, PDF (1/2 Pages) National Semiconductor (TI) – Multi-Purpose 9-Output LED Driver

November 20, 2008
LP8501 PRODUCT BRIEF
Multi-Purpose 9-Output LED Driver
General Description
The LP8501 is a LED driver with 9 outputs, designed to pro-
duce versatile lighting effects for mobile devices. The device
is equipped with an internal program memory, which allows
operation without processor control. Internal program mem-
ory is used by three independent program execution engines
to produce user defined lighting effects for the outputs.
A high-efficiency charge pump enables LED driving over full
Li-Ion battery voltage range. The excellent efficiency over a
wide operating range is achieved by autonomously selecting
the best charge pump gain based on LED forward voltage
requirements. LP8501 is able to automatically enter power-
save mode when LED outputs are not active, thus lowering
idle current consumption down to 10 µA (typ.)
The device has a flexible General Purpose Output (GPO),
which can be used for example as a digital control pin for other
devices. INT pin (interrupt function), which can be used to
notify processor. Trigger input interface, which allows pro-
gram execution start without I²C write.
The device requires only four small and low-cost ceramic ca-
pacitors. The LP8501 is available in a tiny 25–bump 2.27 mm
x 2.27 mm x 0.60 mm micro SMD package (0.4 mm pitch).
Notice: This document is not a full datasheet. For more
information regarding this product or to order samples,
please contact your local National Semiconductor sales
office or visit http://www.national.com/support/dir.html
Features
■ ^{Three independent program execution engines for user}
defined programs with large SRAM memory for storing
lighting programs
■ ^{9 programmable source (high side) driver outputs with}
25.5 mA full-scale current, 8-bit current setting resolution
and 12-bit PWM control resolution
■ ^{Flexible grouping possibility for all 9 outputs including}
GPO into three groups with group PWM and Fade in/ Fade
out controls
■ ^{Built-in LED test}
■ ^{Adaptive charge pump with 1x and 1.5x gain provides up}
to 95% LED drive efficiency and with soft start and
overcurrent/short circuit protection
■ ^{Automatic power save mode; I}_VDD ^{= 10 µA (typ.)}
■ ^{Two wire, I2C-compatible, control interface}
■ ^{Small application circuit}
■ ^{Pin-configured LED powering for LEDs 1 to 6 and for LEDs}
7 to 9
■ ^{Solution area <18 mm2}
Applications
■ ^{Fun lights and indicator lights}
■ ^{LED backlighting and color keypad lighting}
■ ^{Programmable current source}
■ ^{Haptic feedback driver and GPIO expander}
Typical Application
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