White LEDs

Blue LEDs

+5V

+5V

+5V

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LED0

LED2

LED1

LED3

LED4

LED5

LED6

LED7

LED8

LED9

LED10

LED11

LED12

LED13

LED14

LED15

RESET

SCL

SDA

5V

SDA

SCL

PORTx.D

Cell Phone Baseband

Controller/PController

A2

A1

A0

GND

SMBUS/I

2

C

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LP3943

SNVS256C – NOVMEBER 2003 – REVISED OCTOBER 2015

LP3943 RGB, White, Blue 16-LED Fun Light Driver

1 Features

3 Description

The LP3943 is an integrated device capable of

1

•

Internal Power-On Reset

independently driving 16 LEDs. This device also

•

Active Low Reset

contains an internal precision oscillator that provides

•

Internal Precision Oscillator

all the necessary timing required for driving each

LED. Two prescaler registers, along with two PWM

•

Variable Dim Rates

registers, provide a versatile duty-cycle control. The

(From 6.25 ms to 1.6 s; 160 Hz to 0.625 Hz)

LP3943

contains

the

ability

to

dim

LEDs

in

•

16 LED Drivers (Multiple Programmable States:

ON, OFF, Input, and Dimming at a Specified

down on bus traffic.

Rate)

Traditionally, dimming LEDs using a serial shift

•

16 Open-Drain Outputs Capable of Driving up to

register such as 74LS594/5 requires a large amount

25 mA per LED

of traffic on the serial bus. The LP3943 instead

requires only the setup of the frequency and duty

2 Applications

cycle for each output pin; from then on, only a single

command from the host is required to turn each

•

Customized Flashing LED Lights for Cellular

individual open drain output to an ON or OFF state,

Phones

or to cycle a programmed frequency and duty cycle.

•

Portable Applications

Maximum output sink current is 25 mA per pin and

•

Digital Cameras

200 mA per package. Any ports not used for

controlling the LEDs can be used for general purpose

•

Indicator Lamps

input/output expansion.

•

General Purpose I/O Expander

•

Toys

Device Information(1)

PART NUMBER

PACKAGE

BODY SIZE (NOM)

LP3943

WQFN (24)

4.00 mm × 4.00 mm

(1) For all available packages, see the orderable addendum at

the end of the data sheet.

Typical Application Circuit

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.