LP3943屬于集成電路（IC）的LED驅(qū)動(dòng)器。由美國(guó)德州儀器公司制造生產(chǎn)的LP3943LED 驅(qū)動(dòng)器器件屬于 LED 驅(qū)動(dòng)器電源管理集成電路 (PMIC) 系列，可通過(guò)標(biāo)稱(chēng)固定電壓的電源為負(fù)載（通常為發(fā)光二極管）提供電流，并且電流可控。它與用于電壓調(diào)節(jié)的類(lèi)似產(chǎn)品的主要區(qū)別在于，這類(lèi)器件提供較低的反饋電壓（以提高系統(tǒng)能效），而且通?？蓪?duì)器件工作點(diǎn)進(jìn)行外部控制，可在照明應(yīng)用中用于實(shí)現(xiàn)調(diào)光功能。

1 Features

? Internal power-on reset

? Active low reset

? Internal precision oscillator

? Variable dim rates

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

? 16 LED drivers (multiple programmable states:

ON, OFF, input, and dimming at a specified rate)

? 16 open-drain outputs capable of driving up to

25mA per LED

2 Applications

? Customized flashing LED lights for cellular phones

? Portable applications

? Digital cameras

? Indicator lamps

? General purpose I/O expander

? Toys

3 Description

The LP3943 is an integrated device capable of

independently driving 16 LEDs. This device also

contains an internal precision oscillator that provides

all the necessary timing required for driving each

LED. Two prescaler registers, along with two PWM

registers, provide a versatile duty-cycle control.

The LP3943 contains the ability to dim LEDs in

SMBUS/I2C applications where it is required, to cut

down on bus traffic.

Traditionally, dimming LEDs using a serial shift

register such as 74LS594/5 requires a large amount

of traffic on the serial bus. The LP3943 instead

requires only the setup of the frequency and duty

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

single command from the host is required to turn

each individual open drain output to an ON or OFF

state, or to cycle a programmed frequency and duty

cycle. Maximum output sink current is 25mA per pin

and 200mA per package. Any ports not used for

controlling the LEDs can be used for general purpose

input/output expansion.