L99LD21屬于集成電路（IC）的LED驅(qū)動(dòng)器。由意法半導(dǎo)體集團(tuán)制造生產(chǎn)的L99LD21LED 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)的類似產(chǎn)品的主要區(qū)別在于，這類器件提供較低的反饋電壓（以提高系統(tǒng)能效），而且通常可對(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。

特性 Features

? AEC-Q100 qualified

? General

– ST SPI communication v4.1

– 5.5 to 24 V Operating battery voltage range

– Load dump protected

– QFN40L 6x6 (wettable flanks) with

exposed pad

– Timeout watchdog and limp home function

– Low standby current

? Boost Section

– Fixed frequency architecture,

programmable by SPI

– Peak current mode control

– Dual phase operation supported

– Input current limitation

– Soft start

– Overvoltage protection (OVP)

– Short feedback failure protection

– Constant voltage control

? Buck section

– Integrated switching mosfets

– Lossless current sensing without need of

external components

– Very accurate LED current setting

programming inductor's peak current and

peak-to-peak current ripple

– Adjustable peak current by SPI

– Adjustable current ripple by SPI

– Integrated PWM generation unit with 10-bit

resolution and phase shift

– Peak current control

– Constant VLED x TOFF architecture

? Protection and diagnostic

– Battery under voltage

– Temperature warning (2 thresholds)

– Overtemperature shutdown

– LED voltage digital feedback through SPI

– Buck outputs short circuit and open load

protection

描述 Description

The L99LD21 is a flexible LED driver, which is

specifically designed for the control of two

independent high brightness LED strings for

automotive front lighting applications. It consists

of a high efficiency monolithic boost controller and

a dual buck converter.

The boost controller integrates a high current gate

driver for an external n-channel mosfet. It delivers

a constant output voltage, up to 60 V, which

supplies the inputs of the two integrated or

external buck converters.

The boost controller of two devices can be

stacked, in order to operate in dual phase for high

power applications, with an interleaving pattern

for an improved input current ripple.

The buck converters integrate n-channel mosfet

which is driven by a bootstrap circuit.

Applications

? Low Beam

? High beam

? Daytime running light

? Turn indicator

? Position light

? Side marker

? Fog light