【问】TLC5970

TLC5970 是一款非常有竞争力的实现智能恒流控制 DC-DC Buck 驱动器,恒流精度特别高。每个芯片有三个引脚OUT0，OUT1,OUT2可以分别控制三路负载，是否能三个引脚一起控制一路负载呢？是否这样是不就是负载电流是原来的3倍？

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bdzn

LV.9

2012-07-07 12:41

The TLC5970 is a three-channel, constant-current sink driver with a buck dc/dc converter and a differential signal interface. Each channel has individually adjustable currents with 4096 PWM grayscale (GS) steps and 128 constant-current sink steps for dot correction (DC). The dot correction adjusts the brightness variations between LEDs. The DC data can be stored in the internal EEPROM. Also, current through all three channels can be controlled by global brightness control (BC) data with 128 steps. GS control, DC, and BC are accessible via a differential signal interface. The maximum current value for each channel is set by a single external resistor. The TLC5970 contains a dc/dc buck converter. The dc/dc converter improves system efficiency, reduces system level currents, and allows thinner gauge wiring by optimizing the LED anode voltage to keep the LED cathode voltage to 1 V.

明月光

LV.6

2012-07-07 13:59

可以，但是电流不一定是原来的3倍

电源照宝

LV.8

2012-07-07 15:28

OUT0，OUT1,OUT2恒定电流源输出.多个输出可以连接在一起,可以增加

恒定电流的能力。但要从IREF0, IREF1,和IREF2连接的电阻GND设置电流。

geek

LV.7

2012-07-07 18:41

当然可以的，但电流要做到原来的三倍可能要认真调哦，量产可能不一定。

houtao

LV.6

2012-07-13 22:12

@geek

当然可以的，但电流要做到原来的三倍可能要认真调哦，量产可能不一定。

三个可以一起使用.电流理论上是三倍.从内部结构看是不相关，所以并联可以是相加

starcool

LV.5

2012-07-14 00:15

@bdzn

TheTLC5970isathree-channel,constant-currentsinkdriverwithabuckdc/dcconverterandadifferentialsignalinterface.Eachchannelhasindividuallyadjustablecurrentswith4096PWMgrayscale(GS)stepsand128constant-currentsinkstepsfordotcorrection(DC).ThedotcorrectionadjuststhebrightnessvariationsbetweenLEDs.TheDCdatacanbestoredintheinternalEEPROM.Also,currentthroughallthreechannelscanbecontrolledbyglobalbrightnesscontrol(BC)datawith128steps.GScontrol,DC,andBCareaccessibleviaadifferentialsignalinterface.Themaximumcurrentvalueforeachchannelissetbyasingleexternalresistor.TheTLC5970containsadc/dcbuckconverter.Thedc/dcconverterimprovessystemefficiency,reducessystemlevelcurrents,andallowsthinnergaugewiringbyoptimizingtheLEDanodevoltagetokeeptheLEDcathodevoltageto1V.

以这种后缀区分的器件都是只有封装和包装区别，芯片内核参数都是一样的！

javike

LV.12

2012-07-14 09:15

从IC的内部图来看，三路恒流只有一个电压环FB，IC内部采用的是恒流源的方式控制，

所以3路理论上是可以并联使用的，

但时间使用时为了防止震荡，建议三路并用时在没路串联一个数欧姆的电阻。

电流可以是原来的3倍了，但IREF0,IREF1,IREF2端的电阻需一致。

wf1988

LV.2

2012-07-14 13:11

是的，这样驱动能力增强了但不一定完全3倍。