</a>LED" title="LED">LED" title="LED">LED驅(qū)動(dòng)器,設(shè)計(jì)用于RGB照明或LCD顯示器背光.支持正向電壓高達(dá)成3.8V的LED,工作電壓 2.7 V到5.5 V,四路電流可單獨(dú)編程,最大電流30mA,輸出電流精度 ±7%,通路間電流匹配度在 ±4%內(nèi).主要用在手機(jī)顯示器背光和RGB LED指示器驅(qū)動(dòng)器.本文介紹了STP4CMP主要特性,框圖,典型應(yīng)用電路及其所用元件,STP4CMP評(píng)估板及其電路圖,STEVAL-TLL012V1演示板主要特性和電路圖,材料清單.

The STP4CMP is a charge pump based 4-channel LED driver designed for RGB illumination or LCD display backlighting. The STP4CMP works off a battery with an input voltage between 2.7 V - 5.5 V. The device generates regulated current sinks with high absolute and channel-tochannel accuracy to drive up to 4 LEDs. It can support LEDs with forward voltage as high as 3.8 V. The current sink for each channel can be set with 4 individual external resistors. Each channel is controlled independently. The PWM control can be applied directly to the 4 EN (enable) pins to provide brightness control. When enabled, the charge pump, which uses a small ceramic bucket capacitor between C1P and C1N, operates to regulate the VOUT with a clamping voltage at typ.

5 V. The tiny QFN20 (1.8 x 3.2 mm) package allows the device to be also used for applications with space limitation.

STP4CMP主要特性:

■ Operating voltage range: VCC (opr) = 2.7 V to 5.5 V

■ Full RGB function support

■ 4-channel LED driver with individual ON/OFF control directly from input pins

■ Individual programmable output current for the 4 channels through 4 external resistors with a max. capability of 30 mA

■ Absolute output current accuracy of max. ±7% and channel-to-channel mismatch of max. ± 4%

■ Selectable charge pump enable/disable

■ Thermal protection

■ Small QFN20 (1.8 x 3.2 mm) package

STP4CMP應(yīng)用:

■ Mobile phone display backlighting

■ RGB LED indicator drivers

圖1.STP4CMP方框圖

圖2.STP4CMP應(yīng)用框圖
圖2應(yīng)用電路外接元件:


圖3.STP4CMP評(píng)估板外形圖


圖4.STP4CMP評(píng)估板電路圖

STEVAL-TLL012V1演示板

The STEVAL-TLL012V1 demonstration board demonstrates the performance of the STP4CMP, a charge pump based 4-channel LED driver designed for RGB illumination or LCD display backlighting.

This device works off a battery with an input voltage between 2.7 V - 5.5 V. The device generates regulated current sinks with high absolute and channel-to-channel accuracy to drive up to 4 LEDs. It can support LEDs with forward voltage as high as 3.8 V.

The current sink for each channel can be set with 4 individual external resistors. Each channel is controlled independently.

The PWM control can be applied directly to the 4 EN (enable) inputs to provide brightness control.

STEVAL-TLL012V1演示板主要特性:

■ Operating voltage range: 2.7 V to 5.5 V

■ Full RGB function support

■ 4-channel LED driver with individual ON/OFF control directly from input pins

■ Individual programmable output current for the 4 channels through 4 external resistors with a max. capability of 30 mA

■ Absolute output current accuracy of max. ±7% and channel-to-channel mismatch of max. ± 4%

■ Selectable charge pump enable/disable

■ Thermal protection

■ RoHS compliant

圖5.STEVAL-TLL012V1演示板外形圖

圖6.STEVAL-TLL012V1演示板電路圖
STEVAL-TLL012V1演示板材料清單:

詳情請(qǐng)見(jiàn):
http://www.st.com/internet/com/TECHNICAL_RESOURCES/TECHNICAL_LITERATURE/DATASHEET/CD00236423.pdf
和
http://www.st.com/internet/com/TECHNICAL_RESOURCES/TECHNICAL_LITERATURE/DATA_BRIEF/DM00056350.pdf