ST STP4CMP带电荷泵四路LED驱动解决方案

关键词： LED驱动 , ST , STP4CMP , 电荷泵

ST公司的STP4CMP是基于电荷泵的四路LED驱动器,设计用于RGB照明或LCD显示器背光.支持正向电压高达成3.8V的LED,工作电压 2.7 V到5.5 V,四路电流可单独编程,最大电流30mA,输出电流精度 ±7%,通路间电流匹配度在 ±4%内.主要用在手机显示器背光和RGB LED指示器驱动器.本文介绍了STP4CMP主要特性,框图,典型应用电路及其所用元件,STP4CMP评估板及其电路图,STEVAL-TLL012V1演示板主要特性和电路图,材料清单.

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应用:

■ Mobile phone display backlighting

■ RGB LED indicator drivers

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图1.STP4CMP方框图

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图2.STP4CMP应用框图
图2应用电路外接元件:

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图3.STP4CMP评估板外形图

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图4.STP4CMP评估板电路图

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

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