AAT3104/AAT3195 新型4通道、电荷泵LED驱动

AAT3104/AAT3195 新型4通道、电荷泵LED驱动器

电源管理集成电路开发商研诺逻辑科技有限公司日前宣布推出AAT3104 和 AAT3195两款新型4通道、电荷泵LED驱动器，它们在简化功能的手机和便携系统中用于更大屏幕LCD显示器。采用紧凑的2 x 2.1mm封装方式，这些器件在一个节省空间的占板内为设计者提供16步进、32步进或脉宽调制(PWM)电流控制。与竞争对手的解决方案相比，AAT3104 和 AAT3195驱动器采用1倍 和2倍模式的高效电荷泵，减少外部组件数量达25%。为了在相邻的LED之间提供统一的亮度和完美匹配，AAT3104 提供用于共阳极结构的通用型电流吸入器，而 AAT3195支持用于共阴极结构的共源。

“工程师为入门级手机或其它便携系统添加新的功能时，通常在其设计中集成更大的显示，”研诺产品线总监Phil Dewsbury说道。“通过为正向偏压LED提供所需的恒流制输出电压，以及控制、设置带有4个LED的共阳极和共阴极结构所需电流的方式，研诺丰富的LED驱动器产品系列新增的这两款芯片，在节省空间的封装内，为便携系统设计师改进设计灵活性，提供较高的功率效率，减少元器件数量以及增加电流控制选择。”

多接口选择

AAT3104是一款电流源LED驱动器，能够为4个LED每个提供最高达30mA电流。基于电荷泵器件可自动在1倍和 2倍模式间转换，以将效率最大化，并优化LED电流精确度和匹配度。LED输出电流精确度为+/- 10%。LED输出电流匹配度为+/- 3%。

AAT3104运行的开关频率为1 MHz ，通过研诺专利单线式S2Cwire接口，可提供16步进(AAT3104-1)或32步进(AAT3104-2)LED亮度控制的两个版本。AAT3105的PWM版本即将供货。

对于采用共阴极结构的LED，AAT3195提供一个基于电荷泵的电流源LED驱动器，用于4通道应用。与AAT3104类似，AAT3195可最多为4个LED每个提供最高达30mA电流。AAT3195也可自动在1倍和2倍模式间切换，以保证最高效率、电流精确度和匹配度。LED输出电流精确度为+/- 10%，LED输出电流匹配度为+/- 3%。

AAT3195运行的开关频率为1 MHz，通过不同的接口提供三个版本。AAT3195-1通过S2Cwire接口，可提供32步进调节的30mA电流；AAT3195-2采用S2Cwire接口，支持32步进的20mA电流。AAT3195-3带有PWM接口。

这两款驱动器都带有自动软启动，省电的低电流关断模式并内置温度保护功能。

价格与供货

AAT3104和AAT3195的额定工作温度范围是-40o C到+85o C。都采用2 x 2.1mm, 10-引脚 SC70JW封装。AAT3104在订货量为1000片时每片单价为0.87美元，AAT3195在订货量为1000片时每片单价为0.87美元。

4-channel LED drivers from AnalogicTech

AnalogicTech has introduced the AAT3104 and AAT3195, two 4-channel, charge pump-based LED drivers for larger LCD screens in reduced feature set cell phones and portable systems. Available in compact 2 x 2.1mm packages, the devices offer designers 16-step, 32-step or PWM current control in a space-saving footprint. By using an efficient charge pump with 1x and 2x modes, the AAT3104 and AAT3195 drivers reduce the external component count by 25% over competing solutions.
To deliver uniform brightness and excellent matching between adjacent LEDs, the AAT3104 provides common current sinks for command anode configurations, while the AAT3195 supports common sources for common cathode configurations.

As engineers add new functionality to entry-level cell phones and other portable systems, they often integrate larger displays into their designs. By providing the required compliance voltage to forward bias the LED as well as a means to control and set the desired current for both common anode and common cathode configurations with four LEDs, these additions to AnalogicTech’s extensive LED driver product portfolio offer portable system designers improved design flexibility, high power efficiency, lower component count, and multiple current control options in a space-saving package.
The AAT3104 is a current-source LED driver capable of driving up to four LEDs at up to 30mA each. The charge pump-based device automatically switches between a 1x and 2x mode to maximize efficiency and optimize LED current accuracy and matching. LED output current accuracy is +/-10%. LED output current matching is +/-3%.

The device operates at a 1MHz switching frequency and comes in two versions that offer either 16-step (AAT3104-1) or 32-step (AAT3104-2) control of LED brightness via AnalogicTech’s patented single-wire S2Cwire interface. A PWM version, the AAT3105, will be available shortly.

For LEDs using common cathode configurations, the AAT3195 offers a charge pump-based current-source LED driver for similar 4-channel applications. Like the AAT3104, the AAT3195 drives up to four LEDs at up to 30mA each. The AAT3195 also automatically switches between 1x and 2x mode to maintain excellent efficiency, current matching and accuracy. The AAT3195 operates at a 1MHz switching frequency and comes in three versions with different interfaces. The AAT3195-1 delivers 30mA current across 32-steps using the S2Cwire interface. The AAT3195-2 supports 20mA current across 32 steps also using the S2Cwire interface. And the AAT3195-3 features a PWM interface.

Both drivers feature automatic soft-start, a low-current shutdown mode to conserve power, and integrated thermal protection.

The AAT3104 and AAT3195 are qualified across the -40 to +85 degrees C temperature range. Both drivers are available in 2 x 2.1mm, 10-lead SC70JW packages.