TI公司的TPS92551是恒流降压LED驱动微型模块,最大驱动电流450mA,功率23W,能驱动多达16个LED/串.器件集成了包括电源指示器的所有功率元件,电源效率高达95%,输入电压4.5V-60V,LED电流从300mA到450mA可调整,开关频率800kHz,主要用在通用照明如台灯,装饰灯,街灯,建筑照明如水下照明,壁龛照明和聚光灯等.本文介绍了TPS92551主要特性和封装亮点,方框图,典型应用电路和相应的材料清单,评估板PCB布局图.

The TPS92551 Constant Current Buck LED Driver Micro-Module drives maximum 450mA LED current up to 16 LEDs in a single string (maximum 23W). It integrates all the power components including the power inductor. The TPS92551 provides a full turn-key, highly efficient solution for wide range of single string LED lighting applications with up to 95% power efficiency. It accepts an input voltage ranging from 4.5V to 60V and delivers a 350mA LED current as default. The LED current is adjustable from 300mA to 450mA by charging a single external resistor.

The module operates at constant switching frequency (800kHz) with low Electro Magnetic Interference(EMI) complying with EN55015 standard. The module has fast control loop to realize fine LED current pulse yielding 256–step PWM dimming resolution at 240Hz for general lighting. Protection features include thermal shutdown, input under-voltage lockout, LED open-circuit and short-circuit protections. The TPS92551 Micro-Module is available in TO-PMOD 7 pin power package.

TPS92551封装亮点:

■ 7 lead easy-to-use package (Similar to TO-263)

■ Single exposed die attach pad for enhanced thermal performance 10.2 x 13.8 x 4.6 mm package

TPS92551主要特性:

■ Integrated all power components including the power inductor

■ Wide input voltage range : 4.5V - 60V

■ Constant switching frequency at 800kHz

■ High contrast ratio (Minimum dimming current pulse width < 16μs)

■ Drives up to 16 LEDs in series at 60V input

■ ÷3.5% typical LED current accuracy

■ LED current adjustable from 300mA to 450mA

■ Up to 95% efficiency

■ Input Under-Voltage Lock-Out (UVLO)

■ Compatible with ceramic and low ESR capacitors

■ Low Electro Magnetic Interference (EMI) complies with EN55015 standard

■ LED open and short circuit protections

■ Thermal shutdown and RoHS compliant

■ -40˚C to +125˚C junction temperature range

TPS92551应用:

■ General Lighting

Desk Lamps

Cabinet Lamps

Decorative Lamps

Street Lamps

■ Architecture Lighting

Recess Lights

Spot Lights

Underwater Lights

图1.TPS92551方框图

图2.TPS92551典型应用电路图: VIN = 48V, ILED = 350mA, LED数量 = 5 –13
图2材料清单:


图3.TPS92551典型应用电路图: VIN = 60V , ILED = 350mA , LED数量= 16
图3材料清单:


图4. TPS92551EVM评估板外形图

图5. TPS92551EVM评估板PCB布局图:顶层

图6. TPS92551EVM评估板PCB布局图:底层