数据搜索系统,热门电子元器件搜索 |
|
TL4242 数据表(PDF) 1 Page - Texas Instruments |
|
|
TL4242 数据表(HTML) 1 Page - Texas Instruments |
1 / 14 page 1 FEATURES 1 2 3 4 8 7 6 5 DRJ (QFN) PACKAGE (TOP VIEW) I NC Q D PWM ST GND REF NC – No internal connection Exposed Thermal Pad DESCRIPTION/ORDERING INFORMATION TL4242 www.ti.com .............................................................................................................................................................. SLVS641A – APRIL 2008 – REVISED MAY 2009 ADJUSTABLE LED DRIVER • Adjustable Constant Current up to 500 mA (±5%) • Wide Input Voltage Range up to 42 V • Low Drop Voltage • Open-Load Detection • Overtemperature Protection • Short-Circuit Proof • Reverse-Polarity Proof • Wide Temperature Range: –40°C to 150°C The TL4242 is an integrated adjustable constant-current source, driving loads up to 500 mA. The output current level can be adjusted via an external resistor. The device is designed to supply high-power LEDs (for example, OSRAM Dragon LA W57B) under the severe conditions of automotive applications, resulting in constant brightness and extended LED lifetime. It is provided in the DRJ (QFN) package. Protection circuits prevent damage to the device in case of overload, short circuit, reverse polarity, and overheat. The connected LEDs are protected against reverse polarity as well as excess voltages up to 45 V. The integrated PWM input of the TL4242 permits LED brightness regulation by pulse-width modulation (PWM). Due to the high input impedance of the PWM input, the LED driver can be operated as a protected high-side switch. The TL4242 is characterized for operation from –40°C to 150°C. An external shunt resistor in the ground path of the connected LEDs is used to sense the LED current. A regulation loop holds the voltage drop at the shunt resistor at a constant level of 177 mV (typical). The constant-current level can be adjusted by selecting the shunt resistance, RREF. Calculate the typical output current using the equation: IQ,typ = VREF/RREF where VREF is the reference voltage (typically 177 mV) (see Reference Electrical Characteristics). The equation applies for RREF = 0.39 Ω to 10 Ω. The output current is shown as a function of the reference resistance in Figure 1. With the PWM input, the LED brightness can be regulated via duty cycle. Also, PWM = L sets the TL4242 in sleep mode, resulting in a very low current consumption of <1 µA (typical). Due to the high impedance of the PWM input (see Figure 4), the PWM pin also can be used as an enable input. ORDERING INFORMATION(1) TJ PACKAGE(2) ORDERABLE PART NUMBER TOP-SIDE MARKING –40°C to 150°C QFN – DRJ Reel of 1000 TL4242DRJR T4242 (1) For the most current package and ordering information, see the Package Option Addendum at the end of this document, or see the TI web site at www.ti.com. (2) Package drawings, thermal data, and symbolization are available at www.ti.com/packaging. 1 Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet. PRODUCTION DATA information is current as of publication date. Copyright © 2008–2009, Texas Instruments Incorporated Products conform to specifications per the terms of the Texas Instruments standard warranty. Production processing does not necessarily include testing of all parameters. |
类似零件编号 - TL4242 |
|
类似说明 - TL4242 |
|
|
链接网址 |
隐私政策 |
ALLDATASHEETCN.COM |
ALLDATASHEET是否为您带来帮助? [ DONATE ] |
关于 Alldatasheet | 广告服务 | 联系我们 | 隐私政策 | 链接交换 | 制造商名单 All Rights Reserved©Alldatasheet.com |
Russian : Alldatasheetru.com | Korean : Alldatasheet.co.kr | Spanish : Alldatasheet.es | French : Alldatasheet.fr | Italian : Alldatasheetit.com Portuguese : Alldatasheetpt.com | Polish : Alldatasheet.pl | Vietnamese : Alldatasheet.vn Indian : Alldatasheet.in | Mexican : Alldatasheet.com.mx | British : Alldatasheet.co.uk | New Zealand : Alldatasheet.co.nz |
Family Site : ic2ic.com |
icmetro.com |