T6316A

tm TE CH Preliminary T6316A/B Low-Dropout, Constant-Current White LED Bias Supply FEATURES • Up to 400mA LED Bias Current • 3% LED Current Matching • Simple LED Brightness Control • Low 0.05uA Shutdown Current • 2.7V to 5V Supply Voltage Range • SOP-8 Package and Lead-free • VSET Resistor Option : T6316A : External Resistor T6316B : 20, 85, 100, 125, 150, 175, 200, 250, 300 and 350mA Output Current Option by Internal Resistor • Build in Thermat Protect 160 °C GENERAL DESCRIPTION The T6316A/B low-dropout bias supply for white LEDs is a high-performance alternative to the simple ballast resistors used in conventional white LED designs. The T6316A uses a single resistor to set the bias current for four LEDs, which are matched to 3%. The T6316B build in internal resistor to set the bias current for four LED. The T6316A/B advantages over ballast resistors include significantly better LED to LED bias matching, much lower bias variation with supply voltage variation, significantly lower dropout voltage, and in some applications, significantly improved efficiency. The T6316A/B is available in SOP-8 package and lead-free. Applications • Portable Communication Devices • Handheld Electronics • LED/Display Back Light Driver • Lightings PART NUMBER EXAMPLES PART NO. T6316A-D T6316A-DG T6316B-20D T6316B-20DG T6316B-75D T6316B-75DG PACKAGE SOP-8 SOP-8 lead-free SOP-8 SOP-8 lead-free SOP-8 SOP-8 lead-free Vset Output Current resistor External 20mA 20mA 75mA 75mA External Internal Internal Internal Internal T6316B-350D SOP-8 350mA SOP-8 T6316B-350DG 350mA lead-free Internal Internal TM Technology Inc. reserves the right P. 1 to change products or specifications without notice. Publication Date: JUN. 2006 Revision: B tm LED1 LED2 LED3 LED4 TE CH Preliminary T6316A/B PIN ARRANGEMENT(Top view) 1 2 3 4 8 7 6 5 V SET EN VDD V SS SOP-8 T6316A-D LED1 LED2 LED3 LED4 1 2 3 4 8 7 6 5 EN VDD V SS V SS SOP-8 T6316B-D PIN DESCRIPTION SYMBOL T6316A T6316B DESCRIPTION LED 1 Cathode Connection. Current flowing into LED1 is 270/250 times the current flowing into SET. LED1 is high impedance when EN is low. LED 2 Cathode Connection. Current flowing into LED1 is 270/250 times the current flowing into SET. LED2 is high impedance when EN is low. LED 3 Cathode Connection. Current flowing into LED1 is 270/250 times the current flowing into SET. LED3 is high impedance when EN is low. LED 4 Cathode Connection. Current flowing into LED1 is 270/250 times the current flowing into SET. LED4 is high impedance when EN is low. Ground Power supply Enables PN6316A/B signal , H: Ative , L : Power Down . VSET terminal is used to connect an external resistor to set output current. The current flowing into VSET sets the bias current into each LED by ILED_= 250 x ISET. VSET is internally biased to 0.306V. VSET is high impedance when EN is low. LED1 LED2 LED3 LED4 VSS VDD EN VSET 1 2 3 4 5 6 7 8 1 2 3 4 5,6 7 8 - TM Technology Inc. reserves the right P. 2 to change products or specifications without notice. Publication Date: JUN. 2006 Revision: B tm Parameter TE CH Preliminary T6316A/B Symbol VIN TA TLEAD TS Value -0.3 to 6 -40 to +85 300 -65 to +150 1 Unit V °C °C °C W ABSOLUTE MAXIMUM RATINGS Voltage on any pin relative to GND Operating Temperature Rang Maximum Soldering Temperature (at leads, 10 sec) Storage Temperature Rang Continuous Power Dissipation ( TA = +70°C ) Electrical Characteristics (TA = -40 to 85°C unless otherwise noted. Typical values are at TA =25°C, VEN =3.3V, VLED1 = VLED2= VLED3= VLED4= 1V) Symbol VEN ISET ISETR VSET ICM ILED ILSD VIH VIL TTP Description Operating voltage range SET input current range SET to LED current ratio SET bias voltage Maximum LED sink current LED leakage current in shutdown Input high voltage Input low voltage Conditions EN is power supply input T6316A T6316B Min. Typ. Max 2.7 270 250 0.306 3 350 0.01 400 1 5 1400 1600 Unit V uA A/A V % mA uA V ILED / ISET, ISET=400uA ISET=400uA, no loading Each LED LED to LED current matching ISET=400uA, 100mA loading VLED1=VLED2=VLED3=VLED4= 3.3V, EN=GND, TA=+25°C, each LED VEN >VIH for enable, VDD=5V 2.0 VEN 2.0V) to enable the device; drive EN low (< 0.8V) to disable the device. Driving EN low forces LED1, LED2, LED3, LED4 and SET into a high-impedance state. Setting the Output Current SET controls the LED bias current. Current flowing into LED1, LED2, LED3 and LED4 is 270/250 times greater than the current flowing into SET. Set the output current as follows: T6316A ILED = 270 (0.306V / RSET ) T6316B ILED = 250 (0.306V / RSET ) TM Technology Inc. reserves the right P. 4 to change products or specifications without notice. Publication Date: JUN. 2006 Revision: B tm TE CH Preliminary T6316A/B TYPICAL APPLICATION CIRCUITS V+ VDD ON OFF VDD EN LED 1 LED 2 LED 3 LED 4 T6316A SET GND R V+ VDD ON OFF VDD EN LED 1 LED 2 T6316B GND LED 3 LED 4 Very low-cost, high-efficiency solution TM Technology Inc. reserves the right P. 5 to change products or specifications without notice. Publication Date: JUN. 2006 Revision: B tm TE CH Preliminary T6316A/B PACKAGE DIMENSIONS 8-LEAD SOP B B1 K T h e rm a l P a d * J A1 A C1 C2 C F D H E Symbol A A1 B B1 C C1 C2 D E F J K H Min. 5.70 3.75 1.35 0.10 0.31 0.30 0.10 Dimension in mm Typ. 6.00 3.95 1.27 1.55 0.41 0.50 0.15 2.23 REF 2.97 REF 0~8° Max. 6.30 4.10 5.13 1.80 1.75 0.25 0.51 0.70 0.25 Min. 0.224 0.148 0.052 0.001 0.012 0.012 0.004 Dimension in inch Typ. 0.236 0.156 0.050 0.061 0.016 0.020 0.006 0.088 REF 0.117 REF 0~8° Max. 0.248 0.164 0.202 0.071 0.069 0.004 0.020 0.028 0.010 *Note : The thermal pad on the IC’s bottom has to be mounted on the copper foil. To eliminate the noise influence, the thermal pad is suggested to be connected to GND on PCB. In addition, desired thermal conductivity will be improved, if a heat-conducting copper foil on PCB is soldered with thermal pad. The thermal pad enhances the power dissipation. As a result, a large amount of current can be sunk safely in one package. TM Technology Inc. reserves the right P. 6 to change products or specifications without notice. Publication Date: JUN. 2006 Revision: B