T6326A

tm TE CH Preliminary T6326A Low-Dropout, Constant-Current White LED with Channel Control FEATURES • Up to 400mA LED Bias Current • 3% LED Current Matching • Simple LED Brightness Control • Low 0.05uA Shutdown Current • 3V to 5.5V Supply Voltage Range • MSOP-10L Package • Output channel : MSOP-10L package for four channel • LED1~4 Channels ON / OFF states: T6326A-AM with 16 channel states T6326A-BM with 5 channel states • Build in Thermal Protect 140 °C GRNERAL DESCRIPTION The T6326A low-dropout bias supply for white LEDs is a high-performance alternative to the simple ballast resistors used in conventional white LED designs. The T6326A with internal channel on/off select function. The T6326A uses a single resistor to set the bias current for four LEDs, which are matched to 3%. The T6326A 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 T6326A is available in MSOP-10L package. Applications • Cellular Phones • Portable Communication Devices • Handheld Electronics • Digital Cameras • PDAs • LED/Display Back Light Driver • LEDs for Camera Flash PART NUMBER EXAMPLES PART NO. T6326A-AM T6326A-BM PACKAGE MSOP-10L MSOP-10L ON states 16 5 TM Technology Inc. reserves the right P. 1 to change products or specifications without notice. Publication Date: FEB. 2006 Revision: A tm VSET LED1 LED2 LED3 LED4 TE CH Preliminary T6326A PIN ARRANGEMENT(Top view) 1 2 3 4 5 10 9 8 7 6 CH SW EN VDD VSS VSS MSOP-10L PIN DESCRIPTION SYMBOL MSOP -10L DESCRIPTION VSET terminal is used to connect an extermal 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. LED 1 Cathode Connection. Current flowing into LED1 is 250 times the current flowing into SET. LED1 is high impedance when EN is low. LED 2 Cathode Connection. Current flowing into LED1 is 250 times the current flowing into SET. LED2 is high impedance when EN is low. LED 3 Cathode Connection. Current flowing into LED1 is 250 times the current flowing into SET. LED3 is high impedance when EN is low. LED 4 Cathode Connection. Current flowing into LED1 is 250 times the current flowing into SET. LED4 is high impedance when EN is low. Ground Power supply Enables T6326A signal, H: Ative, L : Power Down . Set LED1~4 Channels ON / OFF, the rising edge of CHSW will change next states. VSET LED1 LED2 LED3 LED4 VSS VDD EN CHSW 1 2 3 4 5 6,7 8 9 10 TM Technology Inc. reserves the right P.2 to change products or specifications without notice. Publication Date: FEB. 2006 Revision: A tm Parameter TE CH Preliminary T6326A 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 ILED / ISET, ISET=400uA ISET=400uA Each LED Min. Typ. Max 3 250 0.306 3 350 0.01 400 1 5.5 1400 1600 Unit V uA A/A V % mA uA V LED to LED current matching ISET=400uA VLED1=VLED2=VLED3=VLED4= 3.3V, EN=GND, TA=+25°C, each LED VEN >VIH for enable, VDD=5V 2.5 VEN 2.5V) to enable the device; drive EN low (< 2.2V) to disable the device. Driving EN low forces LED1, LED2, LED3, LED4 and SET into a high-impedance state. CHSW Input The Set LED1~4 Channels ON / OFF , the rising edge of CHSW will change next states. The T6326A with Internal SEL pad Channel function select. The T6326A-AM with 16 channel states: LED[1:4]=[1111],[1110],[1101],[1100], [1011],[1010],[1001],[1000], [0111],[0110],[0101],[0100], [0011],[0010],[0001],[0000] The T6326A-BM with 5 channel states : LED[1:4]=[1111],[1110],[1100],[1000],[0000] Setting the Output Current SET controls the LED bias current. Current flowing into LED1, LED2, LED3 and LED4 is 250 times greater than the current flowing into SET. Set the output current as follows: ILED = 250 (VSET / RSET ) VSET = 0.306V TM Technology Inc. reserves the right P.4 to change products or specifications without notice. Publication Date: FEB. 2006 Revision: A tm TE CH Preliminary T6326A TYPICAL APPLICATION CIRCUITS V+ VDD ON OFF VDD EN LED1 LED2 LED3 LED4 CHSW SET GND R Very low-cost, high-efficiency solution TM Technology Inc. reserves the right P.5 to change products or specifications without notice. Publication Date: FEB. 2006 Revision: A tm TE CH Preliminary T6326A PACKAGE DIMENSIONS 10-LEAD MSOP-10L 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. 0.75 0.00 0.17 0.40 0.10 - Dimension in mm Typ. 4.90 3.00 3.00 0.50 0.85 0.60 0.15 1.715 REF 1.600 REF 0~8° Max. 1.10 0.95 0.15 0.27 0.80 0.25 - Min. 0.029 0.000 0.007 0.015 0.004 - Dimension in inch Typ. 0.193 0.118 0.118 0.019 0.033 0.024 0.006 0.067 REF 0.063 REF 0~8° Max. 0.043 0.037 0.006 0.010 0.031 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: FEB. 2006 Revision: A