RT9300A/B Preliminary Tiny Package, Low Dropout Current Source General Description Features The RT9300A/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 RT9300A/B uses a internal resistor to set the bias current for four LEDs, which are matched to 3%. The RT9300A/B's advantages over ballast resistors include much lower bias variation with supply voltage variation, significantly lower dropout voltage, and in some applications, significantly improved efficiency. The RT9300A/B requires a 60/45mV dropout at a 20/15mA load on each output to match the LED brightness. z Low 60/45mV Dropout at 20/15mA z 3% LED Current Matching Simple LED Brightness Control 2.5V to 5.5V Supply Voltage Range Thermal Shutdown Protection RoHS Compliant and 100% Lead (Pb)-Free z z z z Applications z z z z Next-Generation Wireless Handsets PDAs, Palmtops, and Handy Terminals Digital Cameras, Camcorders Battery-Powered Equipment Ordering Information RT9300A/B Pin Configurations Package Type E : SOT-23-6 (TOP VIEW) Operating Temperature Range P : Pb Free with Commercial Standard G : Green (Halogen Free with Commercial Standard) LED1 LED2 LED3 Sink Current A : 20mA B : 15mA 6 5 4 1 2 3 EN Note : GND LED4 SOT-23-6 RichTek Pb-free and Green products are : `RoHS compliant and compatible with the current require- Note : There is no pin1 indicator on top mark for SOT-23-6 type, and pin 1 will be lower left pin when reading top mark ments of IPC/JEDEC J-STD-020. `Suitable for use in SnPb or Pb-free soldering processes. from left to right. `100%matte tin (Sn) plating. Typical Application Circuit VIN C 0.1uF 6 LED1 PWM 1 EN 5 LED2 4 LED3 3 LED4 RT9300A/B GND 2 Figure 1. Application circuit for backlight. DS9300A/B-02 March 2007 www.richtek.com 1 RT9300A/B Preliminary VIN Keypad LED C 0.1uF 5 6 LED1 1 PWM LED2 4 LED3 3 LED4 RT9300A/B EN GND 2 Figure 2. Application circuit for keypad. Function Block Diagram LED2 LED4 LED1 LED3 EN Bandgap VREF + - UVLO Current Source OTP IREF Functional Pin Description Pin Name 1 EN 2 GND 3 LED4 4 LED3 5 LED2 6 LED1 www.richtek.com 2 Function Chip Enable (Active High). Ground LED4 Cathode Connection. Current flowing into LED4 is Constant. (20mA/15 mA) LED4 is High Impedance when EN is Low. LED3 Cathode Connection. Current flowing into LED3 is Constant. (20mA/15 mA) LED3 is High Impedance when EN is Low. LED2 Cathode Connection. Current flowing into LED2 is Constant. (20mA/15 mA) LED2 is High Impedance when EN is Low. LED1 Cathode Connection. Current flowing into LED1 is Constant. (20mA/15 mA) LED1 is High Impedance when EN is Low. DS9300A/B-02 March 2007 RT9300A/B Preliminary Absolute Maximum Ratings (Note 1) Supply Input Voltage -------------------------------------------------------------------------------------------------- −0.3V to 6V The other pins ---------------------------------------------------------------------------------------------------------- −0.3V to 6V z Power Dissipation, PD @ TA = 25°C SOT-23-6 ---------------------------------------------------------------------------------------------------------------- 0.4W z Package Thermal Resistance (Note 3) SOT-23-6, θJA --------------------------------------------------------------------------------------------------------------------------------------------------------- 250°C/W z Lead Temperature (Soldering, 10 sec.) --------------------------------------------------------------------------- 260°C z Operation Temperature Range ------------------------------------------------------------------------------------- −40°C to 85°C z Junction Temperature ------------------------------------------------------------------------------------------------- 0°C to 125°C z Storage Temperature Range ---------------------------------------------------------------------------------------- −65°C to 150°C z ESD Susceptibility (Note 2) HBM (Human Body Mode) ------------------------------------------------------------------------------------------ 2kV MM (Machine Mode) -------------------------------------------------------------------------------------------------- 200V z z Electrical Characteristics (VIN = 3.7V, TA = 25°C, Unless Otherwise specification) Parameter Symbol Test Condition Min Typ Max Units 2.5 -- 5.5 V -- 2.1 -- V -- 100 -- mV RT9300A -- 20 -- RT9300B -- 15 -- IOUT = 0, -- -- 600 ILED = 20mA -- 60 -- ILED = 15mA -- 45 -- System Supply Input Operation Voltage Range VEN Under Voltage Lock Out V(UVLO) UVLO Hysteresis LED Maximum Sink Current Quiescent Current IEN LED Dropout Voltage LED Current Deviation Matching mA uA mV -- -- 3 % Digital Input High Level VIH VEN > VIH for enable 2.5 -- -- V Digital Input Low Level VIL VEN < VIL for disable -- -- 0.7 V OTP -- 170 -- C OTP Hysteresis -- 10 -- C -- -- 1 uA RT9300A 18 20 22 RT9300B 13.5 15 16.5 Shut Down Current Initial Current DS9300A/B-02 March 2007 IEN VEN = 0.4V mA www.richtek.com 3 RT9300A/B Preliminary Note 1. Stresses listed as the above “Absolute Maximum Ratings” may cause permanent damage to the device. These are for stress ratings. Functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may remain possibility to affect device reliability. Note 2. Devices are ESD sensitive. Handling precaution recommended. Note 3. θ JA is measured in the natural convection at T A = 25°C on a low effective thermal conductivity test board (Single Layer, 1S) of JEDEC 51-3 therm\al measurement standard. Note 4. Floating connection or pull low to disable this function. www.richtek.com 4 DS9300A/B-02 March 2007 RT9300A/B Preliminary Typical Operating Characteristics LED Current vs. Input Voltage 16 16 Output Current (mA) 18 14 LED Current (mA) Output Current vs. VEN 18 LED 1 LED 2 LED 3 LED 4 12 10 8 6 4 14 12 10 8 6 4 2 2 0 0 2 2.5 3 3.5 4 4.5 5 1.5 1.75 2 2.25 Input Voltage (V) 2.5 2.75 3 3.25 3.5 VEN (V) LED Current vs. Temperature IEN Current vs. VEN Supply Voltage 15.5 400 VIN = 3.5V 350 15.4 I EN Current (uA) LED Current (mA) 300 15.3 15.2 250 200 150 100 15.1 50 15 0 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 1.5 2 2.5 3 3.5 4 Temperature (°C) VEN Supply Voltage (V) Dimming Operation EN Pin Shutdown Response 4.5 VEN = 0V to 3V (2V/Div) EN Pin Voltage LED Current EN Pin Voltage (2V/Div) (10mA/Div) LED Current Time (50μs/Div) DS9300A/B-02 March 2007 (10mA/Div) Time (50μs/Div) www.richtek.com 5 RT9300A/B Preliminary VIN Transient Response VIN = 3.2V to 3.7V Input Voltage LED Current (1V/Div) (25mA/Div) Time (100μs/Div) www.richtek.com 6 DS9300A/B-02 March 2007 RT9300A/B Preliminary Outline Dimension H D L C B b A A1 e Symbol Dimensions In Millimeters Dimensions In Inches Min Max Min Max A 0.889 1.295 0.031 0.051 A1 0.000 0.152 0.000 0.006 B 1.397 1.803 0.055 0.071 b 0.250 0.560 0.010 0.022 C 2.591 2.997 0.102 0.118 D 2.692 3.099 0.106 0.122 e 0.838 1.041 0.033 0.041 H 0.080 0.254 0.003 0.010 L 0.300 0.610 0.012 0.024 SOT-23-6 Surface Mount Package Richtek Technology Corporation Richtek Technology Corporation Headquarter Taipei Office (Marketing) 5F, No. 20, Taiyuen Street, Chupei City 8F, No. 137, Lane 235, Paochiao Road, Hsintien City Hsinchu, Taiwan, R.O.C. Taipei County, Taiwan, R.O.C. Tel: (8863)5526789 Fax: (8863)5526611 Tel: (8862)89191466 Fax: (8862)89191465 Email: [email protected] DS9300A/B-02 March 2007 www.richtek.com 7