TS19373 800mA Buck (Step-down) WLED Driver SOT-25 Pin Definition: 1. VIN 2. Ground 3. CT 4. ISENSE 5. SW General Description The TS19373 is a continuous mode inductive step-down converter, designed for driving single or multiple series connected LEDs efficiently from a voltage source higher than the LED voltage. The device operates from an input supply between 6V and 40V and provides an externally adjustable output current of up to 800mA. TS19373 includes the output switch and a high-side output current sensing circuit, which uses an external resistor to set the nominal average output current. Features Application ● ● ● ● ● Wide Input Voltage Range 6V~40V 800mA Output Current High Efficiency up to 90% Drives up to 3 (1~3W) LEDs @ VIN 12V Drives up to 7 (1~3W) LEDs @ VIN 24V ● ● ● ● ● ● ● 180kHz Switching Frequency Internal PWM Filter Ordering Information DC/DC or AC/DC LED driver applications Back lighting of flat panel displays Signage and decorative LED lightings Chargers LED Lighting Equipment – MR16, Tube Part No. Package Packing TS19373CX5 RF SOT-25 3Kpcs / 7” Reel Block Diagram 1/9 Version: B09 TS19373 800mA Buck (Step-down) WLED Driver Absolute Maximum Rating Parameter Symbol Input Voltage VIN 40 V Supply Voltage (Recommended) VIN 6 ~ 40 V FB Voltage VFB -0.3 ~ 40 V SW Voltage VSW 36 V Output SW Current ISW 800 mA Ambient Temperature Range TA -40 to +85 o C +150 o C Junction Temperature Range TJ Limit Unit Electrical Specifications (Ta = 25oC, unless otherwise noted) Parameter Min Typ Max Units VIN 6 -- 40 V Line Regulation REGLINE -- 1.4 5 mV Charge Current ICHARGE VIN =6V~40V -- 30 45 uA IDISCHARGE VIN =6V~40V 180 230 290 uA -- 180 -- kHz 250 -- 350 mV ISW = 300mA -- 1.0 1.3 V VIN =6V~40V, CT =1nF -- 3 4 mA 1 100 uA Input Voltage Range Discharge Current Switching Frequency Current Limit Sense Voltage Switch VCESAT Supply Current Collector off-state Current Symbol FOSC VSENSE VSAT ICC IC(OFF) Test Conditions CT =100pF, IDISCHARGE = ICHARGE VCE =40V Note: Low duty cycle pulse techniques are used during test to maintain junction temperature as close to ambient temperature as possible 2/9 Version: B09 TS19373 800mA Buck (Step-down) WLED Driver Application Information Pin Description Pin Function 1 VIN 2 Ground 3 Timing Capacitor Description Input Voltage Supply pin Ground Pin Timing capacitor oscillator input Peak current sense input to monitor the voltage drop across an external 4 ISENSE 5 SW resistor to limit the peak current through the circuit Switching Pin. This is the internal Darlington switch collector Inductor Selection A 100uH inductor is recommended for most TS19373 applications. Although small size and high efficiency are major concerns, the inductor should have low core losses at 180kHz and low DCR (copper wire resistance). Diode Selection Schottky diodes, with their low forward voltage drop and fast reverse recovery, are the ideal choices for TS19373 applications. The forward voltage drop of a Schottky diode represents the conduction losses in the diode while the diode capacitance represents the switching losses. For diode selection, both forward voltage drop and diode capacitance need to be considered. Schottky diodes with higher current ratings usually have lower forward voltage drop and larger diode capacitance, which can cause significant switching losses at the 180kHz switching frequency of the TS19373. Capacitor Selection For Input capacitor and timing capacitor are able to use small ceramic capacitor for most of TS19373 applications. When AC input, to add a 100µF electric capacitor for input capacitor is recommended. 3/9 Version: B09 TS19373 800mA Buck (Step-down) WLED Driver Typical Application Circuit Input Voltage vs. Efficiency Reference Design Information: VIN Range (V) L (uH) LED (Series) LED (W) Current (mA) R1 (ohm) Efficiency (%) 12 24 68 100 3pcs 6pcs 1 1 350 350 0.5 0.5 88 92 Typical Application Circuit – LED Tube Bill of Materials: Designation LED Driver D1,2,3,4,5 L1 R1 Cin C1 C2 Description TS19373CX5 SS14L 100uH 0.5Ω 10uF 200pF 100uF Package SOT-25 SMA -1206 805 805 Manufacture TSC TSC Generic Generic Generic Generic Generic 4/9 Remark -1A, 40V Isat > 500mA -Ceramic Ceramic Tantalum or Electrolysis * AC Input Version: B09 TS19373 800mA Buck (Step-down) WLED Driver Typical Application Circuit – MR16 Reference Design Information: VIN Range (V) L (uH) LED (Series) LED (W) Current (mA) R1 (ohm) Efficiency (%) 12 24 68 100 3pcs 6pcs 1 1 350 350 0.5 0.5 88 92 Bill of Materials: Designation Description Package Manufacture Remark LED Driver TS19373CX5 SOT-25 TSC -- D1,2,3,4,5 SS14L SMA TSC 1A, 40V L1 100uH -- Generic Isat > 500mA R1 0.5Ω 1206 Generic -- Cin 10uF 805 Generic Ceramic C1 200pF 805 Generic Ceramic C2 100uF Generic Tantalum or Electrolysis * AC Input 5/9 Version: B09 TS19373 800mA Buck (Step-down) WLED Driver Typical Application Circuit – Buck Dimming Control Circuit 1W LED 3S1P Bill of Materials: Designation Description Package Manufacture Remark LED Driver TS19373CX5 SOT-25 TSC -- M1, M2 TSM2N7002KCX SOT-23 TSC D1 SS14L SMA TSC 1A, 40V L1 68uH -- Generic Isat > 500mA R1 0.5Ω 1206 Generic -- R6 1kΩ 1206 Generic R7, R8, R9 10kΩ 1206 Generic Cin 10uF 805 Generic Ceramic C1 470pF 805 Generic Ceramic 6/9 Version: B09 TS19373 800mA Buck (Step-down) WLED Driver Typical Application Circuit – Buck ON/OFF Control Circuit 1W LED 3S1P Bill of Materials: Designation Description Package Manufacture Remark LED Driver TS19373CX5 SOT-25 TSC -- M1 TSM2N7002KCX SOT-23 TSC D1 SS14L SMA TSC 1A, 40V L1 68uH -- Generic Isat > 500mA R1 0.5Ω 1206 Generic -- R6 1kΩ 1206 Generic R8 10kΩ 1206 Generic Cin 10uF 805 Generic Ceramic C1 470pF 805 Generic Ceramic 7/9 Version: B09 TS19373 800mA Buck (Step-down) WLED Driver SOT-25 Mechanical Drawing DIM A+A1 B C D E e H L Ө1 S1 SOT-25 DIMENSION MILLIMETERS INCHES MIN MAX MIN MAX. 0.09 1.25 0.0354 0.0492 0.30 0.50 0.0118 0.0197 0.09 0.25 0.0035 0.0098 2.70 3.10 0.1063 0.1220 1.40 1.80 0.0551 0.0709 1.90 BSC 0.0748 BSC 2.40 3.00 0.09449 0.1181 0.35 BSC 0.0138 BSC 0º 10º 0º 10º 0.95 BSC 0.0374 BSC Marking Diagram 73 = Device Code Y = Year Code M = Month Code (A=Jan, B=Feb, C=Mar, D=Apl, E=May, F=Jun, G=Jul, H=Aug, I=Sep, J=Oct, K=Nov, L=Dec) L = Lot Code 8/9 Version: B09 TS19373 800mA Buck (Step-down) WLED Driver Notice Specifications of the products displayed herein are subject to change without notice. TSC or anyone on its behalf, assumes no responsibility or liability for any errors or inaccuracies. Information contained herein is intended to provide a product description only. No license, express or implied, to any intellectual property rights is granted by this document. Except as provided in TSC’s terms and conditions of sale for such products, TSC assumes no liability whatsoever, and disclaims any express or implied warranty, relating to sale and/or use of TSC products including liability or warranties relating to fitness for a particular purpose, merchantability, or infringement of any patent, copyright, or other intellectual property right. The products shown herein are not designed for use in medical, life-saving, or life-sustaining applications. Customers using or selling these products for use in such applications do so at their own risk and agree to fully indemnify TSC for any damages resulting from such improper use or sale. 9/9 Version: B09