TS19372 Buck (Step-down) WLED Driver with External Switch SOT-25 Pin Definition: 1. SW 2. Ground 3. CT 4. ISENSE 5. VIN General Description The TS19372 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 300mA output current to drive external N-channel MOSFET. TS19372 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 ● Output Current Optional by MOSFET ● High Efficiency up to 92% ● Drives up to 3 (1~3W) LEDs @ VIN 12V ● Drives up to 7 (1~3W) LEDs @ VIN 24V ● 180kHz Switching Frequency ● Internal PWM Filter LED Flashlights White LED Backlighting White LED Driving Multiple LED Driving LED Lighting Equipment Ordering Information Part No. Package Packing TS19372CX5 RF SOT-25 3Kpcs / 7” Reel Block Diagram 1/9 Version: D09 TS19372 Buck (Step-down) WLED Driver with External Switch Absolute Maximum Rating Parameter Symbol Limit Unit Input Voltage VIN 40 V Supply Voltage (Recommended) VIN 6 ~ 40 V FB Voltage VFB -0.3 ~ 40 V SW Voltage VSW 36 V Power Dissipation PD 450 mW Ambient Temperature Range TA -40 to +85 o +150 o Junction Temperature Range TJ C C Electrical Specifications (Ta = 25oC, unless otherwise noted) Parameter Symbol 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 CT = 100pF, -- 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 FOSC Current Limit Sense Voltage Switch VCESAT VSENSE VSAT Supply Current ICC Collector off-state Current IC(OFF) Test Conditions 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 Pin Description Pin Function 1 SW 2 Ground 3 Timing Capacitor 4 ISENSE 5 VIN Description Driver Switching Pin Ground Pin. Timing capacitor oscillator input Peak current sense input to monitor the voltage drop across an external resistor to limit the peak current through the circuit Input Voltage Supply pin 2/9 Version: D09 TS19372 Buck (Step-down) WLED Driver with External Switch Application Information Inductor Selection A 100uH inductor is recommended for most TS19372 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 TS19372 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 TS19372. Capacitor Selection For Input capacitor and timing capacitor are able to use small ceramic capacitor for most of TS19372 applications. When AC input, to add a 100µF electric capacitor for input capacitor is recommended. 3/9 Version: D09 TS19372 Buck (Step-down) WLED Driver with External Switch Typical Application Circuit (DC Input) Input Voltage vs. Efficiency Reference Design Information: TS19372CX5 + TSM2318CX VIN Range (V) L (uH) LED (Series) LED (W) Current (mA) R1 (ohm) R2 (ohm) Efficiency (%) 12 24 68 100 3pcs 6pcs 1 1 350 350 0.54 0.54 1k 1k 88 92 TS19372CX5 + TSM4436CS VIN Range (V) L (uH) 1W LED (Series) LED (W) Current (mA) R1 (ohm) R2 (ohm) Efficiency (%) 12 12 12 24 68 68 68 100 3pcs 2pcs 2pcs 6pcs 3 5 5 700 1000 1400 700 0.32 0.22 0.1 1k 1k 1k 24 24 100 100 6pcs 6pcs 0.16 0.11 0.03 1k 1k 1k 88 88 86 92 3 5 5 1000 1400 92 90 Bill of Materials: Designation Description Package Manufacture Remark LED Driver D1 TS19372CX5 SK34A TSM2318CX TSM4436CS 10uF 820pF SOT-25 SMA SOT-23 SOP-8 805 805 TSC TSC TSC TSC Generic Generic -3A, 40V N-CH 40V / 3.9A N-CH 60V / 8A Ceramic Ceramic M1 Cin C1 4/9 Version: D09 TS19372 Buck (Step-down) WLED Driver with External Switch Typical Application Circuit (AC Input) Input Voltage vs. Efficiency Reference Design Information: TS19372CX5 + TSM2318CX VIN Range (V) L (uH) LED (Series) LED (W) Current (mA) R1 (ohm) R2 (ohm) Efficiency (%) 12 24 68 100 3pcs 6pcs 1 1 350 350 0.54 0.54 1k 1k 88 92 TS19372CX5 + TSM4436CS VIN Range (V) L (uH) 1W LED (Series) LED (W) Current (mA) R1 (ohm) R2 (ohm) Efficiency (%) 12 12 12 24 68 68 68 100 3pcs 2pcs 2pcs 6pcs 3 5 5 700 1000 1400 700 0.32 0.22 0.1 1k 1k 1k 24 24 100 100 6pcs 6pcs 0.16 0.11 0.03 1k 1k 1k 88 88 86 92 3 5 5 1000 1400 92 90 Bill of Materials: Designation Description Package Manufacture Remark LED Driver D1 D2.3.4 TS19372CX5 SK34A SS23M TSM2318CX TSM4436CS 10uF 820pF SOT-25 SMA uSMA SOT-23 SOP-8 805 805 TSC TSC TSC TSC TSC Generic Generic -3A, 40V 2A, 30V N-CH 40V / 3.9A N-CH 60V / 8A Ceramic Ceramic M1 Cin C1 5/9 Version: D09 TS19372 Buck (Step-down) WLED Driver with External Switch Typical Application Circuit – Buck Dimming Control Circuit 1W LED 3S1P Bill of Materials: Designation Description Package Manufacture Remark LED Driver D1 M1. M2 M3 L1 R1 R2, R3 R4, R5, R6 C1 C2 TS19372CX5 SK34A TSM2N7002KCX TSM2318CX 100uH 0.1Ω 1kΩ 10kΩ 10uF 820pF SOT-25 SMA SOT-23 SOT-23 -1206 1206 1206 805 805 TSC TSC TSC TSC Generic Generic Generic Generic Generic Generic -3A, 40V 6/9 N-CH 40V / 3.9A Isat >1.5A --Ceramic Ceramic Version: D09 TS19372 Buck (Step-down) WLED Driver with External Switch Typical Application Circuit – Buck ON/OFF Control Circuit 1W LED 3S1P Bill of Materials: Designation Description Package Manufacture Remark LED Driver D1 M1 M2 L1 R1 R2, R3 R4 C1 C2 TS19372CX5 SK34A TSM2N7002KCX TSM2318CX 100uH 0.1Ω 1kΩ 10kΩ 820pF 100uF SOT-25 SMA SOT-23 SOT-23 -1206 1206 1206 805 TSC TSC TSC TSC Generic Generic Generic Generic Generic Generic -3A, 40V 7/9 N-CH 40V / 3.9A Isat >1.5A --Ceramic Tantalum or Electrolysis * AC Input Version: D09 TS19372 Buck (Step-down) WLED Driver with External Switch 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 72 = Devi e 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: D09 TS19372 Buck (Step-down) WLED Driver with External Switch 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: D09