TS19377 2A Buck (Step-down) WLED Driver SOP-8 Pin Definition: 1. FB 8. GND 2. EN 7. GND 3. Comp 6. SW 4. Vcc 5. SW General Description TS19377 consists of step-down switching regulator with PWM control. These devise include a reference voltage source, oscillation circuit, error amplifier, internal PMOS and etc. TS19377 provides low-ripple power, high efficiency, and excellent transient characteristics. The PWM control circuit is able to the duty ratio linearly from 0 up to 100%. An enable function, an over current protect function and short circuit protect function are built inside, and when OCP or SCP happens, the operation frequency will be reduced. Also, an internal compensation block is built in to minimum external component count. With the addition of an internal P-channel Power MOS, a coil, capacitors, and a diode connected externally, these ICs can function as step-down switching regulators. They serve as ideal power supply units for portable devices when coupled with the SOP-8 package, providing such outstanding features as low current consumption. Since this converter can accommodate an input voltage up to 23V, it is also suitable for the operation via an AC adapter. Features Application ● Input Voltage Range 3.6V~23V ● White LED Backlighting ● Output voltage: 0.25V~Vcc ● White LED Driving ● 2A Switch Output Current ● Multiple LED Driving ● Duty ratio: 0%~100% PWM control ● LED Lighting Equipment ● 330kHz Switching Frequency ● Enable/Disable Functions ● Current limit and Thermal Shutdown ● Short Circuit Protections ● Built-in Internal SW P-CH MOS Ordering Information Part No. Package Packing TS19377CS RLG SOP-8 2.5Kpcs / 13” Reel Note: “G” denotes Halogen Free Product. Block Diagram SW Oscillator Circuit Vcc Reference Voltage + PWMSwitched Control Circuit Thermal Shutdown VEN - FB Vss Current Limit Comp EN 1/7 Version: A11 TS19377 2A Buck (Step-down) WLED Driver Absolute Maximum Rating Parameter Symbol Limit Unit VCC Pin Voltage VCC VSS - 0.3 to VSS + 25 V Feedback Pin Voltage VFB VSS - 0.3 to VCC V ON/OFF Pin Voltage VEN VSS - 0.3 to VCC + 0.3 V Switch Pin Voltage VSW VSS - 0.3 to VCC + 0.3 V Power Dissipation PD Internally limited mW Storage Temperature Range TST -40 to +150 °C Operating Temperature Range TOP -40 to +125 °C Operating Supply Voltage VOP +3.6 to +23 V Thermal Resistance from Junction to case θJC 25 °C/W Electrical Specifications (VIN=12V, TA =25oC, unless otherwise noted) Parameter Symbol Conditions Min Typ Max Units 0.24 0.25 0.26 V Feedback Voltage VFB IOUT=0.2A Quiescent Current ICCQ VFB=1.2V force driver off -- 3 5 mA Feedback Bias Current IFB IOUT=0.1A -- 0.1 0.5 uA Shutdown Supply Current ISD VEN =0V -- 2 10 uA Switch Current ISW 2.5 -- -- A Line Regulation △VOUT/VOUT VCC=5V~23V, IOUT=0.2A -- 1 2 % Load Regulation △VOUT/VOUT IOUT=0.1 to 2A -- 0.2 0.5 % 260 330 400 KHz Oscillation Frequency EN Pin Logic input threshold voltage EN Pin Input Current FOSC VSH High (regulator ON) 2.0 -- -- VSL Low (regulator OFF) -- -- 0.8 ISH VEN=2.5V (ON) -- 20 -- uA ISL VEN=0.3V (OFF) -- -10 -- uA VCC=5V, VFB=0V -- 100 140 VCC=12V, VFB=0V -- 70 100 IOUT=1A -- 91 -- IOUT=2A -- 91 -- -- 140 -- Internal MOSFET RDSON RDSON Efficiency EFFI Thermal shutdown Temp VOUT = 5V TSD 2/7 V mΩ % °C Version: A11 TS19377 2A Buck (Step-down) WLED Driver Typical Application Circuit A: 1W/3W LED*1 for DC Input U1 VCC 1 R1 100K FB 8 VSS 2 EN 3 COMP 4 VCC 7 VSS SW 6 5 SW VOUT L1 D7 22uH (10uH for AX2002A) LED AX2002/A D6 C4 C3 0.1u C2 22u 1N4148 R4 4.7K Option R5 100K 1u D5 C1 B240A 4.7u R2 0.75R/0.33R 1W/3W Recommend Bill of Material: C2 R5 350mA ILED 0.715Ω R2 87.5mW 100uF 0.22K 750mA 0.333Ω 189mW 220uF 0.47K 1000mA 0.250Ω 250mW 330uF 0.47K L1 68uH B: 1W/3W LED*1 for AC Input No output Capacitor U1 1 FB 2 AC 12V IN EN 3 COMP 4 VCC AC D4 AC D3 AC D2 8 VOUT 7 VSS SW 6 5 SW L1 D2 LED AX2002/A R5 AC D1 C3 C2 ILED 350mA 750mA 1000mA VSS R2 0.715Ω 0.333Ω 0.250Ω 87.5mW 189mW 250mW D5 C5 100nF 0.1u R2 B240A C2 100uF 220uF 330uF R5 0.22K 0.47K 0.47K 3/7 L1 68uH Version: A11 TS19377 2A Buck (Step-down) WLED Driver Function Descriptions PWM Control The TS19377 consists of DC/DC converters that employ a pulse-width modulation (PWM) system. In converters of the TS19377, the pulse width varies in a range from 0 to 100%, according to the load current. The ripple voltage produced by the switching can easily be removed through a filter because the switching frequency remains constant. Therefore, these converters provide a low-ripple power over broad ranges of input voltage and load current. Setting ILED Current Application circuit item shows the basic application circuit with TS19377 adjustable output version. The external resistor sets the LED output current according to the following formula: ILED=(0.25V/R2) Resistor select for LED output current setting ILED R2 350mA 0.715Ω 87.5mW 750mA 0.333Ω 189mW 1000mA 0.250Ω 250mW RDS(ON) Current Liming The current limit threshold is setting by the internal circuit. Compensation Please refer the table of application circuit. For DC input, the option circuit for compensation is connecting R4 and a 1N4148 diode to VOUT. In order to protect short circuit and thermal shutdown release for LED. 4/7 Version: A11 TS19377 2A Buck (Step-down) WLED Driver Electrical Characteristics Curve Figure 1. Quiescent Current vs. Temperature Figure 2. Shutdown Current vs. Temperature Figure 3. Feedback Voltage vs. Temperature Figure 4. Feedback Voltage vs. Input Voltage Figure 5. Frequency vs. Temperature Figure 6. Efficiency vs. Output Current 5/7 Version: A11 TS19377 2A Buck (Step-down) WLED Driver SOP-8 Mechanical Drawing DIM A B C D F G K M P R SOP-8 DIMENSION MILLIMETERS INCHES MIN MAX MIN MAX. 4.80 5.00 0.189 0.196 3.80 4.00 0.150 0.157 1.35 1.75 0.054 0.068 0.35 0.49 0.014 0.019 0.40 1.25 0.016 0.049 1.27BSC 0.05BSC 0.10 0.25 0.004 0.009 0º 7º 0º 7º 5.80 6.20 0.229 0.244 0.25 0.50 0.010 0.019 Marking Diagram Y = Year Code M = Month Code for Halogen Free Product (O=Jan, P=Feb, Q=Mar, R=Apl, S=May, T=Jun, U=Jul, V=Aug, W=Sep, X=Oct, Y=Nov, Z=Dec) L = Lot Code 6/7 Version: A11 TS19377 2A 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. 7/7 Version: A11