TS2509 3A / 500KHz PWM Buck Converter SOP-8 Pin Definition: 1. FB 8. Vss 2. EN 7. Vss 3. Comp 6. SW 4. Vcc 5. SW General Description TS2509 is step-down switching regulator with PWM control and with build in internal PMOS. TS2509 provides lowripple power, high efficiency, and excellent transient characteristics. The PWM control circuit can be duty ratio linearly form 0 up to 100%. This converter also contains an error amplifier circuit as well as a soft-start circuit that prevents overshoot at startup. An enable, over current protect and short circuit protect functions are built inside. When OCP or SCP activated, the operation frequency will be reduced. The internal compensation block is built in to minimum external components and internal PMOS is complete 3A step down switching regulator ideally for portable devices with outstanding features as low current consumption. Features Ordering Information ● Input Voltage: 3.6V~23V ● Output Voltage: 0.8V~Vcc ● Duty Ratio: 0%~100% PWM Control ● Oscillation Frequency: 500kHz typ. ● Soft-Start (SS), Current Limit (CL), Enable Function Application ● Thermal Shutdown Function ● Simple High-efficiency Step down Regulator ● Short Circuit Protect (SCP) ● On-Card Switching Regulators ● Internal SW P-Channel MOSFET ● Low ESR output capacitor (MLCC application) Part No. TS2509CS RL Package Packing SOP-8 2.5Kpcs / 13” Reel Absolute Maximum Rating Parameter Symbol Rating 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 G -40 to +150 ℃ Operating Temperature Range TOP -20 to +125 ℃ Operating Supply Voltage VOP +3.6 to +23 V Thermal Resistance from Junction to case θJC 40 ℃/W Thermal Resistance from Junction to ambient θJA 70 ℃/W 1/9 Version: B09 TS2509 3A / 500KHz PWM Buck Converter Electrical Specifications (VIN=12V, Ta=25oC unless otherwise noted) Characteristics Symbol Feedback Voltage VFB Quiescent Current Iq Feedback Bias Current Conditions Min Typ Max Units 0.784 0.800 0.816 V VFB =1.2V force driver off -- 3 5 mA IFB IOUT =0.1A -- 0.1 0.5 uA Shutdown Supply Current ISD VEN =0V -- 2 10 uA Current limit ISW 4 -- -- A IOUT =0.1A Line Regulation ∆VOUT/VOUT VCC = 5V~23V, IOUT =0.2A -- 0.6 1.2 % Load Regulation ∆VOUT/VOUT IOUT = 0.1 to 3A -- 0.2 0.4 % KHz Oscillation Frequency FOSC SW pin 400 500 600 EN Pin Logic input VSH High (regulator ON) 2.0 -- -- threshold voltage VSL Low (regulator OFF) -- -- 0.8 ISH VEN =2.5V (ON) -- 20 -- uA ISL VEN =0.3V (OFF) -- -10 -- uA 0.3 4 8 ms VCC = 5V, VFB =0V -- 90 140 VCC = 12V, VFB =0V -- 60 90 IOUT = 2A -- 91 -- IOUT = 3A -- 90 -- -- 125 -- EN Pin Input Current Soft-Start Time Internal MOSFET TSS RDSON Efficiency EFFI Thermal Shutdown Temp. TSD VOUT = 5V V mΩ % ºC Block Diagram Pin Assignment Name FB EN Comp SW Vcc Vss Description Feedback pin H: Normal operation (Step-down) L: Step-down operation stopped (All circuit deactivated) Compensation pin Switch pin. Connect external inductor/diode here IC power supply pin Gnd pin 2/9 Version: B09 TS2509 3A / 500KHz PWM Buck Converter Application Circuit MLCC Compensation Capacitor Selection (MLCC) VIN 7~23V 7~20V 9~20V 9~18V 9~18V 4~10V 4~10V VOUT 5.0/3.3/2.5V 1.8/1.5V 1.2V 1.1V 1.0V 3.3/2.5V 1.8/1.5/1.2/ 1.1/1.0V L1 15uH 10uH 10uH 10uH 10uH 15uH 10uH R3 2.2K 2K 2K 2K 2K 6.8K 4.7K C7 330pF 330pF 330pF 560pF 560pF 330pF 330pF C1 1nF 1nF 820pF 820pF 680pF 1nF 1nF R3 3.9K 2K 2K 0.82K C7 10nF 10nF 10nF 10nF C1 1nF 1nF 1nF 1nF EL CAP Compensation Capacitor Selection (EL CAP) VIN 7-20V 7-20V 5-7V 5-20V VOUT 5.0/3.3/2.5/1.8V 1.8/1.5V 3.3/2.5/1.8/1.5/1.2V 3.3/2.5/1.8/1.5/1.2V L1 Coil Coil Coil SMD 3/9 Version: B09 TS2509 3A / 500KHz PWM Buck Converter Function Descriptions PWM Control The TS2509 is a pulse-width modulation (PWM) system with a range from 0 to 100% according to different load current. The ripple voltage produced by the switching can easily be removed through a filter because the switching frequency remains constant. Setting the Output Voltage TS2509 is adjustable output version. With different output voltage setting, following tables are for external resistor value setting as reference: (EL CAP) Resistor select for output voltage setting VOUT 5V 3.3V 2.5V 1.8V 1.5V 1.2V 1V R2 1.3K 1.5K 2.2K 2K 2.2K 3K 10K (MLCC) Resistor select for output voltage setting R1 6.8K 4.7K 4.7K 2.5K 2K 1.5K 2.5K VOUT 5V 3.3V 2.5V 1.8V 1.5V 1.2V 1V R2 7.5K 15K 22K 27K 30K 30K 56K R1 39K 47K 47K 33K 27K 15K 13K Inductor Selection For most designs are operates with inductors of 10µH to 22µH. The inductor value can be derived from the following table: L1 Recommend Value (VIN=12V, IOUT=3A) VOUT 1.8V 2.5V 3.3V 5V L1 Value 10~15uH 10~15uH 15~22uH 15~22uH Large value inductors can lower ripple current and small value inductors will gets higher ripple currents. Choose inductor ripple current approximately 15% of the maximum load current 3A. Input Capacitor Selection (EL CAP) This capacitor should be located close to the IC using short leads and the voltage rating should be approximately 1.5 times the maximum input voltage. The RMS current rating should be approximately 1⁄2 the DC load current. A low ESR input capacitor sized for maximum RMS current must be used. A 220µF low ESR capacitor for most sufficient for applications (MLCC) A 22µF MLCC or two 10uF MLCC capacitors for most sufficient for applications 4/9 Version: B09 TS2509 3A / 500KHz PWM Buck Converter Function Descriptions (Continue) Output Capacitor Selection (EL CAP) The output capacitor is required to maintain the DC output voltage stability. The important capacitor parameters are; the 100KHz ESR (Equivalent Series Resistance), the RMS ripples current rating, voltage rating, and capacitance value. For the output capacitor, the ESR value is the most important parameter, the ESR can be calculated from the following formula. VRIPPLE = ∆IL x ESR = 0.4A x 110mΩ = 44mV An aluminum electrolytic capacitor's ESR value is related to the capacitance and its voltage rating. In most case, higher voltage electrolytic capacitors have lower ESR values. Most of the time, capacitors with much higher voltage ratings may be needed to provide the low ESR values required for low output ripple voltage. It is recommended to replace this low ESR capacitor by using a 330µF low ESR values < 110mΩ (MLCC) A 33µF MLCC or three 10uF MLCC capacitors is most sufficient for applications. RDS(ON) Current Limiting The current limit threshold is setting by the internal circuit. VIN 4.6V~6V 6V~10V 10V~23V ICL(MIN) 3A 3.8A 4.0A IOUT(MAX) 2.5A 3A 3A Layout Guidance When laying out the PC board, the following suggestions should be taken to ensure proper operation of the TS2509. 1. The power traces, including the PMOS Drain & Source trace, the Schottky and the C2 trace should be kept short, direct and wide to allow large current flow. 2. Connect the C5 to the VCC & EN pins of the TS2509 as closely as possible to get good power filter effect. 3. Keep the switching node, away from the sensitive FB node. 4. Connect ground side of the C2 & D1 as closely as possible. 5. Connect PMOS Source and R3 as closely as possible. 6. Do not trace signal line under inductor. 5/9 Version: B09 TS2509 3A / 500KHz PWM Buck Converter Electrical Characteristics Curve Figure 1. Feedback Voltage vs. Input Voltage Figure 2.Quiescent Current vs. Input Voltage Figure 3. Frequency vs. Input Voltage Figure 4. Frequency vs. Temperature Figure 5. Feedback Voltage vs. Temperature Figure 6. Quiescent Current vs. Temperature 6/9 Version: B09 TS2509 3A / 500KHz PWM Buck Converter Electrical Characteristics Curve Figure 7. Efficiency Figure 8.Output Ripple (VIN=12V, VOUT=5V, IOUT=3A) (VIN=12V, VOUT=5V, IOUT=3A) (VIN=12V, VOUT=5V, IOUT=0.2A) Figure 9.Power On test Wave Figure 10.Power On test Wave (VIN=12V, VOUT=5V, IOUT=0.1~3A) Figure 11. Load Transient Response 7/9 Version: B09 TS2509 3A / 500KHz PWM Buck Converter 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 (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 TS2509 3A / 500KHz PWM Buck Converter 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