TS2509

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 consists of step-down switching regulator with PWM control. These devise include a reference voltage source, oscillation circuit, error amplifier, internal PMOS and etc. TS2509 provides low-ripple power, high efficiency, and excellent transient characteristics. The PWM control circuit is able to the 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 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-8L 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 ● ● ● ● ● ● ● ● ● 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 Thermal Shutdown Function Short Circuit Protect (SCP) External SW P-Channel MOSFET Low ESR output capacitor (MLCC application) Ordering Information Part No. TS2509CS RL Package SOP-8 Packing 2.5Kpcs / 13” Reel Application ● ● Simple High-efficiency Step down Regulator On-Card Switching Regulators Absolute Maximum Rating Parameter VCC Pin Voltage Feedback Pin Voltage ON/OFF Pin Voltage Switch Pin Voltage Power Dissipation Storage Temperature Range Operating Temperature Range Operating Supply Voltage Thermal Resistance from Junction to case Thermal Resistance from Junction to ambient Symbol VCC VFB VEN VSW PD TST G TOP VOP θJC θJA Rating VSS - 0.3 to VSS + 25 VSS - 0.3 to VCC VSS - 0.3 to VCC + 0.3 VSS - 0.3 to VCC + 0.3 Internally limited -40 to +150 -20 to +125 +3.6 to +23 40 70 Unit V V V V mW ℃ ℃ V ℃/W ℃/W 1/9 Version: A09 TS2509 3A / 500KHz PWM Buck Converter Electrical Specifications (VIN=12V, Ta=25oC unless otherwise noted) Characteristics Feedback Voltage Quiescent Current Feedback Bias Current Shutdown Supply Current Current limit Line Regulation Load Regulation Oscillation Frequency EN Pin Logic input threshold voltage EN Pin Input Current Soft-Start Time Internal MOSFET Efficiency Thermal Shutdown Temp. Symbol VFB Iq IFB ISD ISW ∆VOUT/VOUT ∆VOUT/VOUT FOSC VSH VSL ISH ISL TSS RDSON EFFI TSD Conditions IOUT =0.1A VFB =1.2V force driver off IOUT =0.1A VEN =0V VCC = 5V~23V, IOUT =0.2A IOUT = 0.1 to 3A SW pin High (regulator ON) Low (regulator OFF) VEN =2.5V (ON) VEN =0.3V (OFF) VCC = 5V, VFB =0V VCC = 12V, VFB =0V IOUT = 2A VOUT = 5V IOUT = 3A Min 0.784 ---4 --400 2.0 ---0.3 ------ Typ 0.800 3 0.1 2 -0.6 0 .2 500 --20 -10 4 90 60 91 90 125 Max 0.816 5 0.5 10 -1.2 0 .4 600 -0.8 --8 140 90 ---- Units V mA uA uA A % % KHz V uA uA ms 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: A09 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 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 R3 3.9K 2K 2K 0.82K 3/9 C7 10nF 10nF 10nF 10nF C1 1nF 1nF 1nF 1nF Version: A09 TS2509 3A / 500KHz PWM Buck Converter Function Descriptions PWM Control The TS2509 consists of DC/DC converters that employ a pulse-width modulation (PWM) system. In converters of the TS2509, 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 the Output Voltage Application circuit item shows the basic application circuit with TS2509 adjustable output version. The external resistor sets the output voltage according to the following equation: (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 R1 6.8K 4.7K 4.7K 2.5K 2K 1.5K 2.5K (MLCC) Resistor select for output voltage setting 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, the operate with inductors of 10µH to 22µH. The inductor value can be derived from the following equation: L1 Recommend Value (VIN=12V, IOUT=3A) VOUT L1 Value 1.8V 10~15uH 2.5V 10~15uH 3.3V 15~22uH 5V 15~22uH Where is inductor Ripple Current. Large value inductors lower ripple current and small value inductors result in high ripple currents. Choose inductor ripple current approximately 15% of the maximum load current 3A, ΔIL=0.4A. The DC current rating of the inductor should be at least equal to the maximum load current plus half the ripple current to prevent core saturation (3A+0.2A). 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 requirement for the input capacitor of a buck regulator is 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 applications is sufficient. (MLCC) A 22µF MLCC or two 10uF MLCC capacitors for most applications is sufficient. 4/9 Version: A09 TS2509 3A / 500KHz PWM Buck Converter Function Descriptions (Continue) Output Capacitor Selection (EL CAP) The output capacitor is required to filter the output and provide regulator loop stability. The important capacitor parameters are; the 100KHz Equivalent Series Resistance (ESR), 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 for most applications is sufficient. 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. These items are also illustrated graphically in below. 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: A09 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: A09 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: A09 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: A09 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: A09