AP1530 PWM CONTROL 3A STEP-DOWN CONVERTER General Description Features • • • • • • • • • AP1530 consists of step-down switching regulator with PWM control. These devices include a reference voltage source, oscillation circuit, error amplifier, internal PMOS. Input voltage: 3.6V to 18V Output voltage: 0.8V to VCC. Duty ratio: 0% to 100% PWM control Oscillation frequency: 300KHz typ. Soft-start, Current Limit, Enable function Thermal Shutdown function Built-in internal SW P-channel MOS SOP-8L Pb-Free Package Lead Free Finish/RoHS Compliant (Note 1) AP1530 provides low-ripple power, high efficiency, and excellent transient characteristics. The PWM control circuit is able to vary the duty ratio linearly from 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 a short circuit protect function are built inside, and when OCP or SCP happens, the operation frequency will be reduced from 300KHz to 30KHz. 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 mini-package, providing such outstanding features as low current consumption. Since this converter can accommodate an input voltage up to 18V, it is also suitable for the operation via an AC adapter. Applications • • • • • • • • • PC Motherboard LCD Monitor Graphic Card DVD-Video Player Telecom Equipment ADSL Modem Printer and other Peripheral Equipment Microprocessor core supply Networking power supply Ordering Information A P 1 5 30 X X X Package Lead Free S : SOP-8L L : Lead Free Packing -U : Tube -13 : Taping Note: 1. RoHS revision 13.2.2003. Glass and High Temperature Solder Exemptions Applied, see EU Directive Annex Notes 5 and 7. Device Package Code Packaging (Note 2) AP1530S S SOP-8L Tube Part Number Quantity Suffix 100 -U 13” Tape and Reel Part Number Quantity Suffix 2500/Tape & Reel -13 Lead-free Note: 2. Pad layout as shown on Diodes Inc. suggested pad layout document AP02001, which can be found on our website at http://www.diodes.com/datasheets/ap02001.pdf. AP1530 Rev. 1 1 of 8 www.diodes.com MARCH 2007 © Diodes Incorporated AP1530 PWM CONTROL 3A STEP-DOWN CONVERTER Pin Descriptions Pin Assignments FB 1 8 Vss EN 2 7 Vss OCSET 3 6 Output VCC 4 5 Output Name FB EN AP1530 OCSET VCC Output VSS Pin Description 1 Feedback pin. Power-off pin H: Normal operation 2 (Step-down operation) L: Step-down operation stopped (All circuits deactivated) Add an external resistor to set 3 max output current. 4 IC power supply pin Switch Pin. Connect external inductor/diode here. Minimize 5、6 trace area at this pin to reduce EMI. 7、8 GND Pin Block Diagram Output Oscillation Circuit Reference Voltage Source with Soft Start Vcc + PWM-Switched Control Circuit FB - Thermal Shutdown VEN EN AP1530 Rev. 1 2 of 8 www.diodes.com 100uA Vss OCSET MARCH 2007 © Diodes Incorporated AP1530 PWM CONTROL 3A STEP-DOWN CONVERTER Absolute Maximum Ratings Symbol VCC VFB VEN VOUTPUT PD TOP TSTG Parameter VCC Pin Voltage Feedback Pin Voltage EN Pin Voltage Switch Pin Voltage Power Dissipation Operating Junction Temperature Range Storage Temperature Rating VSS - 0.3 to VSS + 20 VSS - 0.3 to VCC VSS - 0.3 to VIN + 0.3 VSS - 0.3 to VIN + 0.3 Internally limited -40 to +125 -65 to +150 Unit V V V V mW o C o C Caution: The absolute maximum ratings are rated values exceeding which the product could suffer physical damage. These values must therefore not be exceeded under any conditions. Electrical Characteristics Symbol VIN VFB IFB ISW ISSS Parameter Input Voltage Feedback Voltage Feedback Bias Current Switch Current Current Consumption During Power Off (VIN = 12V, TA=25°C, unless otherwise specified) Conditions -IOUT=0.1A IOUT=0.1A -VEN =0V ∆VOUT Line Regulation VIN=5V~18V /VOUT ∆VOUT Load Regulation IOUT=0.1 to 3A /VOUT fOSC Oscillation Frequency Measure waveform at SW pin Frequency of Current Limit or fOSC1 Measure waveform at SW pin Short Circuit Protect VSH Evaluate oscillation at SW pin EN Pin Input Voltage VSL Evaluate oscillation stop at SW pin ISH -EN Pin Input Leakage Current ISL -IOCSET OCSET Pin Bias Current -TSS Soft-Start Time -VIN=5V, VFB=0V RDSON Internal MOSFET Rdson VIN=12V, VFB=0V VIN=12V, VOUT = 5V EFFI Efficiency IOUT=3A Thermal Resistance θJA Junction-to-Ambient AP1530 Rev. 1 3 of 8 www.diodes.com Min. 3.6 0.784 3.5 Typ. 0.8 0.1 - Max. 18 0.816 0.5 - Unit V V µA A - 10 - µA - 1 2 % - 0.2 0.5 % 240 300 360 KHz 10 - - KHz 2.0 75 0.3 - 20 -10 90 2 110 70 0.8 105 5 150 100 - 92 - - 65 - V µA µA µA ms mΩ % o C/W MARCH 2007 © Diodes Incorporated AP1530 PWM CONTROL 3A STEP-DOWN CONVERTER Typical Application Circuit Vcc VIN Output ROCSET COCSET 3K Option CIN CVcc 0.1uF REN 100K AP1530 EN 22uH CC Optional VOUT RA 6.8K + FB OCSET 680uF L1 VSS D1 PDS540 C + 0.1uF - COUT 470uF RB 1.3K CEN 0.1uF Note: VOUT = VFB x (1+RA/RB) RB=0.7K~5K ohm VOUT L1 Value AP1530 Rev. 1 VIN=12V, IMAX=3A 2.5V 3.3V 15uH 18uH 4 of 8 www.diodes.com 5V 22uH MARCH 2007 © Diodes Incorporated AP1530 PWM CONTROL 3A STEP-DOWN CONVERTER Typical Performance Characteristics AP1530 Vin vs. Frequency (Vout=3.3V; Iout=0.2A) 350 345 335 FB (V) Fosc (KHz) 340 330 325 320 315 310 0 2 4 6 8 10 12 Vin (V) 14 16 18 0 3.30 Vout (A) Vout (V) 3.35 3.25 3.20 3.15 3.10 0 2 4 6 8 0.84 0.83 0.82 0.81 0.80 0.79 0.78 0.77 0.76 0.75 0.74 20 AP1530 Line Regulation (Vout=3.3V; Iout=0.2A) 3.40 AP1530 Vin vs. FB (Vout=3.3V; Iout=0.2A) 10 12 14 16 18 20 Vin (V) 2 4 6 8 10 12 14 16 18 20 Vin (V) AP1530 Load Regulation (Vin=12V) 5.10 5.09 5.08 5.07 5.06 5.05 5.04 5.03 5.02 5.01 5.00 0.0 1.0 2.0 3.0 4.0 Iout (A) Efficiency (%) AP1530 Efficiency 100 90 80 70 60 50 40 30 20 10 0 Vout:5.0V Vout:3.3V 0.0 AP1530 Rev. 1 1.0 Iout (A) 2.0 3.0 5 of 8 www.diodes.com MARCH 2007 © Diodes Incorporated AP1530 PWM CONTROL 3A STEP-DOWN CONVERTER Typical Performance Characteristics (Continued) AP1530 Vout Ripple (Vin=12V; Vout=3.3V; Iout=0.1A) AP1530 Vout Ripple (Vin=12V; Vout=3.3V; Iout=3A) Test Circuit 1K~3K VCC OUTPUT open OCSET EN A FB Oscillation open - VSS 1K~3K + - OUTPUT VCC OUTPUT FB 1K~3K + Enable function test VCC A OCSET EN VSS Feedback function test FB OCSET EN VSS + V - Operation function test Note: 3. For the Rocset selection, please refer to the formula in Function Description. AP1530 Rev. 1 6 of 8 www.diodes.com MARCH 2007 © Diodes Incorporated AP1530 PWM CONTROL 3A STEP-DOWN CONVERTER Function Description PWM Control The AP1530 consists of DC/DC converters that employ a pulse-width modulation (PWM) system. In converters of the AP1530, 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. RDS(ON) Current Limiting The current limit threshold is set by the external resistor connected from VCC supply to OCSET. The internal 100uA sink current crossing the resistor sets the voltage at the pin of OCSET. When the PWM voltage is less than the voltage at OCSET, an over-current condition is triggered. Under Voltage Lockout The under voltage lockout circuit of the AP1530 assures that the high-side MOSFET driver outputs remain in the off state whenever the supply voltage drops below 3.3V. Normal operation resumes once VCC rises above 3.5V. See above formula for setting the current limit value. ILOAD × RDS(ON) = IOCSET × ROCSET Marking Information ( Top View ) 8 5 Logo Part no. AP1530 YY WW X AP1530 Rev. 1 4 ~ 1 Internal code Xth week: 01~52 Year: "01" =2001 "02" =2002 Device Package Identification Code AP1530S SOP-8L AP1530 7 of 8 www.diodes.com MARCH 2007 © Diodes Incorporated AP1530 PWM CONTROL 3A STEP-DOWN CONVERTER Package Information ( unit: mm ) 0.254 0.08/0.25 5.79/6.20 3.70/4.10 Package Type: SOP-8L Gauge Plane Seating Plane 0.38/1.27 Detail "A" 7°~9° 0.20typ 1.75max. 1.30/1.50 0.35max. 45° 0.3/0.5 1.27typ 7°~9° Detail "A" 3.70/4.10 4.80/5.30 IMPORTANT NOTICE Diodes Incorporated and its subsidiaries reserve the right to make modifications, enhancements, improvements, corrections or other changes without further notice to any product herein. Diodes Incorporated does not assume any liability arising out of the application or use of any product described herein; neither does it convey any license under its patent rights, nor the rights of others. The user of products in such applications shall assume all risks of such use and will agree to hold Diodes Incorporated and all the companies whose products are represented on our website, harmless against all damages. LIFE SUPPORT Diodes Incorporated products are not authorized for use as critical components in life support devices or systems without the expressed written approval of the President of Diodes Incorporated. AP1530 Rev. 1 8 of 8 www.diodes.com MARCH 2007 © Diodes Incorporated