AP1580 PWM CONTROL 3A STEP-DOWN CONVERTER General Description Features • • • • • • • • • • AP1580 consists of step-down switching regulator with PWM control. These devices include a reference voltage source, oscillation circuit, error amplifier and internal NMOS. Input Voltage: 10V to 40V Adjustable Output Voltage from 0.8V to 0.9Vcc Duty Ratio: 0% to 90% PWM control Oscillation Frequency: 300KHz typical Short Circuit Protect Frequency: 30 KHz 2uA Maximum Standby Current Current Limit, Enable Function Thermal Shutdown Function Built-in Internal SW N-channel MOS Lead Free Finish/RoHS Compliant for Lead Free products (Note 1) Lead-Free Package: SOP-8L • AP1580 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 90%. 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 300 KHz to 30 KHz. Also, an internal compensation block is built to minimize external component count. With built-in power NMOS, a step-down switching regulator is easy to be built by adding a coil, capacitors and a diode. The high efficiency (>90%), low standby current, high input voltage (40V) and output current (3A) combining with small SOP-8L package give AP1580 unprecedented advantage in high power system applications. Applications • • • • Microprocessor Core Supply Networking Power Supply LCD MNT, TV Power Supply Telecom Power Supply Ordering Information AP 1580 X X X Package Lead - Free Packing S: SOP- 8L L : Lead Free - U : Tube -13 : Taping Note: 1. Lead-free 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) AP1580S S SOP-8L Tube Part Number Quantity Suffix 100 -U 13” Tape and Reel Part Number Quantity Suffix 2500/Tape & Reel 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. AP1580 Rev. 1 1 of 9 www.diodes.com JANUARY 2007 © Diodes Incorporated -13 AP1580 PWM CONTROL 3A STEP-DOWN CONVERTER Pin Descriptions Pin Assignments (Top View ) EN FB 1 2 Vboost Output 3 AP1580 4 Pin Name 8 7 GND GND EN 6 Vcc 5 Vcc FB Vboost Output Vcc GND SOP-8L Pin # Description H: Normal operation L: Step-down operation stopped 2 Feedback pin 3 High-side gate driver boost pin 4 Switch output pin 5、6 Signal Vcc 7、8 GND pin 1 Block Diagram Output Vcc Oscillation Circuit Driver Reference Voltage + PWM - Switched Control Circuit - FB VL Thermal Shutdown EN Vboost AP1580 Rev. 1 VEN 2 of 9 www.diodes.com GND JANUARY 2007 © Diodes Incorporated AP1580 PWM CONTROL 3A STEP-DOWN CONVERTER Absolute Maximum Ratings Symbol VCC VFB VEN Vboost VOUTPUT Top TST Caution: Parameter Rating VSS - 0.3 to VSS + 45 VSS - 0.3 to VCC VSS - 0.3 to VCC + 0.3 VOUTPUT + 5V VSS - 0.3 to VCC + 0.3 -25 to +125 -40 to +150 VCC Pin Voltage VOUT Pin Voltage EN Pin Voltage Vboost Pin Voltage Switch Pin Voltage Operating Junction Temperature Range Storage Temperature Range Unit V V V V V o C o C 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. Recommended Operating Conditions Symbol VIN IOUT TA Parameter Input Voltage Output Current Operating Ambient Temperature Min 10 0 -25 Max 40 3 85 Unit V A o C Electrical Characteristics (VIN = 12V, TA=25°C, unless otherwise specified) Symbol VFB VIN ISTBY ∆VOUT/VOUT ∆VOUT/VOUT fOSC fOSC1 DC VIH VIL ISH ISL RDS(ON) ILIMIT η θJA θJC Note: Parameter Feedback Voltage Input Voltage Standby Current Line Regulation Load Regulation Oscillation Frequency Frequency of Current Limit or Short Circuit Protect Maximum Duty Cycle Minimum Duty Cycle EN Pin Logic Input Threshold Voltage Conditions VEN =0V VIN = 10V~40V IOUT = 0.1 to 3A Measure waveform at SW pin Min. 0.780 10 240 Typ. 0.8 ±1.0 ±0.8 300 Max. 0.820 40 2 ±1.5 ±1 360 Unit V V µA % % KHz Measure waveform at SW pin - 30 - KHz 2.0 -4 - 90 0 20 -10 80 4.5 90 0.8 120 - % % - 149 - o - 13.4 - o VFB =0.5V VFB =1.0V Regulator ON Regulator OFF EN Pin Input Leakage Current Internal MOSFET RDS(ON) Current Limit Efficiency Thermal Resistance Junction-to-Ambient (Note 4) Thermal Resistance Junction-to-Case (Note 4) VIN = 12V, VOUT = 5V, IOUT = 3A V µA µA mΩ A % C/W C/W 3. The PCB layout copper area should be much greater than 10*10mm at the Vcc pins (5&6) of the AP1580, if you need large PD or low Tc&TA. The dual Vcc pins (5&6) on the SOP-8L package are internally connected. 4. Devices mounted on 2oz copper, minimum recommended pad layout, FR-4 PCB. AP1580 Rev. 1 3 of 9 www.diodes.com JANUARY 2007 © Diodes Incorporated AP1580 PWM CONTROL 3A STEP-DOWN CONVERTER Typical Application Circuit Cboost 0.1uF Vboost Vcc VIN CIN 220uF REN 100K Output AP1580 FB EN L1 33uH CC 1nF GN D RA 680 ohm + - D1 PDS 540 CEN 0.1uF VOUT =5V COUT 470uF RB 130 ohm Note: V OUT = VFB x (1+R A/RB) R B = 100 ~ 300 ohm AP1580 Rev. 1 4 of 9 www.diodes.com JANUARY 2007 © Diodes Incorporated AP1580 PWM CONTROL 3A STEP-DOWN CONVERTER Typical Performance Characteristics Load Regulation 2.00 1.50 1.60 1.20 1.20 0.90 Load Regulation (%) Line Regulation (%) Line Regulation 0.80 0.40 0.00 -0.40 9 12 15 18 21 24 27 30 33 36 39 0.60 0.30 0.00 -0.30 -0.80 0 0.5 1.5 2 2.5 3 -0.60 -1.20 -0.90 -1.60 -1.20 -2.00 -1.50 VIN (V) Iout(A) Frequency vs. Vin Iccq vs. Vin 8 350 340 330 320 310 300 290 280 270 260 250 7 6 Quiescent Current (mA) Frequency (KHz) 1 9 12 15 18 21 24 27 30 33 36 39 VIN (V) 5 4 3 2 1 0 9 12 15 18 21 24 27 VIN (V) 30 33 36 39 Efficiency 100 VIN=12V 90 80 VIN=24V Efficiency (%) 70 60 50 40 30 20 Vout=5V 10 0 0 AP1580 Rev. 1 1 Iout (A) 2 3 5 of 9 www.diodes.com JANUARY 2007 © Diodes Incorporated AP1580 PWM CONTROL 3A STEP-DOWN CONVERTER Typical Performance Characteristics (Continued) Vout Ripple (Vcc=24V; Vout=3.3V, Iout=0.5A, Vripple=19.0mV) Vout Ripple (Vcc=24V; Vout=3.3V, Iout= 3A, Vripple=35.0mV) Vripple Vripple Phase Phase Isw Isw Power Transient Wave (Iout=0~3 A, Vin=24V, Vout =3.3V) Power Transient Wave (Iout=0.1~3 A, Vin =12V, Vout =3.3V) Vout (AC) Vout (AC) Phase Phase Iout Iout AP1580 Rev. 1 6 of 9 www.diodes.com JANUARY 2007 © Diodes Incorporated AP1580 PWM CONTROL 3A STEP-DOWN CONVERTER Test Circuit Vcc A EN FB Vboost Oscillation open OUTPUT open A OUTPUT Vcc Vboost FB + open - GND Enable function test EN GND Feedback function test 33uH 0.1uF Vboost OUTPUT FB Vcc 680 ohm + - 220uF EN + GND 470uF - V 130 ohm Operation function test Function Description PWM Control The AP1580 consists of DC/DC converters that employ a pulse-width modulation (PWM) system. The PWM controller is internally clocked by a fixed 300KHz oscillator. In converters of the AP1580, the pulse width varies in a range from 0 to 90%, 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. Enable Control This input provides an electrical ON/OFF control of the power supply. Connecting this pin to ground or to any voltage less than 0.8V will completely turn OFF the regulator. The current drain from the input supply when OFF is only 2uA. C BOOST A capacitor must be connected from pin 3 to the switch output, pin 4. This capacitor boosts the gate drive to the internal MOSFET above Vin to fully turn it ON. This minimizes conduction losses in the power switch to maintain high efficiency. The recommended value for C Boost is 0.1uF. AP1580 Rev. 1 FEEDBACK This is the input to a two-stage high gain amplifier, which drivers the PWM controller. It is necessary to connect pin 2 to the actual output of the power supply to set the DC output voltage. Two external resistors are required to set the DC output voltage. For stable operation of the power supply, it is important to prevent coupling of any inductor flux to the feedback input. Current Limit The current limit threshold is set by the internal circuit that minimum switching current is 4A. The output voltage will be reduced immediately and switching frequency will be dropped to 30KHz when switching current over limit threshold. Thermal shutdown The thermal shutdown temperature depends on internal junction temperature. When junction temperature rises up to 140℃, the device will be shut down and it will be recovered after temperature reduced lower than 90℃. 7 of 9 www.diodes.com JANUARY 2007 © Diodes Incorporated AP1580 PWM CONTROL 3A STEP-DOWN CONVERTER Marking Information ( Top View ) 8 5 Logo Part No. AP1580 YY WW X 4 ~ 1 Internal code Xth week: 01~52 Year: "01" =2001 "02" =2002 Package Information ( unit: mm ) 0.08/0.25 0.254 5.79/6.20 3.70/4.10 Package Type: SOP-8L Gauge Plane Seating Plane 0.38/1.27 Detail "A" 7°~9° 0.3/0.5 1.27typ 45° 0.20typ 1.75max. 1.30/1.50 0.35max. 7°~9° Detail "A" 3.70/4.10 4.80/5.30 AP1580 Rev. 1 8 of 9 www.diodes.com JANUARY 2007 © Diodes Incorporated AP1580 PWM CONTROL 3A STEP-DOWN CONVERTER 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. AP1580 Rev. 1 9 of 9 www.diodes.com JANUARY 2007 © Diodes Incorporated