This Anachip version datasheet is replaced with Diodes Inc. datasheet AP1520 AP1520 PWM Control 2A Step-Down Converter Features General Description - Input voltage: 3.6V to 23V. - 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. AP1520 consists of step-down switching regulator with PWM control. These devices include a reference voltage source, oscillation circuit, error amplifier, internal PMOS and etc. AP1520 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. 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 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 23V, it is also suitable for the operation via an AC adapter. Pin Descriptions Pin Assignments Name FB 8 Vss 7 Vss OCSET 3 6 Output VCC 4 5 FB 1 EN 2 EN AP1520 OCSET VCC Output Output VSS Pin Description 1 Feedback pin. Power-off pin H: Normal operation (Step-down operation) 2 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 This datasheet contains new product information. Anachip Corp. reserves the rights to modify the product specification without notice. No liability is assumed as a result of the use of this product. No rights under any patent accompany the sale of the product. Rev. 1.5 Apr 10, 2006 1/7 This Anachip version datasheet is replaced with Diodes Inc. datasheet AP1520 AP1520 PWM Control 2A Step-Down Converter Ordering Information AP 1520 X X Packing Package S: SOP-8L Blank : Tube A : Taping Block Diagram Output Oscillation Circuit Reference Voltage Source with Soft Start Vcc + PWM-Switched Control Circuit FB - Thermal Shutdown VEN EN 100uA Vss OCSET Absolute Maximum Ratings Symbol VCC VFB VEN VOUTPUT PD TOPR TSTG Parameter VCC Pin Voltage Feedback Pin Voltage EN Pin Voltage Switch Pin Voltage Power Dissipation Operating Temperature Range Storage Temperature Range Rating VSS - 0.3 to VSS + 25 VSS - 0.3 to VCC VSS - 0.3 to VIN + 0.3 VSS - 0.3 to VIN + 0.3 Internally limited -20 to +125 -40 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. Anachip Corp. www.anachip.com.tw Rev. 1.5 Apr 10, 2006 2/7 This Anachip version datasheet is replaced with Diodes Inc. datasheet AP1520 AP1520 PWM Control 2A Step-Down Converter Electrical Characteristics (VIN = 12V, Ta=25°C, unless otherwise specified) Symbol VIN VFB IFB ISW ISSS Parameter Input Voltage Feedback Voltage Feedback Bias Current Switch Current Current Consumption During Power off Conditions ∆VOUT Line Regulation /VOUT ∆VOUT Load Regulation /VOUT fOSC Oscillation Frequency Frequency of Current Limit fOSC1 or Short Circuit Protect VSH EN Pin Input Voltage VSL ISH EN Pin Input Leakage Current ISL IOCSET OCSET Pin Bias Current TSS Soft-Start Time RDSON Internal MOSFET Rdson EFFI θJA Min. 3.6 0.784 2.5 Typ. 0.8 0.1 - Max. 23 0.816 0.5 - Unit V V µA A VEN=0V - 10 - µA VIN = 5V~23V - 1 2 % IOUT=0.1 to 2A - 0.2 0.5 % Measure waveform at SW pin 240 300 360 KHz Measure waveform at SW pin 10 - - KHz Evaluate oscillation at SW pin Evaluate oscillation stop at SW pin ----VIN=5V, VFB=0V VIN=12V, VFB=0V VIN = 12V, VOUT = 5V IOUT = 2A 2.0 75 0.3 - 20 -10 90 1 110 70 0.8 105 2 150 100 - 92 - - 65 - -IOUT=0.1A IOUT=0.1A -- Efficiency Thermal Resistance Junction-to-Ambient V µA µA µA ms mΩ % o C/W Typical Application Circuit L1 Vcc VIN Output ROCSET COCSET 3K Option CIN CC Optional AP1520 CVcc 0.1uF REN 100K EN VOUT RA 6.8K + FB OCSET 680uF 22uH VSS D1 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 VIN=12V, IMAX=2A 2.5V 3.3V 22uH 27uH Anachip Corp. www.anachip.com.tw 5V 33uH Rev. 1.5 Apr 10, 2006 3/7 This Anachip version datasheet is replaced with Diodes Inc. datasheet AP1520 AP1520 PWM Control 2A Step-Down Converter Typical Performance Characteristics 350 AP1520 Vin v.s. Frequency (Vout=3.3V; Iout=0.2A) 345 335 FB (V) Fosc (KHz) 340 330 325 320 315 310 3.6 4 6 8 10 Vin (V) 12 14 16 3.6 3.30 Vout (A) Vout (V) 3.35 3.25 3.20 3.15 3.10 3.6 4 6 8 10 Vin (V) 12 14 16 0.84 0.83 0.82 0.81 0.80 0.79 0.78 0.77 0.76 0.75 0.74 18 AP1520 Line Regulation (Vin=12V; Iout=0.2A) 3.40 AP1520 Vin v.s. FB (Vout=3.3V; Iout=0.2A) 6 8 10 Vin (V) 12 14 16 18 AP1520 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 18 4 1.0 2.0 3.0 4.0 Iout (A) AP1520 Efficiency 100 90 Efficiency (%) 80 70 60 50 40 30 Vout:5.0V 20 Vout:3.3V 10 0 0.0 0.5 1.0 1.5 2.0 Iout (A) Anachip Corp. www.anachip.com.tw Rev. 1.5 Apr 10, 2006 4/7 This Anachip version datasheet is replaced with Diodes Inc. datasheet AP1520 AP1520 PWM Control 2A Step-Down Converter Typical Performance Characteristics (Continued) AP1520 Vout Ripple (Vin=12V; Vout=3.3V; Iout=0.1A) AP1520 Vout Ripple (Vin=12V; Vout=3.3V; Iout=2A) Test Circuit VCC OUTPUT FB Oscillation open open OCSET A EN + VSS - Enable function test VCC + - A OUTPUT VCC OUTPUT OCSET EN FB VSS Feedback function test FB OCSET EN VSS V + - Operation function test Anachip Corp. www.anachip.com.tw Rev. 1.5 Apr 10, 2006 5/7 This Anachip version datasheet is replaced with Diodes Inc. datasheet AP1520 AP1520 PWM Control 2A Step-Down Converter Function Description RDS(ON) Current Limiting The current limit threshold is setting by the external resistor connecting 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. PWM Control The AP1520 consists of DC/DC converters that employ a pulse-width modulation (PWM) system. In converters of the AP1520, 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. ILOAD × RDS(ON) = IOCSET × ROCSET See above formula for setting the current limit value. Under Voltage Lockout The under voltage lockout circuit of the AP1520 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. Marking Information ( Top View ) 8 5 Logo AP1520 Part no. YY WW X 4 Anachip Corp. www.anachip.com.tw ~ 1 ID code: internal Xth week: 01~52 Year: "01" =2001 "02" =2002 Rev. 1.5 Apr 10, 2006 6/7 This Anachip version datasheet is replaced with Diodes Inc. datasheet AP1520 AP1520 PWM Control 2A Step-Down Converter Package Information H E Package Type: SOP-8L L VIEW "A" D 0.015x45 7 (4X) e B A1 C A A2 7 (4X) VIEW "A" y Symbol A A1 A2 B C D E e H L y θ Dimensions In Millimeters Min. Nom. Max. 1.40 1.60 1.75 0.10 0.25 1.30 1.45 1.50 0.33 0.41 0.51 0.19 0.20 0.25 4.80 5.05 5.30 3.70 3.90 4.10 1.27 5.79 5.99 6.20 0.38 0.71 1.27 0.10 0O 8O Anachip Corp. www.anachip.com.tw Dimensions In Inches Min. Nom. Max. 0.055 0.063 0.069 0.040 0.100 0.051 0.057 0.059 0.013 0.016 0.020 0.0075 0.008 0.010 0.189 0.199 0.209 0.146 0.154 0.161 0.050 0.228 0.236 0.244 0.015 0.028 0.050 0.004 0O 8O Rev. 1.5 Apr 10, 2006 7/7