AP1520

This Anachip version datasheet is replaced with Diodes Inc. datasheet AP1520 AP1520 PWM Control 2A Step-Down Converter Features - 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. General Description 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. 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. 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 Pin Assignments Pin Descriptions Name FB 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 FB 1 EN 2 AP1520 OCSET 3 VCC 4 8 7 6 5 Vss Vss Output Output EN OCSET VCC Output VSS 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 Package S: SOP-8L Packing Blank : Tube A : Taping Block Diagram Output Oscillation Circuit Vcc Reference Voltage Source with Soft Start PWM-Switched Control Circuit Thermal Shutdown + FB - VEN 100uA Vss EN 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 2/7 Rev. 1.5 Apr 10, 2006 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 -IOUT=0.1A IOUT=0.1A -VEN=0V VIN = 5V~23V IOUT=0.1 to 2A Measure waveform at SW pin Measure waveform at SW pin 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 Min. 3.6 0.784 2.5 240 10 2.0 75 0.3 Typ. 0.8 0.1 10 1 0.2 300 20 -10 90 1 110 70 92 65 Max. 23 0.816 0.5 2 0.5 360 0.8 105 2 150 100 o Unit V V µA A µA % % KHz KHz V µA µA µA ms mΩ % C/W ∆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 Efficiency Thermal Resistance Junction-to-Ambient Typical Application Circuit VIN ROCSET COCSET 3K Option CIN 680uF CVcc 0.1uF REN 100K CEN 0.1uF OCSET EN VSS D1 RB 1.3K Vcc L1 Output 22uH CC Optional FB RA 6.8K VOUT AP1520 + - C + - COUT 470uF 0.1uF Note: VOUT = VFB x (1+RA/RB) RB=0.7K~5K ohm VIN=12V, IMAX=2A 2.5V 3.3V 22uH 27uH VOUT L1 Value 5V 33uH Anachip Corp. www.anachip.com.tw 3/7 Rev. 1.5 Apr 10, 2006 This Anachip version datasheet is replaced with Diodes Inc. datasheet AP1520 AP1520 PWM Control 2A Step-Down Converter Typical Performance Characteristics AP1520 Vin v.s. Frequency (Vout=3.3V; Iout=0.2A) AP1520 Vin v.s. FB (Vout=3.3V; Iout=0.2A) 350 345 340 330 325 320 315 310 3.6 4 6 8 10 12 14 16 18 FB (V) 335 0.84 0.83 0.82 0.81 0.80 0.79 0.78 0.77 0.76 0.75 0.74 3.6 Fosc (KHz) Vin (V) 4 6 8 Vin (V) 10 12 14 16 18 3.40 3.35 AP1520 Line Regulation (Vin=12V; Iout=0.2A) Vout (V) 3.25 3.20 3.15 3.10 Vout (A) 3.30 5.10 5.09 5.08 5.07 5.06 5.05 5.04 5.03 5.02 5.01 5.00 0.0 AP1520 Load Regulation (Vin=12V) 3.6 4 6 8 Vin (V) 10 12 14 16 18 1.0 2.0 3.0 4.0 Iout (A) AP1520 Efficiency 100 90 80 Efficiency (%) 70 60 50 40 30 20 10 0 0.0 0.5 1.0 1.5 2.0 Vout:5.0V Vout:3.3V Iout (A) Anachip Corp. www.anachip.com.tw 4/7 Rev. 1.5 Apr 10, 2006 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 Oscillation open VCC OUTPUT FB open A + VCC OUTPUT FB OCSET A EN VSS - OCSET EN VSS Enable function test Feedback function test VCC + - OUTPUT FB OCSET EN VSS + - V Operation function test Anachip Corp. www.anachip.com.tw 5/7 Rev. 1.5 Apr 10, 2006 This Anachip version datasheet is replaced with Diodes Inc. datasheet AP1520 AP1520 PWM Control 2A Step-Down Converter Function Description 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. 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. 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. ILOAD × RDS(ON) = IOCSET × ROCSET See above formula for setting the current limit value. Marking Information ( Top View ) 8 5 Logo AP1520 YY WW X Part no. ID code: internal Xth week: 01~52 Year: "01" =2001 "02" =2002 1 4 ~ Anachip Corp. www.anachip.com.tw 6/7 Rev. 1.5 Apr 10, 2006 This Anachip version datasheet is replaced with Diodes Inc. datasheet AP1520 AP1520 PWM Control 2A Step-Down Converter Package Information Package Type: SOP-8L E H L VIEW "A" D 7 (4X) 0.015x45 7 (4X) A2 A A1 e B y C VIEW "A" 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 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 Anachip Corp. www.anachip.com.tw 7/7 Rev. 1.5 Apr 10, 2006