AP1503 300Khz, 2.5A PWM Buck DC/DC Converter Features General Description - Output voltage: 3.3V - 300KHz +15% fixed switching frequency - Voltage mode non-synchronous PWM control - Thermal-shutdown and current-limit protection - ON/OFF shutdown control input - Operating voltage can be up to 22V - Output load current: 2.5A - SOP-7L packages - Low power standby mode - Built-in switching transistor on chip The AP1503 series are monolithic ICs designed for step-down DC/DC converters, and own the ability of driving a 2.5A load without additional transistor components. Due to reducing the number of external component, the board space can be saved easily. The external shutdown function can be controlled by logic level and then come into standby mode. The external compensation makes feedback control have good line and load regulation. Regarding protected function, thermal shutdown is to prevent over temperature operating from damage, and current limit is against over current operating of the output switch. The AP1503 series operates at a switching frequency of 300KHz thus allowing smaller sized filter components than what would be needed with lower frequency switching regulators. Other features include a guaranteed +2% tolerance on output voltage under specified input voltage and output load conditions, and +15% on the oscillator frequency. The output version included fixed 3.3V, 5V. The packages are available in a standard SOP-7 lead package. Applications - Simple High-efficiency step-down regulator - On-card switching regulators - Positive to negative converter - DSL Modems - Portable Computers - Regulated Wall Adapters - Distributed Power Pin Assignment Pin Descriptions Name SOP7 with Heat Sink VIN 1 VB 2 SD 3 FB 4 7 VO 6 GND VIN Operating voltage input VB Boost pin SD ON/OFF Shutdown FB Output voltage feedback control COMP 5 COMP Description GND VO Compensation pin Ground Switching output 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 1.0 Sep. 29, 2004 1/5 AP1503 300Khz, 2.5A PWM Buck DC/DC Converter Ordering Information AP1503 XX X X X Output version -33 : 3.3V Package Lead Free Packing S : SOP-7L Blank : Normal L : Lead Free Package Blank : Tube A : Taping Block Diagram SD VIN 200mV Current Source bias 1.235V Reference 2.5V Regulator 220mV Start up + Comp _ _ Comp + VB + Amp _ Frequecy compensation _ FB Comp + Pre-driver 3A Switch VO 300kHz OSC. Thermal Shutdown GND COMP Anachip Corp. www.anachip.com.tw Rev 1.0 Sep. 29, 2004 2/5 AP1503 300Khz, 2.5A PWM Buck DC/DC Converter Absolute Maximum Ratings Symbol VCC VSD VFB VOUT PD TST TOP VOP Parameter Supply Voltage ON/OFF Pin input voltage Feedback Pin voltage Output voltage to Ground Power dissipation Storage temperature Operating temperature Operating voltage Rating +26 -0.3 to +25 -0.3 to +25 -1 Internally limited -65 to +150 -40 to +125 +7 to +40 Unit V V V V W o C o C V Electrical Characteristics (All Output Voltage Versions) Unless otherwise specified, VIN=12V for 3.3V, 5V, ILOAD = 0.5A Symbol Parameter FOSC Oscillator frequency VSAT Saturation voltage DC Max. Duty Cycle (ON) Min. Duty cycle (OFF) ICL Current limit IL VC VB IB IQ ISTBY VIL VIH IH IL ΘJC ΘJA Output leakage Output = -1 current Output = 0 Conditions Min. Typ. Max. 255 300 345 230 ISW=2A VB=VIN+2.5V. VFB=0V force driver on VFB=6V force driver off Peak current No outside circuit VFB=0 force driver on no outside circuit VFB=6V force driver off VIN=24V COMP Min SW threshold Duty Cycle=0%,FB=3.5V 2A ISW threshold Min VB above switch ISW=2A ISW=1A Boost current ISW=2A Quiescent Current VFB=6 force driver off Standby Quiescent ON/OFF pin=5V Current VIN=24V Low (regulator ON) ON/OFF pin logic input threshold voltage High (regulator OFF) ON/OFF pin logic input VLOGIC=2.5V (OFF) current ON/OFF pin input current VLOGIC=0.5V (ON) Thermal Resistance SOP-7L Junction to case Thermal Resistance Junction to With copper area of SOP-7L 2 ambient approximately 0.5 in Anachip Corp. www.anachip.com.tw 0.4 360 0.5 0.6 Unit KHz V 90 0 3 3.25 0.04 0.8 2.6 120 130 5 80 2.0 1.3 % 3.5 A 4 -1 uA -1 mA V 3 V mA 140 10 150 200 0.6 mA uA V -0.1 -1 uA 20 o 50 o C/W C/W Rev 1.0 Sep. 29, 2004 3/5 AP1503 300Khz, 2.5A PWM Buck DC/DC Converter Electrical Characteristics (Continued) Symbol Parameter Conditions Typ. Limit Unit VOUT Output voltage 7V < VIN < 24V 0.2A < ILOAD < 2.5A 3.3 3.23/3.2 3.37/3.4 V VMIN VMAX η Efficiency VIN = 12V, ILOAD=2A 79 AP1503-3.3V % Specifications with boldface type are for full operating temperature range, the other type are for TJ=25ºC. Typical Application Circuit FB 7V DC Input Vin AP1503 -33 1 5 3 Cin Capacitor VB 2 4 SD 7 CB VO D2 3.3V/2.5A Schottky Diode Output Load L1 Inductor 6 COMP GND D1 Schottky Diode Co Capacitor CC Anachip Corp. www.anachip.com.tw Rev 1.0 Sep. 29, 2004 4/5 AP1503 300Khz, 2.5A PWM Buck DC/DC Converter Marking Information ( Top View ) 7 5 Logo Output Type 33 : 3.3V AP1503 XX Blank: normal L: Lead Free Package YY WW X X 1 ID code: internal Xth week: 01~52 Year: "01" = 2001 "02" = 2002 4 ~ Package Information Package Type: SOP-7L C2 C3 B1 B2 A E C1 C e D β F Symbol A B1 B2 C C1 C2 C3 D E e F β Dimensions In Millimeters Min. 5.79 3.83 3.78 4.80 1.57 0.32 1.17 0.19 0.48 1.35 Nom. 5.99 3.91 3.86 4.87 1.67 0.4 1.27 0.22 1.04REF 0.68 1.45 7o Dimensions In Inches Max. 6.19 3.99 3.94 4.94 1.77 0.48 1.37 0.25 Min. 0.228 0.151 0.149 0.189 0.062 0.013 0.046 0.007 0.88 1.55 0.019 0.053 Anachip Corp. www.anachip.com.tw Nom. 0.236 0.154 0.152 0.192 0.066 0.016 0.050 0.009 0.041REF 0.027 0.057 7o Max. 0.244 0.157 0.155 0.194 0.070 0.019 0.054 0.010 0.035 0.061 Rev 1.0 Sep. 29, 2004 5/5