AP1509 150KHz, 2A PWM Buck DC/DC Converter Features General Description - Output voltage: 3.3V, 5V, 12V and adjustable output version - Adjustable version output voltage range, 1.23V to 18V+4% - 150KHz +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: 2A - SOP-8L packages - Low power standby mode - Built-in switching transistor on chip The AP1509 series are monolithic IC designed for a step-down DC/DC converter, and own the ability of driving a 2A load without additional transistor component. 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 internal compensation makes feedback control have good line and load regulation without external design. 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. If current limit function occurred and VFB is down to 0.5V below, the switching frequency will be reduced. The AP1509 series operates at a switching frequency of 150KHz thus allowing smaller sized filter components than what would be needed with lower frequency switching regulators. Other features include a guaranteed +4% 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, 12V, and an adjustable type. The packages are available in a standard 8-lead SOP-8 package. Applications - Simple High-efficiency step-down regulator - On-card switching regulators - Positive to negative converter Pin Assignments Pin Descriptions Name (Top View) VIN Output FB SD 1 2 3 4 8 7 6 5 VIN GND GND GND GND Output GND SOP-8L Description Operating voltage input Switching output Ground FB Output voltage feedback control SD ON/OFF Shutdown 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. 0.1 Nov 27, 2003 1/8 AP1509 150KHz, 2A PWM Buck DC/DC Converter Ordering Information AP1509 XX X X X Output version Package Blank : Adjustable -33 : 3.3V -50 : 5.0V -12 : 12V S: SOP-8L Lead Free Packing Blank : Tube Blank : Normal L : Lead Free Package A : Taping Block Diagram SD VIN 200mV Current Source bias 1.235V Reference 2.5V Regulator 220mV Start up + Comp _ _ Comp + Frequecy compensation _ FB + Amp _ Comp + Pre-driver 2A Switch Output 150kHz OSC. Thermal Limit Gnd Anachip Corp. www.anachip.com.tw Rev.0.1 Nov 27, 2003 2/8 AP1509 150KHz, 2A PWM Buck DC/DC Converter Absolute Maximum Ratings Symbol Parameter Rating Unit +24 V ON/OFF Pin input voltage -0.3 to +18 V VFB Feedback Pin voltage -0.3 to +18 V VOUT Output voltage to Ground VCC Supply Voltage VSD PD Power dissipation TST Storage temperature -1 V Internally limited W -65 to +150 o C o C TOP Operating temperature -40 to +125 VOP Operating voltage +4.5 to +22 V Electrical Characteristics (All Output Voltage Versions) Unless otherwise specified, VIN=12V for 3.3V, 5V, adjustable version and VIN=18V for the 12V version. ILOAD = 0.5A Symbol IB Parameter Feedback bias current FOSC Oscillator frequency FSCP Oscillator frequency short circuit protect VSAT DC ICL IL IQ ISTBY VIL VIH IH IL ΘJC ΘJA Conditions VFB=1.3V (Adjustable version only) of When current limit occurred and VFB < 0.5V, Ta=25 oC IOUT=2A Saturation voltage No outside circuit VFB=0V force driver on Max. Duty Cycle (ON) VFB=0V force driver on Min. Duty Cycle (OFF) VFB=12V force driver off Peak current Current limit No outside circuit VFB=0V force driver on Output No outside circuit Output = 0 leakage VFB=12V force driver off Output = -1 current VIN=22V Quiescent Current VFB=12V force driver off Standby Quiescent ON/OFF pin=5V Current VIN=22V 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) Junction to Thermal Resistance SOP-8L case Thermal Resistance Junction to SOP-8L With copper area of ambient 2 approximately 3 in Min. Typ. -10 127 110 150 5 15 Max. -50 -100 173 173 Unit 25 KHz nA KHz 1.4 1.25 V 1.5 100 0 % 3 A -200 -5 5 70 2.0 1.3 uA mA mA 10 150 200 0.6 uA V -0.01 -0.1 uA -1 15 o 70 o C/W C/W Anachip Corp. www.anachip.com.tw Rev.0.1 Nov 27, 2003 3/8 AP1509 150KHz, 2A PWM Buck DC/DC Converter Electrical Characteristics (Continued) Symbol AP1509-ADJ AP1509-3.3V Parameter Limit Unit 1.23 1.193/1.18 1.267/1.28 V VMIN VMAX Output Feedback 4.5V < VIN < 22V 0.2A < ILOAD < 2A VOUT programmed for 3V η Efficiency VIN = 12V, ILOAD=2A 76 Output voltage 4.75V < VIN < 22V 0.2A < ILOAD < 2A 3.3 Efficiency VIN = 12V, ILOAD=2A 78 Output voltage 7V < VIN < 22V 0.2A < ILOAD < 2A 5 Efficiency VIN = 12V, ILOAD=2A 83 Output voltage 15V < VIN < 22V 0.2A < ILOAD < 2A 12 Efficiency VIN = 15V, ILOAD = 2A 90 VOUT VOUT η AP1509-12V Typ. VFB η AP1509-5V Conditions VOUT η % 3.168/3.135 3.432/3.465 V VMIN VMAX % V VMIN VMAX 4.8/4.75 5.2/5.25 % 11.52/11.4 12.48/12.6 V VMIN VMAX % Specifications with boldface type are for full operating temperature range, the other type are for TJ=25ºC. Typical Application Circuit FB 12V 3 DC Input Vin 1 4 Cin Capacitor AP1509 -33 5 6 7 2 3.3V/2A L1 Output Output Load Inductor 8 SD Gnd Gnd Gnd Gnd D1 Schottky Diode Co Capacitor Anachip Corp. www.anachip.com.tw Rev.0.1 Nov 27, 2003 4/8 AP1509 150KHz, 2A PWM Buck DC/DC Converter Typical Performance Characteristics AP1509 Efficiency v.s. Temperature (Vin=12V,Vout=5V,Io=2A) AP1509 Efficiency v.s. Temperature (Vin=12V,Vout=3.3V,Io=2A) 81 80 79 Efficiency (%) Efficiency (%) 86 85 84 83 82 81 80 79 78 77 76 75 78 77 76 75 74 73 -50 -30 -10 10 30 50 70 90 110 130 150 -50 -30 -10 10 Temperature (TA) (°C) 30 50 70 90 110 130 150 Temperature (TA) (°C) AP1509 Saturation Voltage v.s. Temperature (Vcc=12V,Vfb=0V,VSD=0) AP1509 Switch Current Limit v.s. Temperature (Vcc=12V,Vfb=0V) 1.4 Switch Current Limit (A) 5.5 Saturation Voltage (V) 1.3 1.2 2A 1.1 1A 1 0.5A 0.9 0.8 0.7 -50 -25 0 25 50 Temperature (TA) 75 100 5 4.5 4 3.5 3 -50 125 (°C) -30 -10 10 30 50 70 90 Temperature (TA) (°C) 15 14 13 12 11 10 9 8 7 6 5 60 Supply Current (uA) Supply Current (mA) AP1509 Supply Current v.s. Temperature (Vcc=12V , No Load ,Von/off =0V(Switch ON) ,Von/off =5V(Switch OFF)) Switch ON -50 -30 -10 10 30 50 70 90 110 130 150 55 50 45 Switch OFF 40 35 30 -50 -30 -10 10 30 50 70 90 110 130 150 Temperature (TA) (°C) Temperature (TA) (°C) Anachip Corp. www.anachip.com.tw Rev.0.1 Nov 27, 2003 5/8 AP1509 150KHz, 2A PWM Buck DC/DC Converter Typical Performance Characteristics (Continued) AP1509 Threshold Voltage v.s. Temperature (Vcc=12V , Io=100mA) AP1509 ON/OFF Current v.s. ON/OFF Voltage (Vin=12V) 1.7 10 0 -10 -20 -30 -40 -50 -60 -70 -80 -90 -100 1.5 ON/OFF Current (nA) Threshold Voltage (V) 1.6 1.4 1.3 1.2 1.1 1 0.9 0.8 -50 -30 -10 10 30 50 70 0 90 110 130 150 Temperature (TA) (°C) 6 9 12 15 18 21 ON/OFF Voltage (V) AP1509 Feedback Current v.s. Temperature (Vcc=12V , Vout=5V,Vfb=1.3V) AP1509 Frequency v.s. Temperature (Vcc=12V , Io=500mA ,Vout=5V) 170 10 Feedback Current (nA) 165 Frequency (KHz) 3 160 155 150 145 140 0 -10 -20 -30 -40 -50 -50 -30 -10 10 30 50 70 90 110 130 150 -50 -30 -10 10 Temperature (TA) (°C) 30 50 70 90 110 130 150 Temperature (TA) (°C) Vout (V) AP1509 Output Voltage v.s. Temperature (Vin=12V ,Io=2A) 3.5 3.45 3.4 3.35 3.3 3.25 3.2 3.15 3.1 3.05 3 2.95 2.9 -40 -20 0 20 40 60 80 100 120 140 160 Temperature (TA) (°C) Anachip Corp. www.anachip.com.tw Rev.0.1 Nov 27, 2003 6/8 AP1509 150KHz, 2A PWM Buck DC/DC Converter Function Description Pin Functions +VIN This is the positive input supply for the IC switching regulator. A suitable input bypass capacitor must be present at this pin to minimize voltage transients and to supply the switching currents needed by the regulator. Thermal Considerations The SOP-8 package needs a heat sink under most conditions. The size of the heatsink depends on the input voltage, the output voltage, the load current and the ambient temperature. The AP1509 junction temperature rises above ambient temperature for a 2A load and different input and output voltages. The data for these curves was taken with the AP1509 (SOP-8 package) operating as a buck-switching regulator in an ambient temperature of 25oC (still air). These temperature rise numbers are all approximate and there are many factors that can affect these temperatures. Higher ambient temperatures require more heat sinking. Ground Circuit ground. Output Internal switch. The voltage at this pin switches between (+VIN – VSAT) and approximately – 0.5V, with a duty cycle of approximately VOUT / VIN. To minimize coupling to sensitive circuitry, the PC board copper area connected to this pin should be kept a minimum. For the best thermal performance, wide copper traces and generous amounts of printed circuit board copper should be used in the board layout. (Once exception to this is the output (switch) pin, which should not have large areas of copper.) Large areas of copper provide the best transfer of heat (lower thermal resistance) to the surrounding air, and moving air lowers the thermal resistance even further. Feedback Senses the regulated output voltage to complete the feedback loop. SD Allows the switching regulator circuit to be shutdown using logic level signals thus dropping the total input supply current to approximately 150uA. Pulling this pin below a threshold voltage of approximately 1.3V turns the regulator on, and pulling this pin above 1.3V (up to a maximum of 18V) shuts the regulator down. If this shutdown feature is not needed, the SD pin can be wired to the ground pin or it can be left open, in either case the regulator will be in the ON condition. Package thermal resistance and junction temperature rise numbers are all approximate, and there are many factors that will affect these numbers. Some of these factors include board size, shape, thickness, position, location, and even board temperature. Other factors are, trace width, total printed circuit copper area, copper thickness, single or double-sided, multi-layer board and the amount of solder on the board. The effectiveness of the PC board to dissipate heat also depends on the size, quantity and spacing of other components on the board, as well as whether the surrounding air is still or moving. Furthermore, some of these components such as the catch diode will add heat to the PC board and the heat can vary as the input voltage changes. For the inductor, depending on the physical size, type of core material and the DC resistance, it could either act as a heat sink taking heat away from the board, or it could add heat to the board. Anachip Corp. www.anachip.com.tw Rev.0.1 Nov 27, 2003 7/8 AP1509 150KHz, 2A PWM Buck DC/DC Converter Marking Information SOP-8L (Top view) Part Number Output Type: Blank: Adjustable 33: 3.3V 50: 5.0V 12: 12V AC 1509-XX YY WW XX Logo Blank: normal L: Lead Free Package Date Code X: Internal code WW: Nth week YY: Year 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.0.1 Nov 27, 2003 8/8