Advanced Power Electronics Corp. Preliminary APE1707 150KHz, 2A PWM Buck DC/DC Converter GENERAL DESCRIPTION The APE1707 series are monolithic IC designed for a step-down DC/DC converter, and own the ability of driving a 2A load without additional transistor. It saves board space. The external shutdown function can be controlled by logic level and then come into standby mode. The internal compensation makes feedback control having 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 occurs and VFB is down below 0.5V, the switching frequency will be reduced. The APE1707 series operates at a switching frequency of 150KHz thus allow smaller sized filter components than what would be needed with lower frequency switching regulators. The output version included fixed 3.3V, 5V, 12V, and an adjustable type. The chips are available in a standard 8-lead SOP package. FEATURES - Output voltage: 3.3V, 5V, 12V and adjustable output version1. Adjustable version output voltage range, 1.23V to 38.5V. 150KHz fixed switching frequency. Voltage mode non-synchronous PWM control. Thermal-shutdown and current-limit protection. ON/OFF shutdown control input. Short Circuit Protect (SCP). Operating voltage can be up to 40V. Output load current: 2A. SOP-8L Pb-Free packages. Low power standby mode. Built-in switching transistor on chip. Data and specifications subject to change without notice 1 20080514pre Advanced Power Electronics Corp. APE1707 BLOCK DIAGRAM EN 200mV V CC 220mV CURRENT SOURCE BIAS 1.235V 2.5V REGULATOR REFERENCE START UP + _ COMP. Current limit 150kHz OSC. _ FB COMP. + R2 + AMP _ + CONTROL + DRIVER COMP. _ COMP. 2A SWITCH R1 SW Thermal Shutdown Vss ADJ : R2=0O, R1=OPEN PIN ASSIGNMENT The package of APE1707 is SOP-8L; the pin assignment is given by: Name (Top View) Vcc SW FB EN 1 2 3 4 8 7 6 5 SOP-8L Vss Vss Vss Vss Description VCC Operating voltage input SW Switching output FB Output voltage feedback control EN ON/OFF Shutdown VSS GND pin 2 Advanced Power Electronics Corp. APE1707 ORDER INFORMATION Order Information APE1707X-XX Package Type M: SOP-8L Output Voltage 33:3.3V 50:5.0V 12: 12V Blank:ADJ MARKING INFORMATION Top Marking ADJ 1707M Y WW SSS Part number ID code: internal WW: 01~52 Year : 8 = 2008 FIX 1707M-50 Y WW SSS Part number Output Voltage ID code: internal WW: 01~52 Year : 8 = 2008 3 Advanced Power Electronics Corp. APE1707 ABSOLUTE MAXIMUM RATINGS Characteristics Symbol Rating Unit Maximum Supply Voltage VCC +45 V ON/OFF Pin Input Voltage VEN -0.3 to 40 V Feedback Pin Voltage VFB -0.3 to 12 V Output Voltage to Ground VOUT -0.8 V Power Dissipation Internally limited PD ( TJ-TA ) / θJA W Storage Temperature Range TST -65 to +150 ℃ Operating Junction Temperature Range TJ -20 to +125 ℃ Operating Supply Voltage VOP +4.5 to +40 V Thermal Resistance from Junction to case θJC 20 ℃/W Thermal Resistance from Junction to ambient θJA 60 ℃/W Note : θJA is measured with the PCB copper area(need connect to VSS pins) of approximately 1.5 in2 (Multi-layer). ELECTRICAL CHARACTERISTICS (Unless otherwise specified, Ta=25°C, VCC=12V for 3.3V, 5V, adjustable version and VCC=18V for the 12V version. ILOAD = 0.2A) Characteristics Symbol Quiescent Current IQ Feedback bias current IFB Shutdown supply Current ISD Oscillator frequency FOSC Oscillator frequency of short circuit protect FSCP Max. Duty Cycle (ON) DC Min. Duty Cycle (OFF) Current limit ICL Load Regulation( △VOUT/VOUT ) △VOUT Saturation voltage SW pin=0V SW pin=-0.8V VSA T SW pin leakage current ISW L Conditions VFB=12V force driver off VFB=1.3V (Adjustable version only) EN pin=5V VCC=40V 127 (Adjustable) When VFB<0.5V (Fixed)When < VOUT*40% VFB=0V force driver on VFB=12V force driver off Pear current, No outside circuit V FB=0V force driver on IOUT = 0.2 to 2A EN pin logic input current Low (regulator ON) High (regulator OFF) VEN=2.5V (OFF) EN pin input current IL VEN=0.5V (ON) Thermal shutdown Temp TSD Typ Max Units 4 8 mA -10 -50 nA 100 200 uA 150 50 50 100 173 KHz KHz KHz % 0 2.5 - IOUT=2A, No outside circuit VFB=0V force driver on No outside circuit VFB=12V force driver off VCC=40V force driver off VIL VIH IH EN pin logic input threshold voltage Min A 0.6 1.2 % 1.2 1.4 V -200 uA -5 2.0 mA -0.1 0.6 -10 -0.01 -1 1.3 135 V uA ℃ 4 Advanced Power Electronics Corp. APE1707 ELECTRICAL CHARACTERISTICS (Continued) version Characteristics Symbol Conditions Min Typ Max 1.193 1.23 1.267 Units ILOAD =0.2A Output Feedback V FB APE1707-ADJ VOUT programmed voltage V for 3.3V Efficiency η Output voltage V OUT Efficiency η Output voltage V OUT Efficiency η Output voltage V OUT Efficiency η APE1707-3.3V APE1707-5.0V APE1707-12V VCC = 12V, ILOAD=2A ILOAD =0.2A 79 3.20 4.85 VCC = 12V, ILOAD=2A ILOAD =0.2A VCC = 15V, ILOAD = 2A 3.40 80 VCC = 12V, ILOAD=2A ILOAD =0.2A 3.30 % 5.00 % 5.15 84 11.64 12.0 90 V V % 12.36 V % 5 Advanced Power Electronics Corp. APE1707 APPLICATION CIRCUIT (1) Adjustable Output Voltage Version VIN=12 V L1 Vout=5.0 V/2 A 1 2 47uH U1 1 2 C1 470 uF C2 0.1uF 3 4 Vcc Vss SW Vss FB Vss EN Vss R1 4.7K 8 7 D1 B 340A 6 C3 470 uF C6 0.1uF R2 1.5K 5 APE1707 (2) Adjustable Output Voltage Version With Delayed Startup VIN=12V 1 L1 1 C1 470uF C2 0.1uF 2 C4 0.1uF 3 4 R3 100k Vcc Vss SW Vss FB Vss EN ON/OFF Vout = VFB × (1 + R1 R2 Vout=2.5V/2A 2 33uH U1 Vss R1 1.8K 8 7 6 D1 B240A C3 470uF 5 C6 0.1uF R2 1.8K APE1707 ) , VFB = 1.23V, R2 = 0.47K ~ 3K Table 1 Resistor select for output voltage setting VOUT R2 R1 1.5K 4.7K 1.8K 5.6K 1.5K 2.5K 1.8K 3.0K 2.5V 1.8K 1.8K 1.8V 1.8K 0.82K 5V 3.3V L1 recommend value (IOUT=2A,) VOUT 2.5V 3.3V 5V 12V VIN=12V 33uH 33uH 47uH NA VIN=24V 33uH 33uH 47uH 68uH 6 Advanced Power Electronics Corp. APE1707 (3) Fixed Output Voltage Version VIN=12~24V Vout=3.3V/2A L1 1 33uH U1 1 2 C1 470uF C2 0.1uF 3 4 Vcc Vss SW Vss FB Vss EN 2 Vss 8 7 D1 B340A 6 C3 470uF 5 C6 0.1uF APE1707-33 (4) Inverting -5V Regulator with Delayed Startup VIN=5~20V 33uH 2A/30V 0.1uF 220uF 220uF 0.1uF 1 Vcc 2 SW 3 FB 4 EN 100k Vss 8 Vss 7 Vss Vss 6 5 100uF 0.1uF IN5400 3A/20V VOUT -5V200mA APE1707-50 7 Advanced Power Electronics Corp. APE1707 FUNCTION DESCRIPTIONS Pin Functions Vcc This is the positive input supply for the IC switching regulator. A suitable input bypass capacitor must be presented at this pin to minimize voltage transients and to supply the switching currents needed by the regulator. Vss Circuit ground. SW Internal switch. The voltage at this pin switches between (+VCC – VSAT) and approximately – 0.5V, with a duty cycle of approximately VOUT / VCC. To minimize coupling to sensitive circuitry, the PC board copper area connected to this pin should be minimized. Feedback Senses the regulated output voltage to complete the feedback loop. EN Allows the switching regulator circuit to be shutdown using logic level signals thus dropping the total input supply current to approximately 100uA. 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 Vcc) shuts the regulator down. If this shutdown feature is not needed, the EN pin can be wired to the ground pin. Thermal Considerations The SOP-8 package needs a heat sink under most conditions. The size of the heat sink depends on the input voltage, the output voltage, the load current and the ambient temperature. The APE1707 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 APE1707 (SOP-8 package) operating as a buck-switching regulator in an ambient temperature of 25℃ (still air). These temperature increments are all approximate and are affected by many factors. Higher ambient temperatures requires more heat sinker. 8 Advanced Power Electronics Corp. APE1707 FUNCTION DESCRIPTIONS (Continued) For the best thermal performance, wide copper traces and generous amounts of printed circuit board copper (need connect to the VSS pins) should be used in the board layout, (One exception is the SW(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. Package thermal resistance and junction temperature increments are all approximate. The increments are affected by a lot of factors. 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. 9 Advanced Power Electronics Corp. APE1707 TYPICAL CHARACTERISTICS Output Ripple Power on test wave (VIN=12V, VOUT=3.3V, IOUT=2A) (VIN=12V, VOUT=5V, IOUT=2A ) VOUT VIN SW SW VOUT (AC) ISW ISW Load Transient Response EN on test wave (VIN=12V, VOUT=3.3V, IOUT=0.1~2A) (VIN=12V, VOUT=5V, IOUT=2A ) VOUT VOUT (AC) VIN VOUT SW SW ISW ISW Efficiency Efficiency (VIN=12V, VOUT=3.3V) (VIN=12V, VOUT=5.0V) Vin=12V 90% 80% 80% 70% 70% 60% 60% Efficiency(%) Efficiency(%) Vin=12V 90% 50% 40% 30% 50% 40% 30% 20% 20% 10% 10% 0% 0% 0.0 0.5 1.0 Iout(A) 1.5 2.0 0.0 0.5 1.0 Iout(A) 1.5 2.0 10 ADVANCED POWER ELECTRONICS CORP. Package Outline : SO-8 D 8 7 Millimeters 6 5 E1 1 2 3 E 4 e SYMBOLS MIN NOM MAX A 1.35 1.55 1.75 A1 0.10 0.18 0.25 B 0.33 0.41 0.51 C 0.19 0.22 0.25 D 4.80 4.90 5.00 E1 3.80 3.90 4.00 E 5.80 6.15 6.50 L 0.38 0.71 1.27 θ 0 4.00 8.00 e B 1.27 TYP A A1 DETAIL A L θ 1.All Dimension Are In Millimeters. 2.Dimension Does Not Include Mold Protrusions. c DETAIL A Part Marking Information & Packing : SO-8 Part Number Package Code 1707M-XX YWWSSS Output Voltage Date Code (YWWSSS) Y：Last Digit Of The Year WW：Week SSS：Sequence 11