AOZ1019

AOZ1019 EZBuck™ 2A Simple Regulator General Description The AOZ1019 is a high efficiency, simple to use, 2A buck regulator. The AOZ1019 works from a 4.5V to 16V input voltage range, and provides up to 2A of continuous output current with an output voltage adjustable down to 0.8V. The AOZ1019 comes in an SO-8 package and is rated over a -40°C to +85°C ambient temperature range. Features ● ● ● ● ● ● ● ● ● ● ● ● 4.5V to 16V operating input voltage range 130mΩ internal PFET switch for high efficiency: up to 95% Internal soft start Output voltage adjustable to 0.8V 2A continuous output current Fixed 500kHz PWM operation Cycle-by-cycle current limit Short-circuit protection Under voltage lockout Output over voltage protection Thermal shutdown Small size SO-8 package Applications ● ● ● ● ● ● ● Point of load DC/DC conversion PCIe graphics cards Set top boxes DVD drives and HDD LCD panels Cable modems Telecom/Networking/Datacom equipment Typical Application VIN C1 22µF Ceramic VIN LX L1 4.7µH VOUT R2 EN AOZ1019 COMP R2 20kΩ C5 1nF C2 FB AGND PGND R3 C4, C6 22µF Ceramic Figure 1. 3.3V/2A Buck Regulator Rev. 1.0 September 2007 www.aosmd.com Page 1 of 14 AOZ1019 Ordering Information Part Number AOZ1019AI Ambient Temperature Range -40°C to +85°C Package SO-8 Environmental RoHS Pin Configuration NC VIN AGND FB 1 2 3 4 8 7 6 5 PGND LX EN COMP SO-8 (Top View) Pin Description Pin Number 1 2 3 4 5 6 7 8 Pin Name NC VIN AGND FB COMP EN LX PGND Not connected. Pin Function Supply voltage input. When VIN rises above the UVLO threshold the device starts up. Reference connection for controller section. Also used as thermal connection for controller section. Electrically needs to be connected to PGND. The FB pin is used to determine the output voltage via a resistor divider between the output and GND. External loop compensation pin. The enable pin is active high. Connect EN pin to VIN if not used. Do not leave the EN pin floating. PWM output connection to inductor. Thermal connection for output stage. Power ground. Electrically needs to be connected to AGND. Block Diagram VIN EN UVLO & POR 5V LDO Regulator Internal +5V OTP + ISen Reference & Bias – Softstart ILimit Q1 + 0.8V + EAmp – + FB – PWM Comp PWM Control Logic Level Shifter + FET Driver LX COMP 500kHz/63kHz Oscillator + 0.2V – Frequency Foldback Comparator 0.96V + – Over Voltage Protection Comparator AGND PGND Rev. 1.0 September 2007 www.aosmd.com Page 2 of 14 µ AOZ1019 Absolute Maximum Ratings Exceeding the Absolute Maximum ratings may damage the device. Recommend Operating Ratings Rating 18V -0.7V to VIN+0.3V -0.3V to VIN+0.3V -0.3V to 6V -0.3V to 6V -0.3V to +0.3V +150°C -65°C to +150°C The device is not guaranteed to operate beyond the Maximum Operating Ratings. Parameter Supply Voltage (VIN) LX to AGND EN to AGND FB to AGND COMP to AGND PGND to AGND Junction Temperature (TJ) Storage Temperature (TS) ESD Rating: Human Body Model Machine Model (1) Parameter Supply Voltage (VIN) Output Voltage Range Ambient Temperature (TA) Package Thermal Resistance SO-8 (ΘJA)(2) Rating 4.5V to 16V 0.8V to VIN -40°C to +85°C 87°C/W 2kV 200V Note: 1. Devices are inherently ESD sensitive, handling precautions are required. Human body model rating: 1.5kΩ in series with 100pF. Note: 2. The value of ΘJA is measured with the device mounted on 1-in2 FR-4 board with 2oz. Copper, in a still air environment with TA = 25°C. The value in any given application depends on the user's specific board design. TA = 25°C, VIN = VEN = 12V, VOUT = 3.3V unless otherwise specified(3) Electrical Characteristics Symbol VIN VUVLO IIN IOFF VFB Supply Voltage Parameter Input Under-Voltage Lockout Threshold Supply Current (Quiescent) Shutdown Supply Current Feedback Voltage Load Regulation Line Regulation VIN Rising VIN Falling Conditions Min. 4.5 Typ. 4.00 3.70 2 1 Max. 16 Units V V IOUT = 0, VFB = 1.2V, VEN >1.2V VEN = 0V 0.782 3 10 0.818 mA µA V % % 0.8 0.5 0.5 IFB VEN VHYS IEN fO DMAX DMIN Feedback Voltage Input Current EN Input Threshold EN Input Hysteresis EN Input Current Frequency Maximum Duty Cycle Minimum Duty Cycle Error Amplifier Voltage Gain Error Amplifier Transconductance 500 200 2.5 Off Threshold On Threshold 920 820 960 860 150 2.2 VIN = 12V VIN = 5V 97 166 400 100 500 Off Threshold On Threshold 2.0 100 200 0.6 nA V mV 1 600 6 µA kHz % % V/V µA / V MODULATOR PROTECTION ILIM VPR Current Limit Output Over-Voltage Protection Threshold Over-Temperature Shutdown Limit tSS Soft Start Interval High-Side Switch On-Resistance OUTPUT STAGE 130 200 mΩ 3.6 1000 900 A mV °C ms Note: 3. Specification in BOLD indicate an ambient temperature range of -40°C to +85°C. These specifications are guaranteed by design. Rev. 1.0 September 2007 www.aosmd.com Page 3 of 14 AOZ1019 Typical Performance Characteristics Circuit of Figure 1. TA = 25°C, VIN = VEN = 12V, VOUT = 3.3V unless otherwise specified. Light Load (DCM) Operation Vin ripple 0.1V/div Vo ripple 20mV/div IL 1A/div Full Load (CCM) Operation Vin ripple 0.1V/div Vo ripple 20mV/div IL 1A/div LX 10V/div LX 10V/div 1µs/div 1µs/div Startup to Full Load Vin 10V/div Full Load to Turnoff Vin 10V/div Vo 1V/div Vo 1V/div lin 0.5A/div lin 0.5A/div 400µs/div 400µs/div 50% to 100% Load Transient Light Load to Turnoff Vin 5V/div Vo Ripple 50mV/div Vo 1V/div lo 1A/div lin 0.5A/div 100µs/div 1s/div Rev. 1.0 September 2007 www.aosmd.com Page 4 of 14 AOZ1019 Typical Performance Characteristics (Continued) Circuit of Figure 1. TA = 25°C, VIN = VEN = 12V, VOUT = 3.3V unless otherwise specified. Short Circuit Protection Short Circuit Recovery Vo 2V/div Vo 2V/div IL 1A/div IL 1A/div 100µs/div 1ms/div AOZ1019AI Efficiency Efficiency (VIN = 12V) vs. Load Current 100 8.0V OUTPUT 95 Efficieny (%) 90 5.0V OUTPUT 3.3V OUTPUT 85 80 75 0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 Note: 4. Thermal de-rating curves for SO-8 package part under typical input and output condition based on the evaluation board. 25°C ambient temperature and natural convection (air speed