AOZ1092DIL

AOZ1092D EZBuck™ 3A Simple Buck Regulator General Description Features The AOZ1092D is a high efficiency, simple to use, 3A buck regulator. The AOZ1092D works from a 4.5V to 16V input voltage range, and provides up to 3A of continuous output current with an output voltage adjustable down to 0.8V. ● 4.5V to 16V operating input voltage range ● 50mΩ internal PFET switch for high efficiency: up to 95% Schottky diode is included Internal soft start Output voltage adjustable to 0.8V 3A continuous output current Fixed 500kHz PWM operation Cycle-by-cycle current limit Short-circuit protection Output over voltage protection Thermal shutdown Small size 4x5 DFN-8 packages The AOZ1092D comes in 4x5 DFN-8 packages and is rated over a -40°C to +85°C ambient temperature range. ● ● ● ● ● ● ● ● ● ● 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 EN L1 4.7µH U1 AOZ1092D COMP RC CC C5 AGND VOUT 3.3V LX R1 C2, C3 22µF Ceramic FB GND R2 Figure 1. 3.3V/3A Non-Synchronous Buck Regulator Rev. 1.3 February 2009 www.aosmd.com Page 1 of 16 AOZ1092D Ordering Information Part Number Ambient Temperature Range Package Environmental AOZ1092DI -40°C to +85°C DFN-8 4x5 RoHS All AOS Products are offering in packaging with Pb-free plating and compliant to RoHS standards. Please visit www.aosmd.com/web/quality/rohs_compliant.jsp for additional information. Pin Configuration VIN 1 8 LX 7 LX 6 EN 5 COMP LX PGND 2 AGND 3 GND FB 4 4x5 DFN (Top View) Pin Description Pin Number Pin Name 1 VIN 2 PGND Power ground. Electrically needs to be connected to AGND. 3 AGND Reference connection for controller section. Also used as thermal connection for controller section. Electrically needs to be connected to PGND. 4 FB 5 COMP 6 EN The enable pin is active HIGH. Connect EN pin to VIN if not used. Do not leave the EN pin floating. 7, 8 LX PWM output connection to inductor. Thermal connection for output stage. Rev. 1.3 February 2009 Pin Function Supply voltage input. When VIN rises above the UVLO threshold the device starts up. The FB pin is used to determine the output voltage via a resistor divider between the output and GND. External loop compensation pin. www.aosmd.com Page 2 of 16 AOZ1092D Block Diagram VIN UVLO & POR EN Internal +5V 5V LDO Regulator OTP + ISen – Reference & Bias Softstart Q1 ILimit + + 0.8V EAmp FB – – PWM Comp PWM Control Logic + Level Shifter + FET Driver LX D1 COMP + 0.2V 0.96V Frequency Foldback Comparator 500kHz/63kHz Oscillator – + Over Voltage Protection Comparator – AGND PGND Absolute Maximum Ratings Recommend Operating Ratings Exceeding the Absolute Maximum Ratings may damage the device. The device is not guaranteed to operate beyond the Maximum Operating Ratings. Parameter Supply Voltage (VIN) Rating Parameter 18V Supply Voltage (VIN) LX to AGND -0.7V to VIN+0.3V Output Voltage Range EN to AGND -0.3V to VIN+0.3V Ambient Temperature (TA) FB to AGND -0.3V to 6V COMP to AGND -0.3V to 6V PGND to AGND -0.3V to 0.3V Junction Temperature (TJ) +150°C Storage Temperature (TS) -65°C to +150°C Rev. 1.3 February 2009 Package Thermal Resistance DFN 4x5 (ΘJA) www.aosmd.com Rating 4.5V to 16V 0.8V to VIN -40°C to +85°C 53°C/W Page 3 of 16 AOZ1092D Electrical Characteristics TA = 25°C, VIN = VEN = 12V, VOUT = 3.3V unless otherwise specified.(3) Symbol VIN VUVLO Parameter Conditions Supply Voltage Min. Typ. 4.5 Input Under-Voltage Lockout Threshold VIN Rising 4.00 VIN Falling 3.70 Max. Units 16 V V Supply Current (Quiescent) IOUT = 0, VFB = 1.2V, VEN > 1.2V 2 3 mA IOFF Shutdown Supply Current VEN = 0V 1 10 µA VFB Feedback Voltage 0.8 0.818 V IIN IFB 0.782 Load Regulation 0.5 % Line Regulation 0.5 % Feedback Voltage Input Current 200 nA ENABLE VEN EN Input Threshold Off Threshold On Threshold VHYS 0.6 2.0 EN Input Hysteresis 100 V mV MODULATOR Frequency 400 DMAX Maximum Duty Cycle 100 DMIN Minimum Duty Cycle GVEA Error Amplifier Voltage Gain 500 V/ V GEA Error Amplifier Transconductance 200 µA / V fO 500 600 kHz % 6 % PROTECTION ILIM Current Limit 4 VPR Output Over-Voltage Protection Threshold 5 Off Threshold 960 On Threshold 840 A mV TJ Over-Temperature Shutdown Limit 150 °C tSS Soft Start Interval 2.2 ms OUTPUT STAGE High-Side Switch On-Resistance VIN = 12V 40 50 VIN = 5V 65 85 mΩ Note: 3. Specifications in BOLD indicate an ambient temperature range of -40°C to +85°C. These specifications are guaranteed by design. Rev. 1.3 February 2009 www.aosmd.com Page 4 of 16 AOZ1092D Typical Performance Characteristics Circuit of Figure 1. TA = 25°C, VIN = VEN = 12V, VOUT = 3.3V unless otherwise specified. Light Load (DCM) Operation Full Load (CCM) Operation Vin ripple 50mV/div Vin ripple 0.1V/div Vo ripple 50mV/div Vo ripple 50mV/div IL 2A/div IL 2A/div VLX 10V/div VLX 10V/div 1μs/div 1μs/div Startup to Full Load Full Load to Turn Off Vin 5V/div Vin 5V/div Vo 2V/div Vo 1V/div lin 1A/div lin 1A/div 400μs/div 1ms/div 50% to 100% Load Transient No Load to Turn Off Vin 5V/div Vo Ripple 0.1V/div Vo 1V/div lo 2A/div 1s/div 100μs/div Rev. 1.3 February 2009 lin 1A/div www.aosmd.com Page 5 of 16 AOZ1092D 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 2A/div IL 2A/div 100μs/div 1ms/div Efficiency Efficiency (VIN = 12V) vs. Load Current 100 8.0V OUTPUT Efficieny (%) 95 5.0V OUTPUT 90 3.3V OUTPUT 85 80 75 0 0.5 1.0 1.5 2.0 2.5 3.0 Load Current (A) Thermal Derating Curves Thermal derating curves for 4x5 DFN-8 package part under typical line and output voltage condition based on EVAL board. Circuit of Figure 1. 25°C ambient temperature and natural convection (air speed