AOZ1039DI EZBuck™ 8 A Synchronous Buck Regulator General Description Features The AOZ1039DI is a high efficiency, easy to use, 8 A synchronous buck regulator. The AOZ1039DI provides up to 8 A of continuous output current with an output voltage adjustable from 1.2 V to 0.8 V when the input power rail is 12 V. For higher output voltage and/or lower input voltage, the output current should be derated according to thermal performance. z 4.5 V to 18 V operating input voltage range z Synchronous Buck: 70 mΩ internal high-side switch and 11 mΩ internal low-side switch (at 12 V) z Up to 95% efficiency z Internal soft start z Output voltage adjustable to 0.8 V z 8 A continuous output current The AOZ1039DI comes in a DFN5x6 is rated over a -40 °C to +85 °C operating ambient temperature range. z Cycle-by-cycle current limit z Pre-bias start-up z Short-circuit protection z Thermal shutdown Applications z Point of load DC/DC converters z LCD TV z Set top boxes z DVD and Blu-ray players/recorders z Cable modems Typical Application VIN = 12V C1 22µF VIN EN L1 1µH AOZ1039 R1 COMP RC CC VOUT LX C2, C3, C4 22µF FB AGND PGND R2 Figure 1. 1.05 V 8 A Synchronous Buck Regulator, Fs = 450 kHz Rev. 1.2 September 2011 www.aosmd.com Page 1 of 13 AOZ1039DI Ordering Information Part Number Ambient Temperature Range Package Environmental AOZ1039DI -40 °C to +85 °C 5x6 DFN-8 Green Product AOS Green Products use reduced levels of Halogens, and are also RoHS compliant. Please visit www.aosmd.com/web/quality/rohs_compliant.jsp for additional information. Pin Configuration PGND 1 VIN 2 AGND 3 FB 4 PAD (LX) 8 NC 7 NC 6 EN 5 COMP 5x6 DFN-8 (Top View) Pin Description Pin Number Pin Name 1 PGND 2 VIN 3 AGND 4 FB 5 COMP 6 EN Enable pin. Pull EN to logic high to enable the device. Pull EN to logic low to disable the device. If on/off control in not needed, connect EN to VIN. Do not leave EN open. 7,8 NC Not connected. Exposed pad LX Switching node. LX is the drain of the internal PFET. LX is used as the thermal pad of the power stage. Rev. 1.2 September 2011 Pin Function Power ground. PGND needs to be electrically connected to AGND. Supply voltage input. When VIN rises above the UVLO threshold and EN is logic high, the device starts up. Analog ground. AGND is the reference point for controller section. AGND needs to be electrically connected to PGND. Feedback input. The FB pin is used to set the output voltage via a resistive voltage divider between the output and AGND. External loop compensation pin. Connect a RC network between COMP and AGND to compensate the control loop. www.aosmd.com Page 2 of 13 AOZ1039DI Block Diagram VIN UVLO & POR EN Internal +5V 5V LDO Regulator OTP + ISen Softstart Ramp – Reference & Bias 0.8V + + EAmp FB Q1 ILimit – – PWM Comp PWM Control Logic + Level Shifter + FET Driver LX Q2 COMP Oscillator OVP Comp 960 mV AGND PGND Absolute Maximum Ratings Recommended Operating Conditions Exceeding the Absolute Maximum Ratings may damage the device. The device is not guaranteed to operate beyond the maximum Recommended Operating Conditions. Parameter Supply Voltage (VIN) LX to AGND LX to AGND (20 ns) EN to AGND FB, COMP to AGND PGND to AGND Rating Parameter 20 V -0.7 V to VIN+0.3 V -5 V to 22 V -0.3 V to VIN+0.3 V -0.3 V to 6 V -0.3 V to +0.3 V Junction Temperature (TJ) +150 °C Storage Temperature (TS) -65 °C to +150 °C ESD Rating (1) 2.0 kV Supply Voltage (VIN) Output Voltage Range Ambient Temperature (TA) Package Thermal Resistance 5x6 DFN-8 (ΘJA)(2) Rating 4.5 V to 18 V 0.8 V to 1.2 V -40 °C to +85 °C 40 °C/W Note: 2. The value of ΘJA is measured with the device mounted on a 1-in2 FR-4 board with 2 oz. Copper, in a still air environment with TA = 25 °C. The value in any given application depends on the user’s specific board design. Note: 1. Devices are inherently ESD sensitive, handling precautions are required. Human body model rating: 1.5 kΩ in series with 100 pF. Rev. 1.2 September 2011 www.aosmd.com Page 3 of 13 AOZ1039DI Electrical Characteristics TA = 25 °C, VIN = VEN = 12 V, VOUT = 1.1 V unless otherwise specified. Specifications in BOLD indicate a temperature range of -40 °C to +85 °C. Symbol VIN Parameter Conditions Supply Voltage Min. Typ. 4.5 Max Units 18 V VIN rising 4.1 V VIN falling 3.7 V Supply Current (Quiescent) IOUT = 0, VFB = 1.2 V, VEN > 2 V 1.6 2.5 mA IOFF Shutdown Supply Current VEN = 0 V 1 10 μA VFB Feedback Voltage TA = 25 °C 0.8 0.812 V VUVLO IIN Input Under-voltage Lockout Threshold 0.788 Load Regulation 0.1 % Line Regulation 0.02 %/V IFB Feedback Voltage Input Current VEN EN Input Threshold VHYS EN Input Hysteresis Off threshold On threshold 200 nA 0.8 V V 2 100 EN Leakage Current mV 1 μA 500 kHz MODULATOR Frequency 400 DMAX Maximum Duty Cycle 90 TMIN Controllable Minimum On Time fO 450 % 150 ns Current Sense Transconductance 8.3 A/V Error Amplifier Transconductance 200 μA / V 9 A 150 °C PROTECTION ILIM Current Limit 8.5 Over-temperature Shutdown Limit TJ rising TJ falling 100 °C Over-voltage Protection Off threshold 0.96 V Over-voltage Protection Hysteresis 100 mV tD Over-voltage Protection Delay 120 μs tSS Soft Start Time VOVP 4.5 6 7.5 ms OUTPUT STAGE High-side Switch On-resistance VIN = 12V 70 mΩ Low-side Switch On-resistance VIN = 12V 11 mΩ Rev. 1.2 September 2011 www.aosmd.com Page 4 of 13 AOZ1039DI Typical Performance Characteristics Circuit of Figure 1. TA = 25 °C, VIN = VEN = 12 V, VOUT = 1.1 V unless otherwise specified. Light Load Operation Full Load Operation Vin 50mV/div Vin 500mV/div Vo 50mV/div Vo 50mV/div IL 5A/div IL 2A/div VLX 5V/div VLX 5V/div 2µs/div 2µs/div Startup to Full Load Short Circuit Protection Vcomp 2V/div Vin 5V/div Vo 500mV/div Vo 500mV/div IL 5A/div Iin 500mA/div VLX 5V/div 2ms/div 20ms/div 3A to 6A Load Transient Short Circuity Recovery Vcomp 2V/div Vo 200mV/div Vo 500mV/div IL 5A/div Io 2A/div VLX 5V/div 100µs/div Rev. 1.2 September 2011 20ms/div www.aosmd.com Page 5 of 13 AOZ1039DI Efficiency Efficiency (VIN = 12V) vs. Load Current 90 85 1.1V OUTPUT Efficiency (%) 80 75 70 65 60 55 50 0 1 2 3 4 5 6 7 8 Load Current (A) Detailed Description The AOZ1039DI is a current-mode step down regulator with an integrated high-side PMOS switch and a low-side NMOS switch. The AOZ1039DI provides up to 8 A of continuous output current with an output voltage adjustable from 1.2 V to 0.8 V when the input power rail is 12 V. For higher output voltage and/or lower input voltage, the output current should be derated according to thermal performance. Features include enable control, power-on reset, input under voltage lockout, output over voltage protection, fixed internal soft-start and thermal shut down. Enable and Soft Start The AOZ1039DI has internal soft start feature to limit inrush current and ensure the output voltage ramps up smoothly to regulation voltage. A soft start process begins when the input voltage rises to 4.1 V and voltage on the EN pin is HIGH The EN pin of the AOZ1039DI is active high. Connect the EN pin to VIN if enable function is not used. Pulling EN to ground will disable the AOZ1039DI. Do not leave it open. The voltage on the EN pin must be above 2 V to enable the AOZ1039DI. When voltage on EN falls below 0.8 V, the AOZ1039DI is disabled. If an application circuit requires the AOZ1039DI to be disabled, an open drain or open collector circuit should be used to interface to the EN pin. Rev. 1.2 September 2011 Steady-State Operation Under heavy load steady-state conditions, the converter operates in fixed frequency and Continuous-Conduction Mode (CCM). The AOZ1039DI integrates an internal P-MOSFET as the high-side switch. Inductor current is sensed by amplifying the voltage drop across the drain to source of the high side power MOSFET. Output voltage is divided down by the external voltage divider at the FB pin. The difference of the FB pin voltage and reference voltage is amplified by the internal transconductance error amplifier. The error voltage, which shows on the COMP pin, is compared against the current signal, which is the sum of inductor current signal and ramp compensation signal, at the PWM comparator input. If the current signal is less than the error voltage, the internal high-side switch is on. The inductor current flows from the input through the inductor to the output. When the current signal exceeds the error voltage, the high-side switch is off. The inductor current is freewheeling through the internal low-side N-MOSFET switch to output. The internal adaptive FET driver guarantees no turn on overlap of both the high-side and the low-side switch. www.aosmd.com Page 6 of 13 AOZ1039DI Compared with regulators using freewheeling Schottky diodes, the AOZ1039DI uses a freewheeling NMOSFET to realize synchronous rectification. This greatly improves the converter efficiency and reduces power loss in the low-side switch. The AOZ1039DI uses a P-Channel MOSFET as the high-side switch. This saves the bootstrap capacitor normally seen in a circuit using an NMOS switch. Output Voltage Programming Output voltage can be set by feeding back the output to the FB pin by using a resistor divider network as shown in Figure 1. The resistor divider network includes R1 and R2. Usually, a design is started by picking a fixed R2 value and calculating the required R1 with equation below: R ⎞ ⎛ V O = 0.8 × ⎜ 1 + ------1-⎟ R 2⎠ ⎝ AOZ1039DID uses asymmetric Rdson of the high-side PMOS and low-side NMOS to optimize high input and the low output application. Maximum output current should be derated if the output voltage is equal to or higher than 1.5 V or if VIN is a 5 V power bus, based on thermal performance. Protection Features The AOZ1039DI has multiple protection features to prevent system circuit damage under abnormal conditions. Over Voltage Protection (OVP) The AOZ1039DI has two over voltage protection functions. First, once FB voltage is over 960 mV, the AOZ1039DI turns off both the low-side and the high-side MOSFETs to prevent either further output overshoot or excessive negative current. Over Current Protection (OCP) The sensed inductor current signal is also used for over current protection. Since the AOZ1039DI employs peak current mode control, the COMP pin voltage is proportional to the peak inductor current. The COMP pin voltage is limited to be between 0.4 V and 2.5 V internally. The peak inductor current is automatically limited cycle by cycle. When the output is shorted to ground under fault conditions, the inductor current decays very slowly during a switching cycle because the output voltage is 0 V. To prevent catastrophic failure, a secondary current limit Rev. 1.2 September 2011 is designed inside the AOZ1039DI. The measured inductor current is compared against a preset voltage which represents the current limit. When the output current is more than current limit, the high side switch will be turned off. The converter will initiate a soft start once the over-current condition is resolved. Under Voltage Lockout (UVLO) A power-on reset circuit monitors the input voltage. When the input voltage exceeds 4.1 V, the converter starts operation. When input voltage falls below 3.7 V, the converter will be shut down. Thermal Protection An internal temperature sensor monitors the junction temperature. It shuts down the internal control circuit and high side PMOS if the junction temperature exceeds 150 ºC. The regulator will restart automatically, under the control of soft-start circuit, when the junction temperature decreases to 100 ºC. Application Information The basic AOZ1039DI application circuit is show in Figure 1. Component selection is explained below. Input Capacitor The input capacitor must be connected to the VIN pin and the PGND pin of the AOZ1039DI to maintain steady input voltage and filter out the pulsing input current. The voltage rating of the input capacitor must be greater than maximum input voltage plus ripple voltage. The input ripple voltage can be approximated by equation below: IO VO ⎞ VO ⎛ -⎟ × --------ΔV IN = ----------------- × ⎜ 1 – -------f × C IN ⎝ V IN⎠ V IN Since the input current is discontinuous in a buck converter, the current stress on the input capacitor is another concern when selecting the capacitor. For a buck circuit, the RMS value of the input capacitor current can be calculated by: VO ⎛ VO ⎞ - ⎜ 1 – -------I CIN_RMS = I O × --------⎟ V IN ⎝ V IN⎠ if we let m equal the conversion ratio: VO -------- = m V IN www.aosmd.com Page 7 of 13 AOZ1039DI The relationship between the input capacitor RMS current and voltage conversion ratio is calculated and shown in Figure 2. It can be seen that when VO is half of VIN, CIN is under the worst current stress. The worst current stress on CIN is at 0.5 x IO. 0.5 reduces RMS current through the inductor and switches, which results in less conduction loss. Usually, peak to peak ripple current on the inductor is designed to be 20 % to 40 % of output current. When selecting the inductor, make sure it is able to handle the peak current without saturation even at the highest operating temperature. 0.4 The inductor takes the highest current in a buck circuit. The conduction loss on the inductor needs to be checked for thermal and efficiency requirements. ICIN_RMS(m) 0.3 IO 0.2 0.1 0 0 0.5 m 1 Output Capacitor Figure 2. ICIN vs. Voltage Conversion Ratio For reliable operation and best performance, the input capacitors must have a current rating higher than ICIN_RMS at the worst operating conditions. Ceramic capacitors are preferred as input capacitors because of their low ESR and high current rating. Depending on the application circuits, other low ESR tantalum capacitor may also be used. When selecting ceramic capacitors, X5R or X7R type dielectric ceramic capacitors should be used for their better temperature and voltage characteristics. Note that the ripple current rating from capacitor manufactures is based on a certain life time. Further de-rating may need to be considered for long term reliability. Inductor The inductor is used to supply constant current to output when it is driven by a switching voltage. For given input and output voltage, inductance and switching frequency together decide the inductor ripple current, which is: VO ⎛ VO ⎞ ΔI L = ----------- × ⎜ 1 – --------⎟ f×L ⎝ V ⎠ The output capacitor is selected based on the DC output voltage rating, output ripple voltage specification and ripple current rating. The selected output capacitor must have a higher rated voltage specification than the maximum desired output voltage including ripple. De-rating needs to be considered for long term reliability. Output ripple voltage specification is another important factor for selecting the output capacitor. In a buck converter circuit, output ripple voltage is determined by inductor value, switching frequency, output capacitor value and ESR. It can be calculated by the equation below: 1 ΔV O = ΔI L × ⎛ ESR CO + -------------------------⎞ ⎝ 8×f×C ⎠ O where, CO is output capacitor value, and ESRCO is the equivalent series resistance of the output capacitor. IN When a low ESR ceramic capacitor is used as the output capacitor, the impedance of the capacitor at the switching frequency dominates. Output ripple is mainly caused by capacitor value and inductor ripple current. The output ripple voltage calculation can be simplified to: The peak inductor current is: ΔI I Lpeak = I O + -------L2 High inductance gives low inductor ripple current but requires a larger size inductor to avoid saturation. Low ripple current reduces inductor core losses. It also Rev. 1.2 September 2011 Surface mount inductors in different shape and styles are available from Coilcraft, Elytone and Murata. Shielded inductors are small and radiate less EMI noise. However, they cost more than unshielded inductors. The choice depends on EMI requirement, price and size. 1 ΔV O = ΔI L × ------------------------8×f×C www.aosmd.com O Page 8 of 13 AOZ1039DI If the impedance of ESR at switching frequency dominates, the output ripple voltage is mainly decided by capacitor ESR and inductor ripple current. The output ripple voltage calculation can be further simplified to: ΔV O = ΔI L × ESR CO For lower output ripple voltage across the entire operating temperature range, X5R or X7R dielectric type of ceramic, or other low ESR tantalum capacitors are recommended as output capacitors. In a buck converter, output capacitor current is continuous. The RMS current of output capacitor is decided by the peak to peak inductor ripple current. It can be calculated by: ΔI L I CO_RMS = ---------12 used for the AOZ1039DI. For most cases, a series capacitor and resistor network connected to the COMP pin sets the pole-zero and is adequate for a stable highbandwidth control loop. In the AOZ1039DI, FB pin and COMP pin are the inverting input and the output of internal error amplifier. A series R and C compensation network connected to COMP provides one pole and one zero. The pole is: G EA f P2 = -----------------------------------------2π × C C × G VEA where; GEA is the error amplifier transconductance, which is 200 x 10-8 /V, A GVEA is the error amplifier voltage gain, which is 500 V/V, and CC is the compensation capacitor in Figure 1. Usually, the ripple current rating of the output capacitor is a smaller issue because of the low current stress. When the buck inductor is selected to be very small and inductor ripple current is high, the output capacitor could be overstressed. Loop Compensation The AOZ1039DI employs peak current mode control for easy of use and fast transient response. Peak current mode control eliminates the double pole effect of the output L&C filter. It also greatly simplifies the compensation loop design. With peak current mode control, the buck power stage can be simplified to be a one-pole and one-zero system in the frequency domain. The pole is dominant pole can be calculated by: 1 f P1 = ----------------------------------2π × C O × R L The zero is a ESR zero due to the output capacitor and its ESR. It is can be calculated by: The zero given by the external compensation network, capacitor CC and resistor RC, is located at: 1 f Z2 = ----------------------------------2π × C C × R C To design the compensation circuit, a target crossover frequency fC for close loop must be selected. The system crossover frequency is where control loop has unity gain. The crossover is the also called the converter bandwidth. Generally a higher bandwidth means faster response to load transient. However, the bandwidth should not be too high because of system stability concerns. When designing the compensation loop, converter stability under all line and load condition must be considered. Usually, it is recommended to set the bandwidth to be equal or less than 1/10 of switching frequency. The strategy for choosing RC and CC is to set the cross over frequency with RC and set the compensator zero with CC. Using selected crossover frequency, fC, to calculate RC: VO 2π × C C R C = f C × ---------- × ----------------------------G ×G V 1 f Z1 = -----------------------------------------------2π × C O × ESR CO FB EA CS where; where; CO is the output filter capacitor, RL is load resistor value, and fC is the desired crossover frequency. For best performance, fC is set to be about 1/10 of the switching frequency; ESRCO is the equivalent series resistance of output capacitor. VFB is 0.8V, The compensation design shapes the converter control loop transfer function to get desired gain and phase. Several different types of compensation network can be Rev. 1.2 September 2011 GEA is the error amplifier transconductance, which is 200 x 10-8 A/V, and GCS is the current sense circuit transconductance, which is 8.3 A/V www.aosmd.com Page 9 of 13 AOZ1039DI The compensation capacitor CC and resistor RC together make a zero. This zero is put somewhere close to the dominate pole fp1 but lower than 1/5 of the selected crossover frequency. CC can is selected by: 1.5 C C = ----------------------------------2π × R C × f P1 The actual junction temperature can be calculated by the power dissipation of the AOZ1039DI and the thermal impedance from junction to ambient: T junction = ( P total_loss – P inductor_loss ) × Θ JA The maximum junction temperature of the AOZ1039DI is 150 ºC, which limits the maximum load current capability. The above equation can be simplified to: The thermal performance of the AOZ1039DI is strongly affected by the PCB layout. Care should be taken by during the design process to ensure that the IC will operate under the recommended environmental conditions. CO × RL C C = --------------------RC An easy-to-use application software which helps to design and simulate the compensation loop can be found at www.aosmd.com. Thermal Management and Layout Considerations In the AOZ1039DI buck regulator circuit, high pulsing current flows through two circuit loops. The first loop starts from the input capacitors, to the VIN pin, to the LX pad, to the filter inductor, to the output capacitor and load, and then returns to the input capacitor through ground. Current flows in the first loop when the high side switch is on. The second loop starts from the inductor, to the output capacitors and load, to the low side NMOSFET. Current flows in the second loop when the low side NMOSFET is on. In PCB layout, minimizing the two area of the two loops reduces the noise of the circuit and improves efficiency. A ground plane is strongly recommended to connect the input capacitor, the output capacitor, and the PGND pin of the AOZ1039DI. In the AOZ1039DI buck regulator circuit, the major power dissipating components are the AOZ1039DI and the output inductor. The total power dissipation of the converter circuit can be measured as input power minus output power: The AOZ1039DI is a DFN 5x6 package. Several layout tips are listed below for the best electric and thermal performance. 1. The exposed pad (LX) is connected to the internal PFET and NFET drains. Connected a large copper plane to the LX pad for thermal dissipation. 2. Do not use thermal relief connection to the VIN pin and the PGND pin. Pour a maximized copper area to the PGND pin and the VIN pin to help thermal dissipation. 3. The input capacitor should be connected as close as possible to the VIN pin and the PGND pin. 4. A ground plane is preferred. If a ground plane is not used, separate PGND from AGND and connect them only at one point to avoid the PGND pin noise coupling to the AGND pin. 5. Make the current trace from LX pad to L to Co to the PGND as short as possible. 6. Pour copper plane on all unused board area and connect to stable DC nodes, like VIN, GND or VOUT. 7. Keep sensitive signal trace away from the LX pad. P total_loss = V IN × I IN – V O × I O The power dissipation of the inductor can be approximately calculated by the output current and DCR value of the inductor: P inductor_loss = IO2 × R inductor × 1.1 Rev. 1.2 September 2011 www.aosmd.com Page 10 of 13 AOZ1039DI Package Dimensions, 5x6 DFN, 8L D2 e b L θ L2 (ALL) L1 E L3 E4 E1 E3 L4 E2 D3 A1 D c A Dimensions in millimeters RECOMMENDED LAND PATTERN 4.450 0.770 0.500 2.305 0.745 3.280 0.650 0.775 0.675 Symbols Min. A 0.85 A1 0.00 0.35 b c 0.15 D D2 4.20 D3 1.23 E E1 E2 0.72 E3 0.85 E4 3.00 e L 0.47 L1 0 L2 1.375 L3 0.20 1.30 L4 0° θ Nom. 0.90 −−− 0.40 0.20 5.20 BSC 4.35 1.38 5.55 BSC 6.05 BSC 0.875 0.975 3.15 1.27 BSC 0.575 --1.475 0.30 1.40 --- Max 1.00 0.05 0.45 0.25 4.50 1.53 1.03 1.10 3.30 0.68 0.10 1.575 0.40 1.50 10 ° Dimensions in inches Symbols A A1 b c D D D3 E E1 E2 E E e L L1 L2 L3 L4 θ Min. 0.033 0.000 0.014 0.006 Nom. 0.035 −−− 0.016 0.008 0.205 BSC 0.167 0.171 0.054 0.048 0.219 BSC 0.238 BSC 0.034 0.028 0.038 0.033 0.124 0.118 0.050 BSC 0.023 0.019 0 --0.058 0.054 0.008 0.012 0.051 0.055 0° --- Max 0.039 0.002 0.018 0.010 0.175 0.060 0.041 0.043 0.130 0.027 0.004 0.062 0.016 0.059 10 ° 0.635 0.500 1.270 1.430 Notes: 1. Package body sizes exclude mold flash and gate burrs. Mold flash at the non-lead sides should be less than 6 mils each. 2. Controlling dimension is millimeter. Converted inch dimensions are not necessarily exact. Rev. 1.2 September 2011 www.aosmd.com Page 11 of 13 AOZ1039DI Tape and Reel Dimensions, 5x6 DFN, 8L Carrier Tape P1 D1 T P2 Y E1 E2 E C L B0 Y K0 D0 P0 A0 Feeding Direction UNIT: MM Package A0 B0 K0 D0 D1 DFN 5x6 (12mm) 6.30 ±0.10 5.45 ±0.10 1.30 ±0.10 1.50 Min. 1.55 ±0.05 Reel E E1 12.00 1.75 ±0.30 ±0.10 E2 P0 P1 P2 T 5.50 ±0.10 8.00 ±0.10 4.00 ±0.10 2.00 ±0.10 0.30 ±0.05 W1 S G N M K V R H W UNIT: MM Tape Size Reel Size 12 mm ø330 M N ø330.0 ø97.00 ±0.50 ±0.10 W W1 H K S G R V 13.00 ±0.30 17.40 ±1.00 ø13.0 +0.50/-0.20 10.60 2.0 ±0.5 — — — Leader/Trailer and Orientation Trailer Tape 300mm min. or 75 empty pockets Rev. 1.2 September 2011 Components Tape Orientation in Pocket www.aosmd.com Leader Tape 500mm min. or 125 empty pockets Page 12 of 13 AOZ1039DI Part Marking 5x6 DFN-8 Z1039DI FAYWLT Part Number Code Assembly Lot Code Fab & Assembly Location Year & Week Code This datasheet contains preliminary data; supplementary data may be published at a later date. Alpha & Omega Semiconductor reserves the right to make changes at any time without notice. LIFE SUPPORT POLICY ALPHA & OMEGA SEMICONDUCTOR PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS. As used herein: 1. Life support devices or systems are devices or systems which, (a) are intended for surgical implant into the body or (b) support or sustain life, and (c) whose failure to perform when properly used in accordance with instructions for use provided in the labeling, can be reasonably expected to result in a significant injury of the user. Rev. 1.2 September 2011 2. A critical component in any component of a life support, device, or system whose failure to perform can be reasonably expected to cause the failure of the life support device or system, or to affect its safety or effectiveness. www.aosmd.com Page 13 of 13