AOZ1024D EZBuck™ 4A Synchronous Buck Regulator General Description Features The AOZ1024D is a synchronous high efficiency, simple to use, 4A buck regulator. The AOZ1024D works from a 4.5V to 16V input voltage range, and provides up to 4A of continuous output current with an output voltage adjustable down to 0.8V. ● ● ● ● The AOZ1024D comes in a DFN 5 x 4 package and is rated over a -40°C to +85°C ambient temperature range. ● ● ● ● ● ● ● ● ● 4.5V to 16V operating input voltage range Synchronous rectification: 100mΩ internal high-side switch and 20mΩ internal low-side switch High efficiency: up to 95% Internal soft start 1.5% initial output accuracy Output voltage adjustable to 0.8V 4A continuous output current Fixed 500kHz PWM operation Cycle-by-cycle current limit Pre-bias start-up Short-circuit protection Thermal shutdown Small size DFN 5 x 4 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 L1 4.7µH EN AOZ1024D VOUT LX R1 COMP RC CC FB AGND PGND C2, C3 22µF Ceramic R2 Figure 1. 3.3V/4A Synchronous Buck Regulator Rev. 1.1 November 2007 www.aosmd.com Page 1 of 16 AOZ1024D Ordering Information Part Number Ambient Temperature Range Package Environmental AOZ1024DI -40°C to +85°C DFN-8 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 PGND 1 8 LX 7 LX 6 EN 5 COMP LX VIN 2 AGND 3 GND FB 4 5 x 4 DFN (Top Thru View) Pin Description Pin Number Pin Name 1 PGND 2 VIN 3 AGND Reference connection for controller section. Also used as thermal connection for controller section. Electrically needs to be connected to PGND. 4 FB The FB pin is used to determine the output voltage via a resistor divider between the output and GND. 5 COMP 6 EN The enable pin is active high. Connect in to VIN if not used and do not leave it open. 7, 8 LX PWM output connection to inductor. Rev. 1.1 November 2007 Pin Function Power ground. Electrically needs to be connected to AGND. Supply voltage input. When VIN rises above the UVLO threshold the device starts up. External loop compensation pin. www.aosmd.com Page 2 of 16 AOZ1024D 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 + COMP + 0.2V Frequency Foldback Comparator Level Shifter + FET Driver LX Q2 500kHz/68kHz Oscillator – 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. Rating Parameter Parameter Rating Supply Voltage (VIN) 18V Supply Voltage (VIN) LX to AGND -0.7V to VIN+0.3V Output Voltage Range 0.8V to VIN EN to AGND -0.3V to VIN+0.3V Ambient Temperature (TA) -40°C to +85°C FB to AGND -0.3V to 6V 50°C/W COMP to AGND -0.3V to 6V Package Thermal Resistance DFN-8 (ΘJA)(2) PGND to AGND -0.3V to +0.3V PGOOD to AGND -0.3V to 6V Junction Temperature (TJ) +150°C Storage Temperature (TS) -65°C to +150°C (1) ESD Rating 4.5V to 16V 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. 2.0kV Note: 1. Devices are inherently ESD sensitive, handling precautions are required. Human body model rating: 1.5kΩ in series with 100pF. Rev. 1.1 November 2007 www.aosmd.com Page 3 of 16 uµ AOZ1024D Electrical Characteristics TA = 25°C, VIN = VEN = 12V, VOUT = 3.3V unless otherwise specified(3) Symbol VIN VUVLO IIN Parameter Conditions Supply Voltage Typ. 4.5 Max. Units 16 V Input Under-Voltage Lockout Threshold VIN Rising VIN Falling 4.1 3.7 1.6 2.5 mA 3 20 uA 0.8 0.812 Supply Current (Quiescent) IOUT = 0, VFB = 1.2V, VEN > 1.2V IOFF Shutdown Supply Current VEN = 0V VFB Feedback Voltage 0.788 V V Load Regulation 0.5 % Line Regulation 1 % IFB Feedback Voltage Input Current VEN EN Input Threshold VHYS Min. 200 Off Threshold On Threshold 0.6 2 EN Input Hysteresis 100 nA V mV MODULATOR fO Frequency 350 DMAX Maximum Duty Cycle 100 DMIN Minimum Duty Cycle 500 600 kHz % 6 % Error Amplifier Voltage Gain 500 V/ V Error Amplifier Transconductance 200 µA / V PROTECTION ILIM Current Limit Over-Temperature Shutdown Limit tSS 5.0 TJ Rising TJ Falling Soft Start Interval 6.0 150 100 3 A °C 5 7 ms OUTPUT STAGE High-Side Switch On-Resistance VIN = 12V VIN = 5V 97 166 130 200 mΩ Low-Side Switch On-Resistance VIN = 12V VIN = 5V 18 30 23 36 mΩ Note: 3. Specification in BOLD indicate an ambient temperature range of -40°C to +85°C. These specifications are guaranteed by design. Rev. 1.1 November 2007 www.aosmd.com Page 4 of 16 AOZ1024D Typical Performance Characteristics Circuit of Figure 1. TA = 25°C, VIN = VEN = 12V, VOUT = 3.3V unless otherwise specified. Light Load Operation Full Load (CCM) Operation Vin ripple 0.1V/div Vin ripple 0.1V/div Vo ripple 20mV/div Vo ripple 20mV/div IL 1A/div IL 1A/div VLX 10V/div VLX 10V/div 1µs/div 1µs/div Startup to Full Load Short Circuit Protection VIN 10V/div LX 10V/div Vo 2V/div Vo 2V/div lL 5A/div lin 1A/div 1ms/div 100µs/div 50% to 100% Load Transient Short Circuit Recovery Vo Ripple 200mV/div Vo 2V/div lo 2A/div IL 5A/div 100µs/div Rev. 1.1 November 2007 2ms/div www.aosmd.com Page 5 of 16 AOZ1024D Efficiency AOZ1024D Efficiency Efficiency (VIN = 12V) vs. Load Current Efficieny (%) 100 95 5V OUTPUT 90 3.3V OUTPUT 1.8V OUTPUT 85 1.2V OUTPUT 80 75 70 65 0 0.5 1 1.5 2 2.5 3 3.5 4 Load Current (A) Thermal Derating Curves For DFN package part under typical line and output voltage condition. Circuit of Figure 1. 25°C ambient temperature and natural convection (air speed<50LFM) unless otherwise specified. Derating Curve at 5V/6V Input Derating Curve at 12V Input 5 4.4 1.2V OUTPUT 4.2 1.8V Output Current (IO) Output Current (IO) 4 3 3.3V OUTPUT 2 1 1.2V, 1.8V OUTPUT 4.0 3.3V 3.8 5V OUTPUT 3.6 0 3.4 25 35 45 55 65 75 85 Ambient Temperature (TA) Rev. 1.1 November 2007 25 35 45 55 65 75 85 Ambient Temperature (TA) www.aosmd.com Page 6 of 16 AOZ1024D Detailed Description The AOZ1024D is a current-mode step down regulator with integrated high-side PMOS switch and a low-side NMOS switch. It operates from a 4.5V to 16V input voltage range and supplies up to 4A of load current. The duty cycle can be adjusted from 6% to 100% allowing a wide range of output voltage. Features include enable control, Power-On Reset, input under voltage lockout, output over voltage protection, active high power good state, fixed internal soft-start, and thermal shut down. switch to output. The internal adaptive FET driver guarantees no turn on overlap of both high-side and low-side switch. The AOZ1024D is available in a DFN 5x4 package. The AOZ1024D uses a P-Channel MOSFET as the high-side switch. It saves the bootstrap capacitor normally seen in a circuit which is using an NMOS switch. It allows 100% turn-on of the high-side switch to achieve linear regulation mode of operation. The minimum voltage drop from VIN to VO is the load current x DC resistance of MOSFET + DC resistance of buck inductor. It can be calculated by equation below: Enable and Soft Start The AOZ1024D has internal soft start feature to limit in-rush current and ensure the output voltage ramps up smoothly to regulation voltage. A soft start process begins when the input voltage rises to 4.1V and voltage on the EN pin is HIGH. In the soft start process, the output voltage is typically ramped to regulation voltage in 5ms. The 4ms soft start time is set internally. Compared with regulators using freewheeling Schottky diodes, the AOZ1024D uses freewheeling NMOSFET to realize synchronous rectification. It greatly improves the converter efficiency and reduces power loss in the low-side switch. V O _MAX = V IN – I O × R DSON where; The EN pin of the AOZ1024D is active HIGH. Connect the EN pin to VIN if enable function is not used. Pulling EN to ground will disable the AOZ1024D. Do not leave it open. The voltage on EN pin must be above 2V to enable the AOZ1024D. When voltage on the EN pin falls below 0.6V, the AOZ1024D is disabled. If an application circuit requires the AOZ1024D to be disabled, an open drain or open collector circuit should be used to interface to the EN pin. Steady-State Operation Under steady-state conditions, the converter operates in fixed frequency and Continuous-Conduction Mode (CCM). The AOZ1024D 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 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 sum of inductor current signal and ramp compensation signal, at 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 Rev. 1.1 November 2007 VO_MAX is the maximum output voltage, VIN is the input voltage from 4.5V to 16V, IO is the output current from 0A to 4A, and RDS(ON) is the on resistance of internal MOSFET, the value is between 97mΩ and 200mΩ depending on input voltage and junction temperature. Switching Frequency The AOZ1024D switching frequency is fixed and set by an internal oscillator. The practical switching frequency could range from 350kHz to 600kHz due to device variation. Output Voltage Programming Output voltage can be set by feeding back the output to the FB pin by using a resistor divider network (see 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 Some standard values of R1 and R2 for the most commonly used output voltage values are listed in Table 1. www.aosmd.com Page 7 of 16 AOZ1024D Table 1. 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°C. The regulator will restart automatically under the control of soft-start circuit when the junction temperature decreases to 100ºC. VO (V) R1 (kΩ) R2 (kΩ) 0.8 1.0 Open 1.2 4.99 10 1.5 10 11.5 1.8 12.7 10.2 2.5 21.5 10 Application Information 3.3 31.6 10 5.0 52.3 10 The basic AOZ1024 application circuit is show in Figure 1. Component selection is explained below. The combination of R1 and R2 should be large enough to avoid drawing excessive current from the output, which will cause power loss. Since the switch duty cycle can be as high as 100%, the maximum output voltage can be set as high as the input voltage minus the voltage drop on upper PMOS and inductor. Protection Features The AOZ1024D has multiple protection features to prevent system circuit damage under abnormal conditions. Input capacitor The input capacitor must be connected to the VIN pin and PGND pin of AOZ1024D to maintain steady input voltage and filter out the pulsing input current. The voltage rating of 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 ∆V IN = ------------------ × 1 – ---------- × ---------f × C IN V IN V IN Over Current Protection (OCP) The sensed inductor current signal is also used for over current protection. Since the AOZ1024D 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 0.4V and 2.5V internally. The peak inductor current is automatically limited cycle by cycle. 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 input capacitor current can be calculated by: When the output is shorted to ground under fault conditions, the inductor current decays very slowly during a switching cycle because of VO = 0V. To prevent catastrophic failure, a secondary current limit is designed inside the AOZ1024D. The measured inductor current is compared against a preset voltage which represents the current limit, between 5.0A and 6.0A. 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. if we let m equal the conversion ratio: VO VO I CIN _RMS = I O × --------- 1 – --------- V IN V IN VO ---------- = m V IN The relation between the input capacitor RMS current and voltage conversion ratio is calculated and shown in Figure 2 on the next page. 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 0.5 x IO. Power-On Reset (POR) A power-on reset circuit monitors the input voltage. When the input voltage exceeds 4.1V, the converter starts operation. When input voltage falls below 3.7V, the converter will be shut down. Rev. 1.1 November 2007 www.aosmd.com Page 8 of 16 AOZ1024D The inductor takes the highest current in a buck circuit. The conduction loss on inductor need to be checked for thermal and efficiency requirements. 0.5 0.4 Surface mount inductors in different shape and styles are available from Coilcraft, Elytone and Murata. Shielded inductors are small and radiate less EMI noise, but they cost more than unshielded inductors. The choice depends on EMI requirement, price, and size. ICIN_RMS(m) 0.3 IO 0.2 0.1 0 0 0.5 m 1 Figure 2. ICIN vs. Voltage Conversion Ratio For reliable operation and best performance, the input capacitors must have current rating higher than ICIN_RMS at worst operating conditions. Ceramic capacitors are preferred for 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 are based on certain amount of life time. Further de-rating may be necessary in practical design. 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 ∆I L = ----------- × 1 – --------- f ×L V IN 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 ∆V O = ∆I L × ES R CO + --------------------------- 8 × f × C O where, CO is output capacitor value, and ESRCO is the equivalent series resistance of the output capacitor. 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: ∆I I Lpeak = I O + --------L2 1 ∆V O = ∆I L × --------------------------8×f ×C O 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 reduces RMS current through inductor and switches, which results in less conduction loss. Usually, peak to peak ripple current on inductor is designed to be 20–30% 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. Rev. 1.1 November 2007 Output Capacitor The output capacitor is selected based on the DC output voltage rating, output ripple voltage specification and ripple current rating. 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: ∆V O = ∆I L × ES R 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 to be used as output capacitors. www.aosmd.com Page 9 of 16 AOZ1024D 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: where; GEA is the error amplifier transconductance, which is 200 x 10-6 A/V, GVEA is the error amplifier voltage gain, which is 500 V/V, and ∆I L I CO _RMS = ---------12 Cc is 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, output capacitor could be overstressed. 1 f Z 2 = ------------------------------------2π × C C × R C Loop Compensation The AOZ1024D employs peak current mode control for easy use and fast transient response. Peak current mode control eliminates the double pole effect of the output L&C filter. It 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 frequency domain. The pole is dominant pole can be calculated by: 1 f P 1 = -----------------------------------2π × C O × R L The zero given by the external compensation network, capacitor Cc and resistor Rc, is located at: 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 concern. 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 AOZ1024D operates at a frequency range from 350kHz to 600kHz. It is recommended to choose a crossover frequency equal or less than 40kHz. f C = 40kHz The zero is a ESR zero due to output capacitor and its ESR. It is can be calculated by: 1 f Z 1 = -------------------------------------------------2π × C O × ESR CO 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 where; CO is the output filter capacitor, FB RL is load resistor value, and ESRCO is the equivalent series resistance of output capacitor. EA CS where; fC is the desired crossover frequency. For best performance, fC is set to be about 1/10 of the switching frequency; The compensation design is actually to shape the converter control loop transfer function to get desired gain and phase. Several different types of compensation network can be used for the AOZ1024D. For most cases, a series capacitor and resistor network connected to the COMP pin sets the pole-zero and is adequate for a stable high-bandwidth control loop. GEA is the error amplifier transconductance, which is 200 x 10-6 A/V, and In the AOZ1024D, 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: 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 selected crossover frequency. C2 can is selected by: G EA f P 2 = ----------------------------------------2π× C c × G VEA Rev. 1.1 November 2007 VFB is 0.8V, GCS is the current sense circuit transconductance, which is 6.68 A/V. 1.5 C C = ------------------------------------2π × R C × f P 1 www.aosmd.com Page 10 of 16 AOZ1024D The previous equation can also be simplified to: The maximum junction temperature of AOZ1024D is 150°C, which limits the maximum load current capability. Please see the thermal de-rating curves for maximum load current of the AOZ1024D under different ambient temperature. 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 Consideration In the AOZ1024D 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 pins, to the filter inductor, to the output capacitor and load, and then return to the input capacitor through ground. Current flows in the first loop when the high side switch is on. The second loop starts from inductor, to the output capacitors and load, to the lowside NMOSFET. Current flows in the second loop when the lowside NMOSFET is on. In PCB layout, minimizing the two loops area reduces the noise of this circuit and improves efficiency. A ground plane is strongly recommended to connect input capacitor, output capacitor, and PGND pin of the AOZ1024D. In the AOZ1024D buck regulator circuit, the major power dissipating components are the AOZ1024D and the output inductor. The total power dissipation of converter circuit can be measured by input power – output power. The thermal performance of the AOZ1024D is strongly affected by the PCB layout. Extra care should be taken by users during design process to ensure that the IC will operate under the recommended environmental conditions. The AOZ1024D is standard DFN5*4 package. Several layout tips are listed below for the best electric and thermal performance. Figure 3 on the next page illustrates a PCB layout example of AOZ1024D. 1. The LX pins are connected to internal PFET and NFET drains. They are low resistance thermal conduction path and most noisy switching node. Connected a large copper plane to LX pin to help thermal dissipation. For full load (4A) application, also connect the LX pads to the bottom layer by thermal vias to enhance the thermal dissipation. 2. Do not use thermal relief connection to the VIN and the PGND pin. Pour a maximized copper area to the PGND pin and the VIN pin to help thermal dissipation. 3. Input capacitor should be connected to the VIN pin and the PGND pin as close as possible. P total = V IN × I IN – V O × I O 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. The power dissipation of the inductor can be approximately calculated by output current and DCR of inductor. 5. Make the current trace from LX pins to L to CO to the PGND as short as possible. P inductor = IO2 × R inductor × 1.1 6. Pour copper plane on all unused board area and connect it to stable DC nodes, like VIN, GND or VOUT. The actual junction temperature can be calculated with power dissipation in the AOZ1024D and thermal impedance from junction to ambient. 7. Keep sensitive signal trace far away form the LX pins. T junction = ( P total – P inductor _loss ) × Θ JA Rev. 1.1 November 2007 www.aosmd.com Page 11 of 16 AOZ1024D Thermal Vias Bottom Layer Thermal Dissipation Figure 3. AOZ1024D (DFN 5x4) PCB Layout Figure 3. AOZ1024D (DFN 5x4) PCB Layout Rev. 1.1 November 2007 www.aosmd.com Page 12 of 16 AOZ1024D Package Dimensions, DFN 5x4 D A Pin #1 IDA D/2 B e 1 L E/2 R aaa C E E3 E2 Index Area (D/2 x E/2) D2 aaa C ccc C A3 D3 L1 Seating C Plane A ddd C A1 b bbb CAB Dimensions in millimeters Symbols A A1 A3 b D D2 D3 E E2 E3 e L L1 R aaa bbb ccc ddd Recommended Land Pattern 2.125 1.775 0.6 2.7 0.8 2.2 0.5 0.95 Unit: mm Min. 0.80 0.00 0.35 1.975 1.625 2.500 2.050 0.600 0.400 – – – – Nom. 0.90 0.02 0.20 REF 0.40 5.00 BSC 2.125 1.775 4.00 BSC 2.650 2.200 0.95 BSC 0.700 0.500 0.30 REF 0.15 0.10 0.10 0.08 Max. 1.00 0.05 0.45 2.225 1.875 2.750 2.300 0.800 0.600 – – – – Dimensions in inches Symbols A A1 A3 b D D2 D3 E E2 E3 e L L1 R aaa bbb ccc ddd Min. 0.031 0.000 Nom. Max. 0.035 0.039 0.001 0.002 0.008 REF 0.014 0.016 0.018 0.197 BSC 0.078 0.084 0.088 0.064 0.070 0.074 0.157 BSC 0.098 0.104 0.108 0.081 0.087 0.091 0.037 BSC 0.024 0.028 0.031 0.016 0.020 0.024 0.012 REF – 0.006 – – 0.004 – – 0.004 – – 0.003 – Notes: 1. Dimensions and tolerancing conform to ASME Y14.5M-1994. 2. All dimensions are in millimeters. 3. The location of the terminal #1 identifier and terminal numbering convention conforms to JEDEC publication 95 SP-002. 4. Dimension b applies to metallized terminal and is measured between 0.15mm and 0.30mm from the terminal tip. If the terminal has the optional radius on the other end of the terminal, the dimension b should not be measured in that radius area. 5. Coplanarity applies to the terminals and all other bottom surface metallization. 6. Drawing shown are for illustration only. Rev. 1.1 November 2007 www.aosmd.com Page 13 of 16 AOZ1024D Tape Dimensions, DFN 5x4 Tape R0 20 0. .40 T D1 E1 E2 D0 E B0 Feeding Direction K0 P0 A0 Unit: mm Package A0 B0 K0 D0 D1 E E1 E2 P0 P1 P2 T DFN 5x4 (12 mm) 5.30 ±0.10 4.30 ±0.10 1.20 ±0.10 1.50 Min. Typ. 1.50 +0.10 / –0 12.00 ±0.30 1.75 ±0.10 5.50 ±0.10 8.00 ±0.10 4.00 ±0.20 2.00 ±0.10 0.30 ±0.05 Leader/Trailer and Orientation Trailer Tape (300mm Min.) Rev. 1.1 November 2007 Components Tape Orientation in Pocket www.aosmd.com Leader Tape (500mm Min.) Page 14 of 16 AOZ1024D II R1 59 Reel Dimensions, DFN 5x4 I R1 6.0±1 21 M R1 I 27 Zoom In R6 R1 P 5 R5 B W1 III Zoom In 3-1.8 0.05 II ø1 /4 3-ø1 9± 0. " A ø2 . ø9 6± 0.2 05 A A N=ø100±2 3- 3- /8" Zoom In 1.8 6.0 1.8 6.45±0.05 8.00 6.2 ø2 2.20 1. 8.9±0.1 14 REF 0.00 0 5.0 ø13.0 R1.10 R3.10 C 1.8 12 REF 11.90 ø86 .0±0 10° 41.5 REF 43.00 44.5±0.1 44.5±0.1 .95 R3 4.0 6.10 VIEW: C 3- 8.0±0.1 ø3 " 16 ø3 / 3- 38° 40° 10.0 EF 8R 46.0±0.1 R0.5 .1 3.3 6.50 R4 R1 2.00 ø9 20 ø17.0 A 0.00 -0.05 /1 2.00 6.50 0.80 3.00 2.5 1.80 +0.05 6" 8.000.00 10.71 6° Rev. 1.1 November 2007 www.aosmd.com Page 15 of 16 AOZ1024D AOZ1024D Package Marking Z1024DI FAYWLT Part Number Code Assembly Lot Code Fab & Assembly Location Year & Week Code This data sheet 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. 1.1 November 2007 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 16 of 16