AOZ2263NQI-12

AOZ2263NQI-12 28V/12A Synchronous EZBuckTM Regulator General Description Features The AOZ2263NQI-12 is a high-efficiency, easy-to-use DC/DC synchronous buck regulator that operates up to 28V. The device is capable of supplying 12A of continuous output current with an output voltage adjustable down to 0.6V ±1%.  Wide input voltage range A proprietary constant on-time PWM control with input feed-forward results in ultra-fast transient response while maintaining relatively constant switching frequency over the entire input voltage range. The on time can be externally programmed up to 2.6µs. – 2V to 28V  12A continuous output current  Output voltage adjustable down to 0.6V (±1.0%)  Low RDS(ON) internal NFETs – 11m high-side – 8m low-side  Constant On-Time with input feed-forward  Programmable on-time up to 2.6µs The device features multiple protection functions such as VCC under-voltage lockout, cycle-by-cycle current limit, output over-voltage protection, short-circuit protection, and thermal shutdown.  Selectable PFM light-load operation The AOZ2263NQI-12 is available in a 4mm×4mm QFN23L package and is rated over a -40°C to +85°C ambient temperature range.  Discharge Function  Ceramic capacitor stable  Adjustable soft start  Ripple reduction  Power Good output  Integrated bootstrap diode  Adjustable cycle-by-cycle current limit  Short-circuit protection  Over-voltage protection  Thermal shutdown  Thermally enhanced 4mm x 4mm QFN-23L package Applications  Portable computers  Compact desktop PCs  Servers  Graphics cards  Set-top boxes  LCD TVs  Cable modems  Point-of-load DC/DC converters  Telecom/Networking/Datacom equipment Rev. 1.1 August 2022 www.aosmd.com Page 1 of 17 AOZ2263NQI-12 Typical Application RTON INPUT 2V to 28V IN TON C2 22µF OCS ROCS VCC 5V R3 100k C4 4.7µF POWER GOOD AOZ2263NQI-12 C5 0.1µF BST PGOOD LX OFF ON EN/DISCHG L1 1µH OUTPUT 1.05V, 12A R2 FB MODE C3 132µF R1 SS AGND CSS PGND POWER GROUND ANALOG GROUND Rev. 1.1 August 2022 www.aosmd.com Page 2 of 17 AOZ2263NQI-12 Ordering Information Part Number Ambient Temperature Range Package Environmental AOZ2263NQI-12 -40°C to +85°C 23-Pin 4mm x 4mm QFN Green Product AOS Green Products use reduced levels of Halogens, and are also RoHS compliant. Please visit www.aosmd.com/media/AOSGreenPolicy.pdf for additional information. Pin Configuration SS IN VCC BST OCS LX 23 22 21 20 19 18 PGOOD 1 17 LX EN/DISCHG 2 16 LX MODE 3 15 PGND 14 PGND LX IN 11 PGND LX 12 10 6 LX TON 9 PGND IN 13 8 5 IN FB 7 4 IN AGND 23-Pin 4mm x 4mm QFN Top View Rev. 1.1 August 2022 www.aosmd.com Page 3 of 17 AOZ2263NQI-12 Pin Description Pin Number Pin Name Pin Function PGOOD Power Good Signal Output. PGOOD is an open-drain output used to indicate the status of the output voltage. It is internally pulled low when the output voltage is 15% lower than the nominal regulation voltage or 50% higher than the nominal regulation voltage. PGOOD is pulled low during soft-start and shut down. 2 EN/DISCHG Enable Input. The AOZ2263NQI-12 is enabled when EN is pulled high. The device shuts down when EN is pulled low. Assert EN to high for power-up after IN and VCC are well supplied. Power-off the device by EN off is suggested. Set voltage level higher/lower than discharge threshold when PGOOD pull high to enable/disable output discharge function. 3 MODE PFM Selection Input. Connect MODE pin to VCC for forced PWM operation. Connect MODE pin to ground for PFM operation to improve light load efficiency. 4 AGND Analog Ground. 5 FB 6 TON 7, 8, 9, 22 IN 12, 13, 14, 15 PGND Power Ground. 10, 11, 16, 17, 18 LX Switching Node. 19 OCS Current limitation level setting pin. Connect a resistor between OCS and GND to set over current protection level. No capacitor is allowed between OCS and AGND. 20 BST Bootstrap Capacitor Connection. The AOZ2263NQI-12 includes an internal bootstrap diode. Connect an external capacitor between BST and LX as shown in the Typical Application diagram. 21 VCC Supply Input for analog functions. Bypass VCC to AGND with a 4.7µF~10µF ceramic capacitor. Place the capacitor close to VCC pin. 23 SS 1 Rev. 1.1 August 2022 Feedback Input. Adjust the output voltage with a resistive voltage-divider between the regulator’s output and AGND. On-Time Setting Input. Connect a resistor between VIN and TON to set the on time. Supply Input. IN is the regulator input. All IN pins must be connected together. Soft-Start Time Setting Pin. Connect a capacitor between SS and AGND to set the soft-start time. www.aosmd.com Page 4 of 17 AOZ2263NQI-12 Absolute Maximum Ratings Maximum Operating Ratings Exceeding the Absolute Maximum Ratings may damage the device. The device is not guaranteed to operate beyond the Maximum Operating Ratings. Parameter Rating IN, TON to AGND Parameter -0.3V to 30V Supply Voltage (VIN) LX to AGND -1.0V to 30V Output Voltage Range BST to AGND -0.3V to 36V Ambient Temperature (TA) (1) SS, OCS, PGOOD, FB to AGND -0.3V to 6V EN/DISCH, VCC, MODE to AGND -0.3V to 6V PGND to AGND Rating 2V to 28V 0.6V to 0.85*VIN -40°C to +85°C Package Thermal Resistance (θJA) 32°C/W -0.3V to +0.3V Junction Temperature (TJ) +150°C Storage Temperature (TS) -65°C to +150°C ESD Rating(2) 2kV Notes: 1. LX to PGND Transient (t 2V, PFM mode IOFF Shutdown Supply Current VEN = 0V VFB Feedback Voltage TA = 25°C IFB Min. Typ. 2 3.2 4.2 3.9 Max Units 28 V 4.5 V V 350 0.594 µA 1 20 µA 0.600 0.606 V Load Regulation 0.5 % Line Regulation 1 % FB Input Bias Current 200 nA 0.5 V V Enable/Discharge VEN EN Input Threshold VEN_HYS EN Input Hysteresis VDIS Discharge Threshold Off threshold On threshold 1.2 100 When PGOOD from 0 to 1 250 mV 1.5 V MODE Control VMODE MODE Input Threshold VMODEHYS MODE Input Hysteresis PFM Mode threshold Force PWM threshold 0.5 1.2 100 V V mV Modulator TON On Time 200 ns TON_MIN Minimum On Time 100 ns TON_MAX Maximum On Time 2.6 µs TOFF_MIN Minimum Off Time 300 ns Rev. 1.1 August 2022 RTON = 100k, VIN = 12V www.aosmd.com Page 5 of 17 AOZ2263NQI-12 Electrical Characteristics TA = 25°C, VIN = 12V, VCC = 5V, EN = 5V, unless otherwise specified. Specifications in BOLD indicate a temperature range of -40°C to +85°C. Symbol Parameter Conditions Min. Typ. Max Units 7 11 15 µA 0.5 V ±1 µA Soft-Start ISS_OUT SS Source Current VSS = 0V CSS = 0.001µF to 0.1µF Power Good Signal VPG_LOW PGOOD Low Voltage IOL = 1mA PGOOD Leakage Current VPGH PGOOD Threshold (Low Level to High Level) FB rising 90 % VPGL PGOOD Threshold (High Level to Low Level) FB rising FB falling 150 85 % % 5 % PGOOD Threshold Hysteresis Under Voltage and Over Voltage Protection VPL Under Voltage Threshold TPL Under Voltage Delay Time VPH Over Voltage Threshold FB falling FB rising 50 % 32 µs 150 % Power Stage Output RDS(ON) RDS(ON) High-Side NFET On-Resistance VIN = 12V, VCC = 5V High-Side NFET Leakage VEN = 0V, VLX = 0V Low-Side NFET On-Resistance VLX = 12V, VCC = 5V Low-Side NFET Leakage VEN = 0V 11 m 10 8 µA m 10 µA Thermal Protection Thermal Shutdown Threshold Rev. 1.1 August 2022 TJ rising TJ falling www.aosmd.com 150 100 °C °C Page 6 of 17 AOZ2263NQI-12 Functional Block Diagram BST IN PGood VCC DISCHARGE UVLO EN/DIS Reference & Bias TOFF_MIN Q Timer Error Comp 0.6V SS ISENSE (AC) FB PG Logic S Q R FB Decode LX ILIM Comp Current Information Processing + OCS ISENSE ISENSE (AC) LX Vcc TON OTP Q Timer MODE TON TON Generator Light Load Threshold Light Load Comp Discharge Pulse ISENSE DIS_On EN PGND Rev. 1.1 August 2022 www.aosmd.com AGND Page 7 of 17 AOZ2263NQI-12 Typical Performance Characteristics TA = 25°C, VIN = 19V, VOUT = 1V, fS = 450kHz, unless otherwise specified. Normal Operation Load Transient 0A to 12A ILX (5A/div) ILX (5A/div) VO ripple (50mV/div) VO ripple (50mV/div) VLX (20V/div) 10µs/div 2ms/div Full Load Start-up Short Circuit Protection VLX (20V/div) VLX (20V/div) EN (5V/div) ILX (10A/div) ILX (5A/div) VO (500mV/div) VO (500mV/div) 2ms/div 50µs/div Efficiency vs. Load Current 100 90 80 VOUT = 1V Efficiency (%) 70 60 50 40 Vin = 6.5V 30 Vin = 12V 20 Vin = 19V 10 Vin = 24V 0 0 Rev. 1.1 August 2022 2.0 8.0 6.0 Output Current (A) 4.0 www.aosmd.com 10.0 12.0 Page 8 of 17 AOZ2263NQI-12 Detailed Description The AOZ2263NQI-12 is a high-efficiency, easy-to-use, synchronous buck regulator optimized for notebook computers. The regulator is capable of supplying 12A of continuous output current with an output voltage adjustable down to 0.6V. The programmable on-time from 100ns to 2.6µs enables optimizing the configuration for PCB area and efficiency. The input voltage of AOZ2263NQI-12 can be as low as 2.7JuneV. The highest input voltage of AOZ2263NQI-12 can be 28V. Constant on-time PWM with input feedforward control scheme results in ultra-fast transient response while maintaining relatively constant switching frequency over the entire input range. True AC current mode control scheme guarantees the regulator can be stable with ceramics output capacitor. The switching frequency can be externally programmed. Protection features include VCC under-voltage lockout, current limit, output over voltage and under voltage protection, shortcircuit protection, and thermal shutdown. The AOZ2263NQI-12 is available in 23-pin 4mm×4mm QFN package. Enable and Soft Start The AOZ2263NQI-12 has external soft start feature to limit in-rush current and ensure the output voltage ramps up smoothly to regulate voltage. A soft start process begins when VCC rises to 4.5V and voltage on EN pin is HIGH. An internal current source charges the external soft-start capacitor; the FB voltage follows the voltage of soft-start pin (VSS) when it is lower than 0.6V. When VSS is higher than 0.6V, the FB voltage is regulated by internal precise band-gap voltage (0.6V). When VSS is higher than 1.2V, the PGOOD signal is high. The softstart time for PGOOD can be calculated by the following formula: TSS(µs) = 120 x CSS(nF) Rev. 1.1 August 2022 If CSS is 1nF, the soft-start time will be 120µs; if CSS is 3.6nF, the soft-start time will be 432µs. VOUT VCC Level VSS 1.2V 0.6VREF VEN PGOOD TSS Figure 1. Soft-Start Sequence of AOZ2263NQI-12 Enable and Discharge Function AOZ2263NQI-12 pin 2 is a multi-function pin, which combines enable and discharge function together. Discharge function on/off is determined by the voltage level on this pin at PGOOD rising edge. Figure 2 illustrates how to activate discharge function. Once PGOOD signal rises up, AOZ2263NQI-12 detects the voltage on EN/DIS pin. Discharge function will be activated (Dis_on set to 1) only if EN/DIS pin voltage is under discharge threshold at that moment. Dis_on keeps high until next PGOOD rising edge and will be overwritten. Discharge function won’t be activated (Dis_on set to 0) if EN/DIS pin voltage is over discharge threshold at PGOOD rising edge. Dis_on keeps low until next PGOOD rising edge and will be overwritten. AOZ2263NQI-12 enters discharge mode if Dis_on signal is high when EN/DIS pin voltage is lower than EN off threshold. Discharge MOSFET is always turn-on during discharge mode. At the mean while, low-side MOSFET turns on and off to quickly discharge output voltage. All protection and COT are disabled during discharge mode. Discharge mode operation ended when FB voltage is under 40mV. www.aosmd.com Page 9 of 17 AOZ2263NQI-12 Discharge threshold = 1.5V EN/DIS EN on threshold = 1.2V EN off threshold = 0.5V PGOOD Dis_on Discharge mode activated No PGOOD One shot, Discharge Mode keep activated No PGOOD One shot, Discharge Mode keep disabled Discharge mode not activated Figure 2. AOZ2263NQI-12 Discharge Function On/Off Setting Constant-On-Time PWM Control with Input Feed Forward The internal circuit of AOZ2261NQI-12 sets the on-time of high-side switch inversely proportional to the IN. The control algorithm of AOZ2263NQI-12 is constant-ontime PWM Control with input feed-forward. TON v The simplified control schematic is shown in Figure. 3. The high-side switch on-time is determined solely by a one-shot whose pulse width can be programmed by one external resistor and is inversely proportional to input voltage (IN). The one-shot is triggered when the internal 0.6V is higher than the combined information of FB voltage and the AC current information of inductor, which is processed and obtained through the sensed lower-side MOSFET current once it turns-on. The added AC current information can help the stability of constant-on time control even with pure ceramic output capacitors, which have very low ESR. The AC current information has no DC offset, which does not cause offset with output load change, which is fundamentally different from other V2 constant-on time control schemes. IN FB Voltage/ AC Current Information PWM Programmable One-Shot – FSW VOUT VIN × T ON (2) Once the product of VIN x TON is constant, the switching frequency keeps constant and is independent with input voltage. An external resistor between the IN and TON pin sets the switching on-time according to the following equation: ((ns) ns) TTON ON R ( kΩ ) RTON TON ( kΩ ) × 25 × 25 V (V) VIN IN (V) (3) (3) Then, the switching frequency can be estimated by: FSW ( kHz) = VOUT VOUT 6 4 × 10 = × 4 × 10 (4) VIN* T ON( ns ) RTON (kΩ) 0.6V Figure 3. Simplified Control Schematic of AOZ2263NQI-12 The constant-on-time PWM control architecture is a pseudo-fixed frequency with input voltage feed-forward. Rev. 1.1 August 2022 (1) To achieve the flux balance of inductor, the buck converter has the equation: Comp + RTON( kΩ ) VIN (V) If VOUT is 1.05V, VIN is 19V, and set FS = 500kHz. According to equation 3, TON = 110ns is needed. Finally, use the TON to RTON curve, we can find out RTON is 84k. www.aosmd.com Page 10 of 17 AOZ2263NQI-12 This algorithm results in a nearly constant switching frequency despite the lack of a fixed-frequency clock generator. describes the action when over current condition happens. True Current Mode Control The constant-on-time control scheme is intrinsically unstable if output capacitor’s ESR is not large enough as an effective current-sense resistor. Ceramic capacitors usually can not be used as output capacitor. The AOZ2263NQI-12 senses the low-side MOSFET current and processes it into DC current and AC current information using AOS proprietary technique. The AC current information is decoded and added on the FB pin on phase. With AC current information, the stability of constant-on-time control is significantly improved even without the help of output capacitor’s ESR; and thus the pure ceramic capacitor solution can be applied. The pure ceramic capacitor solution can significantly reduce the output ripple (no ESR caused overshoot and undershoot) and less board area design. Current-Limit Protection The AOZ2263NQI-12 has the current-limit protection by using RDS(ON) of the low-side MOSFET to be as current sensing. To detect real current information, a minimum constant off (300ns typical) is implemented after a constant on time. If the current exceeds the current-limit threshold, the PWM controller is not allowed to initiate a new cycle. The actual peak current is greater than the current-limit threshold by an amount equal to the inductor ripple current. Therefore, the exact current-limit characteristic and maximum load capability are a function of the inductor value and input and output voltages. The current limit will keep the low-side MOSFET on and will not allow another high-side on-time, until the current in the low-side MOSFET reduces below the current limit. Current-Limit Setting The current-limit threshold mentioned in last paragraph can be set by connecting a resistor between OCS pin and ground. The value of the current limit resistor (ROCS) can be calculated according to the equation below. And the value of ROCS is need higher than 18k. A capacitor from OCS pin to ground would impact the current limit accuracy and is not allowed. IL_LIMIT(A) 1.11*ROCS(kΩ) - 2.22 (5) As shown in Figure 4, once the magnitude of switch node voltage VLX is larger than VOCS, over current signal is triggered. The larger ROCS is, the higher over current threshold will be. Section Current-Limit Protection Rev. 1.1 August 2022 IREF OCS OCL signal ROCS LX = -IL x RDS(ON) GND OCL level 
ROCS Figure 4. Illustration of Current Limit Setting Output Voltage Under-Voltage Protection If the output voltage is lower than 50% by over-current or short circuit, AOZ2263NQI-12 will wait for 32µs (typical) and turns-off both high-side and low-side MOSFETs and latches off. Only when triggered, the enable can restart the AOZ2263NQI-12 again. Output Voltage Over-Voltage Protection The threshold of OVP is set 50% higher than 0.6V. When the VFB voltage exceeds the OVP threshold, high-side MOSFET is turn-off and low-side MOSFETs is turn-on 1µs, then latch-off. Power Good Output The power good (PGOOD) output, which is an open drain output, requires the pull-up resistor. When the output voltage is 15% below the nominal regulation voltage, the PGOOD is pulled low. When the output voltage is 50% higher than the nominal regulation voltage, the PGOOD is also pull low. When combined with the under-voltage-protection circuit, this current limit method is effective in almost every circumstance. Ripple Reduction When switching frequency is down to half of setting during PFM, AOZ2263NQI-12 actively reduces on-time pulse width to reduce inductor current ripple and output voltage ripple. Ripple reduction not only reduces half of voltage ripple but also decreases the chance of acoustic noise under light load. www.aosmd.com Page 11 of 17 AOZ2263NQI-12 Application Information The basic AOZ2263NQI-12 application circuit is shown in page 2. Component selection is explained below. Input Capacitor The input capacitor must be connected to the IN pins and PGND pin of the AOZ2263NQI-12 to maintain steady input voltage and filter out the pulsing input current. A small decoupling capacitor, usually 4.7µF, should be connected to the VCC pin and AGND pin for stable operation of the AOZ2263NQI-12. The voltage rating of input capacitor must be greater than maximum input voltage plus ripple voltage. Inductor The input ripple voltage can be approximated by equation below: IOUT VIN = ----------------f CIN VOUT 1 – --------VIN VOUT --------VIN (6) 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: VOUT VOUT --------- 1 – --------VIN VIN ICIN_RMS = IOUT 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 ripple current rating. Depending on the application circuits, other low ESR tantalum capacitor or aluminum electrolytic capacitor may also be used. When selecting ceramic capacitors, X5R or X7R type dielectric ceramic capacitors are preferred for their better temperature and voltage characteristics. Note that the ripple current rating from capacitor manufactures is based on certain amount of life time. Further de-rating may be necessary for practical design requirement. (7) if let m equal the conversion ratio: VOUT --------- = m VIN (8) The relation between the input capacitor RMS current and voltage conversion ratio is calculated and shown in Figure 5. 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. 0.5 0.4 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: OUT ∆ IL = V -------f L VOUT 1 – --------VIN (9) The peak inductor current is: I I Lpeak = IOUT + -------L2 (10) High inductance gives low inductor ripple current but requires 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 30% to 50% 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. The inductor takes the highest current in a buck circuit. The conduction loss on inductor needs to be checked for thermal and efficiency requirements. 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 5. ICIN vs. Voltage Conversion Ratio Rev. 1.1 August 2022 www.aosmd.com Page 12 of 17 AOZ2263NQI-12 Output Capacitor 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; VOUT = 1 ESR C + ------------------------O 8 f CO IL (11) where CO is output capacitor value and ESRCO is the Equivalent Series Resistor of output capacitor. When a low ESR ceramic capacitor is used as 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: VOUT = IL 1 ------------------------8 f CO (12) 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: VOUT = IL ESR C (13) O In the AOZ2263NQI-12 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 low side switch. Current flows in the second loop when the low side switch 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 AOZ2263NQI-12. In the AOZ2263NQI-12 buck regulator circuit, the major power dissipating components are the AOZ2263NQI-12 and the output inductor. The total power dissipation of converter circuit can be measured by input power minus output power. 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: (14) VIN u IIN – VOUT u IOUT Ptotal_loss (15) The power dissipation of inductor can be approximately calculated by DCR of inductor and output current. Pinductor_loss IOUT2 u Rinductor u 1.1 (16) The actual junction temperature can be calculated with power dissipation in the AOZ2263NQI-12 and thermal impedance from junction to ambient. Tjunction For lower output ripple voltage across the entire operating temperature range, X5R or X7R dielectric type of ceramic, or other low ESR tantalum are recommended to be used as output capacitors. IL I CO_RMS = ---------12 Thermal Management and Layout Consideration (Ptotal_loss  Ptotal_loss) u θJA + TA (17) The maximum junction temperature of AOZ2263NQI-12 is 150ºC, which limits the maximum load current capability. The thermal performance of the AOZ2263NQI-12 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. 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. Rev. 1.1 August 2022 www.aosmd.com Page 13 of 17 AOZ2263NQI-12 Layout Considerations Several layout tips are listed below for the best electric and thermal performance. 1. The LX pins and pad are connected to internal low side switch drain. They are low resistance thermal conduction path and most noisy switching node. Connect a large copper plane to LX pin to help thermal dissipation. 5. Voltage divider R1 and R2 should be placed as close as possible to FB and AGND. 6. RTON should be connected as close as possible to Pin 6 (TON pin). 7. A ground plane is preferred. 2. The IN pins and pad are connected to internal high side switch drain. They are also low resistance thermal conduction path. Connect a large copper plane to IN pins to help thermal dissipation. 8. Keep sensitive signal traces such as feedback trace far away from the LX pins. 9. Pour copper plane on all unused board area and connect it to stable DC nodes, like VIN, GND or VOUT. 3. Input capacitors should be connected to the IN pin and the PGND pin as close as possible to reduce the switching spikes. 10. The current limit resistor (ROCS) should be connected as close as possible to Pin 19 (OCS). Place three GND vias to connect to inner ground layer. Keep distance between Rocs and Lx plane. 4. Decoupling capacitor CVCC should be connected to VCC and AGND as close as possible. AGND EN PGOOD 2 1 11 3 LX LX 10 IN LX 4 9 AGND IN 5 8 FB IN 6 GND 23 SS 22 IN 21 VCC 20 BST 19 OCS 18 LX GND 17 LX 16 LX 15 PGND 14 PGND 13 PGND 12 PGND PGND 7 TON VIN IN MODE VOUT VOUT Rev. 1.1 August 2022 www.aosmd.com Page 14 of 17 AOZ2263NQI-12 Package Dimensions, QFN4x4B-23L Rev. 1.1 August 2022 www.aosmd.com Page 15 of 17 AOZ2263NQI-12 Tape and Reel Dimensions, QFN4x4B-23L Rev. 1.1 August 2022 www.aosmd.com Page 16 of 17 AOZ2263NQI-12 Part Marking AOZ2263NQI-12 (QFN 4x4) BKNC Part Number Code YWLT Year & Week Code Assembly Lot Code LEGAL DISCLAIMER Applications or uses as critical components in life support devices or systems are not authorized. Alpha and Omega Semiconductor does not assume any liability arising out of such applications or uses of its products. AOS reserves the right to make changes to product specifications without notice. It is the responsibility of the customer to evaluate suitability of the product for their intended application. Customer shall comply with applicable legal requirements, including all applicable export control rules, regulations and limitations. AOS's products are provided subject to AOS’s terms and conditions of sale which are set forth at: http://www.aosmd.com/terms_and_conditions_of_sale LIFE SUPPORT POLICY ALPHA AND 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 August 2022 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 17 of 17