AP63200/AP63201/AP63203/AP63205 3.8V TO 32V INPUT, 2A LOW IQ SYNCHRONOUS BUCK WITH ENHANCED EMI REDUCTION Description Pin Assignments The AP63200/AP63201/AP63203/AP63205 is a 2A, synchronous buck converter with a wide input voltage range of 3.8V to 32V and fully integrates a 125m high-side power MOSFET and a 68m lowside power MOSFET to provide high-efficiency step-down DC/DC conversion. TOP VIEW The AP63200/AP63201/AP63203/AP63205 device is easily used by minimizing the external component count due to its adoption of peak current mode control along with its integrated compensation network. The AP63200/AP63201/AP63203/AP63205 has optimized designs for Electromagnetic Interference (EMI) reduction. The converter features Frequency Spread Spectrum (FSS) with a switching frequency jitter of 6%, which reduces EMI by not allowing emitted energy to stay in any one frequency for a significant period of time. It also has a proprietary gate driver scheme to resist switching node ringing without sacrificing MOSFET turn-on and turn-off times, which further erases highfrequency radiated EMI noise caused by MOSFET switching. FB 1 6 BST EN 2 5 SW VIN 3 4 GND TSOT26 The device is available in a low-profile, TSOT26 package. Features Applications * VIN 3.8V to 32V * * * * 2A Continuous Output Current 0.8V 1% Reference Voltage 22A Ultralow Quiescent Current Switching Frequency o 500kHz: AP63200 and AP63201 o 1.1MHz: AP63203 and AP63205 Pulse Width Modulation (PWM) Regardless of Output Load o AP63201 Supports Pulse Frequency Modulation (PFM) o AP63200, AP63203, and AP63205 o Up to 80% Efficiency at 1mA Light Load o Up to 88% Efficiency at 5mA Light Load Fixed Output Voltage o 3.3V: AP63203 o 5.0V: AP63205 Proprietary Gate Driver Design for Best EMI Reduction Frequency Spread Spectrum (FSS) to Reduce EMI Precision Enable Threshold to Adjust UVLO Protection Circuitry o Overvoltage Protection o Cycle-by-Cycle Peak Current Limit o Thermal Shutdown Totally Lead-Free & Fully RoHS Compliant (Notes 1 & 2) Halogen and Antimony Free. "Green" Device (Note 3) * * * * * * * * * * * * * * * * * * * Notes: 12V and 24V Distributed Power Bus Supplies Flat Screen TV Sets and Monitors Power Tools and Laser Printers White Goods and Small Home Appliances FPGA, DSP, and ASIC Supplies Home Audio Network Systems Set Top Boxes Gaming Consoles Consumer Electronics 1. No purposely added lead. Fully EU Directive 2002/95/EC (RoHS), 2011/65/EU (RoHS 2) & 2015/863/EU (RoHS 3) compliant. 2. See https://www.diodes.com/quality/lead-free/ for more information about Diodes Incorporated's definitions of Halogen- and Antimony-free, "Green" and Lead-free. 3. Halogen- and Antimony-free "Green" products are defined as those which contain <900ppm bromine, <900ppm chlorine (<1500ppm total Br + Cl) and <1000ppm antimony compounds. AP63200/AP63201/AP63203/AP63205 Document number: DS41326 Rev. 2 - 2 1 of 18 www.diodes.com January 2019 (c) Diodes Incorporated AP63200/AP63201/AP63203/AP63205 Typical Application Circuit INPUT 3 VIN 6 BST C3 100nF L 4.7H 2 EN AP63205 VOU T 5V 1 FB C1 10F OUTPUT 5 SW C2 2x22F 4 GND Figure 1. Typical Application Circuit Figure 2. Efficiency vs. Output Current Pin Descriptions Pin Number Pin Name 1 FB 2 EN 3 VIN 4 GND 5 SW 6 BST Function Feedback sensing terminal for the output voltage. Connect this pin to the resistive divider of the output. See Setting the Output Voltage section for more details. Enable Input. EN is a digital input that turns the regulator on or off. Drive EN high to turn on the regulator and low to turn it off. Attach to VIN or leave open for automatic startup. The EN has a precision threshold of 1.18V for programing the UVLO. See Enable section for more details. Power Input. VIN supplies the power to the IC, as well as the step-down converter switches. Drive VIN with a 3.8V to 32V power source. Bypass VIN to GND with a suitably large capacitor to eliminate noise due to the switching of the IC. See Input Capacitor section for more details. Power Ground. Power Switching Output. SW is the switching node that supplies power to the output. Connect the output LC filter from SW to the output load. Note that a capacitor is required from SW to BST to power the high-side switch. High-Side Gate Drive Boost Input. BST supplies the drive for the high-side N-Channel MOSFET. A 100nF capacitor is recommended from SW to BST to power the high-side switch. AP63200/AP63201/AP63203/AP63205 Document number: DS41326 Rev. 2 - 2 2 of 18 www.diodes.com January 2019 (c) Diodes Incorporated AP63200/AP63201/AP63203/AP63205 Functional Block Diagram EN 2 1.18V 20k + ON - 0.4V 0.8V 1.1V Internal Reference VCC Regulator 3 VIN 1.5A 4A 1 + 0.6V - UVP Oscillator SE = 0.84V/T + - FB CSA + RT = 0.2V/A 6 BST Ref OCP - 0.8V Internal SS + gm + Error Amplifier VSUM COMP + - 18k Logic Q1 PWM Comparator 7.6nF 5 SW Q2 4 GND Figure 3. Functional Block Diagram AP63200/AP63201/AP63203/AP63205 Document number: DS41326 Rev. 2 - 2 3 of 18 www.diodes.com January 2019 (c) Diodes Incorporated AP63200/AP63201/AP63203/AP63205 Absolute Maximum Ratings (Note 4) (@TA = +25C, unless otherwise specified.) Symbol Parameter Rating Unit VIN Supply Voltage -0.3 to +35.0 (DC) -0.3 to +40.0 (400ms) V V VSW Switch Node Voltage -1.0 to VIN + 0.3 V VBST Bootstrap Voltage VSW - 0.3 to VSW + 6.0 V V VFB Feedback Voltage -0.3V to +6.0 VEN Enable/UVLO Voltage -0.3V to +35.0 V TST Storage Temperature -65 to +150 C TJ Junction Temperature +160 C Lead Temperature +260 C Human Body Mode Charge Device Model 2000 1000 V V TL ESD Susceptibility (Note 5) HBM CDM Notes: 4. Stresses greater than the 'Absolute Maximum Ratings' specified above may cause permanent damage to the device. These are stress ratings only; functional operation of the device at these or any other conditions exceeding those indicated in this specification is not implied. Device reliability may be affected by exposure to absolute maximum rating conditions for extended periods of time. 5. Semiconductor devices are ESD sensitive and may be damaged by exposure to ESD events. Suitable ESD precautions should be taken when handling and transporting these devices. Thermal Resistance (Note 6) Note: Symbol Parameter JA Junction to Ambient TSOT26 Rating 89 C/W Unit JC Junction to Case TSOT26 39 C/W 6. Test condition for TSOT26: Device mounted on FR-4 substrate, single-layer PC board, 2oz copper, with minimum recommended pad layout. Recommended Operating Conditions (Note 7) (@TA = +25C, unless otherwise specified.) Note: Symbol Parameter Min Max VIN Supply Voltage 3.8 32 Unit V TA Operating Ambient Temperature Range -40 +85 C 7. The device function is not guaranteed outside of the recommended operating conditions. AP63200/AP63201/AP63203/AP63205 Document number: DS41326 Rev. 2 - 2 4 of 18 www.diodes.com January 2019 (c) Diodes Incorporated AP63200/AP63201/AP63203/AP63205 Electrical Characteristics (TA = +25C, VIN = 12V, unless otherwise specified. Min/Max limits apply across the recommended ambient temperature range, -40C to +85C, and input voltage range, 3.8V to 32V). Symbol ISHDN IQ UVLO Parameter Test Conditions Shutdown Supply Current VEN = 0V Supply Current (Quiescent) AP63201: VEN = OPEN, VFB = 1.0V AP63200/AP63203/AP63205: VEN = OPEN, VFB = 1.0V Min Typ Max Unit -- 1 3 A -- 258 -- A -- 22 -- A VIN Under Voltage Threshold (Rising) -- 3.30 3.50 3.70 V VIN Under Voltage Threshold Hysteresis -- -- 440 -- mV RDS(ON)1 High-Side Switch On-Resistance (Note 8) -- -- 125 -- m RDS(ON)2 Low-Side Switch On-Resistance (Note 8) -- -- 68 -- m IPEAK_LIMIT HS Peak Current Limit (Note 8) -- 2.5 2.8 3.1 A IVALLEY_LIMIT LS Valley Current Limit (Note 8) -- 2.5 3.2 3.9 A AP63200/AP63201 AP63203/AP63205 -- -- -- -- 500 1100 6 -- -- -- kHz kHz % fSW Oscillator Frequency FSS Frequency Spread Spectrum tON Minimum On Time -- Feedback Voltage CCM, AP63200/AP63201 CCM, AP63203 CCM, AP63205 VFB Note: -- 80 -- ns 792 3.27 4.95 800 3.30 5.00 808 3.33 5.05 mV V V VEN_H EN Logic High -- 1.15 1.18 1.23 V VEN_L EN Logic Low -- 1.05 1.10 1.15 V VEN = 1.5V -- 5.5 -- A IEN EN Input Current VEN = 1V -- 1.5 -- A tSS Soft-Start Period -- -- 4 -- ms TSD Thermal Shutdown (Note 8) -- -- +160 -- C THYS Thermal Hysteresis (Note 8) -- -- +25 -- C 8. Compliance to the datasheet limits is assured by one or more methods: production test, characterization, and/or design. AP63200/AP63201/AP63203/AP63205 Document number: DS41326 Rev. 2 - 2 5 of 18 www.diodes.com January 2019 (c) Diodes Incorporated AP63200/AP63201/AP63203/AP63205 Typical Performance Characteristics (AP63200 @TA = +25C, VIN = 12V, VOUT = 5V, unless otherwise specified.) Figure 4. Efficiency vs. Output Current, VIN = 12V Figure 5. Efficiency vs. Output Current, VIN = 24V Figure 6. Load Regulation, VOUT = 5V Figure 7. Line Regulation, VOUT = 5V Figure 8. Feedback Voltage vs. Temperature Figure 9. Power Switch RDS(ON) vs. Temperature AP63200/AP63201/AP63203/AP63205 Document number: DS41326 Rev. 2 - 2 6 of 18 www.diodes.com January 2019 (c) Diodes Incorporated AP63200/AP63201/AP63203/AP63205 Typical Performance Characteristics (continued) Figure 10. IQ vs. Temperature Figure 11. ISHDN vs. Temperature Figure 12. FSW vs. Temperature Figure 13. VIN POR and UVLO vs. Temperature EN (5V/div) EN (5V/div) VOUT (2V/div) IL (2A/div) VOUT (2V/div) IL (2A/div) SW (10V/div) SW (10V/div) 2ms/div 50s/div Figure 14. Startup using EN, Iout = 2A Figure 15. Shutdown using EN, Iout = 2A AP63200/AP63201/AP63203/AP63205 Document number: DS41326 Rev. 2 - 2 7 of 18 www.diodes.com January 2019 (c) Diodes Incorporated AP63200/AP63201/AP63203/AP63205 Typical Performance Characteristics (continued) VOUT Ripple (20mV/div) VOUT Ripple (500mV/div) IL (1A/div) SW (10V/div) IOUT (1A/div) 2s/div 1ms/div Figure 16. Output Ripple, Iout = 2A Figure 17. Load Transient, Iout = 1A to 2A VOUT (2V/div) VOUT (2V/div) IL (2A/div) SW (10V/div) IL (2A/div) 10ms/div SW (10V/div) Figure 18. Output Short Protection, Iout = 2A AP63200/AP63201/AP63203/AP63205 Document number: DS41326 Rev. 2 - 2 10ms/div Figure 19. Output Short Recovery, Iout = 2A 8 of 18 www.diodes.com January 2019 (c) Diodes Incorporated AP63200/AP63201/AP63203/AP63205 Application Information INPUT 3 VIN 2 EN 6 BST AP63200 AP63201 5 SW C3 100nF L 2.2H VOUT 1.2V C4 100pF 1 FB C1 10F OUTPUT R1 30.9k C2 2x22F R2 62k 4 GND Figure 20. Typical Application Circuit of AP63200/AP63201 INPUT 3 VIN 6 BST 2 EN 5 AP63203 SW AP63205 C3 100nF OUTPUT L VOUT 1 FB C1 10F C2 2x22F 4 GND Figure 21. Typical Application Circuit of AP63203/AP63205 1 PWM Operation Control The AP63200/AP63201/AP63203/AP63205 device is a 3.8V-to-32V input, 2A output, EMI friendly, fully integrated synchronous buck converter. Refer to the block diagram in Figure 3. The device employs fixed-frequency peak current mode control. The internal clock's rising edge (500kHz for AP6300 and AP63201, 1.1MHz for AP63203 and AP63205) initiates turning on the integrated high-side power MOSFET, Q1, for each cycle. When Q1 is on, the inductor current rises linearly, and the device charges the output capacitor. The current across Q1 is sensed and converted to a voltage with a ratio of RT via the CSA block. The CSA output is combined with an internal slope compensation, SE, resulting in VSUM. When VSUM rises higher than the internal COMP node, the device turns off Q1 and turns on the low-side power MOSFET, Q2. The inductor current decreases when Q2 is on. On the rising edge of next clock cycle, Q2 turns off, and Q1 turns on. This sequence repeats every clock cycle. The peak current mode control with the internal loop compensation network and AP63200/AP63201/AP63203/AP63205 footprint as well as minimizes the external component count. built-in 4ms soft-start simplifies the The error amplifier generates the COMP voltage by comparing the voltage on the FB pin with an internal 0.8V reference. An increase in load current causes the feedback voltage to drop. The error amplifier thus raises the COMP voltage until the average inductor current matches the increased load current. This feedback loop regulates the output voltage. The device also integrates internal slope compensation circuitry to prevent subharmonic oscillation when the duty cycle is greater than 50% for peak current mode control. The AP63200/AP63201/AP63203/AP63205 device implements Frequency Spread Spectrum (FSS) with a switching frequency jitter of 6%. FSS reduces EMI by not allowing emitted energy to stay in any one frequency for a significant period of time. The converter further dampens high frequency radiated EMI noise through the use of its proprietary gate driver scheme to achieve a ringing-free switching node voltage without sacrificing the MOSFET switching times. AP63200/AP63201/AP63203/AP63205 Document number: DS41326 Rev. 2 - 2 9 of 18 www.diodes.com January 2019 (c) Diodes Incorporated AP63200/AP63201/AP63203/AP63205 Application Information (continued) In order to provide a small output ripple in light load conditions, the AP63201 offers a fixed 500kHz switching frequency with FSS and Pulse Width Modulation (PWM). The hiccup mode minimizes power dissipation during prolonged output overcurrent or short conditions. The hiccup wait time is 512 cycles and the hiccup restart time is 8192 cycles. The AP63200/AP63201/AP63203/AP63205 also features full protections including cycle-by-cycle high-side MOSFET peak current limit, overvoltage protection, and overtemperature protection. 2 Pulse Frequency Modulation In heavy load conditions, the AP63200, AP63203, and AP63205 operate at forced PWM mode. The internal COMP node voltage decreases as the load current decreases. At a certain limit, if the load current is low enough, the COMP node voltage is clamped and is prevented from decreasing any further. The voltage at which COMP is clamped corresponds to the 450mA peak inductor current. As the load current approaches zero, the AP63200, AP63203, and AP63205 enter Pulse Frequency Modulation (PFM) to increase the converter power efficiency at light load conditions. The AP63201 remains in continuous conduction mode at light load conditions. When the inductor current decreases to zero, zero-cross detection circuitry on the low-side power MOSFET, Q2, forces it off until the beginning of the next switching cycle. The buck converter does not sink current from the output when the output load is light and while the device is in PFM. Because the AP63200, AP63203, and AP63205 work in PFM during light load conditions, they can achieve power efficiency of up to 88% at a 5mA load condition. The quiescent current of AP63200, AP63203 and AP63205 is 22A typical under a no-load, non-switching condition. 3 Enable When disabled, the device shutdown supply current is only 1A. When applying a voltage higher than the EN upper threshold (typical 1.18V, rising), the AP63200/AP63201/AP63203/AP63205 enables all functions, and the device initiates the soft-start phase. The AP63200/AP63201/AP63203/AP63205 has a built-in 4ms soft-start time to prevent output voltage overshoot and inrush current. When the EN voltage falls below its lower threshold (typical 1.1V, falling), the internal SS voltage is discharged to ground and device operation is disabled. An internal 1.5A pull-up current source connected from the internal LDO-regulated VCC to the EN pin guarantees that a high on the EN pin automatically enables the device. For applications requiring a higher VIN UVLO voltage than is provided by the default setup, there is a 4A hysteresis pull-up current source on the EN pin that configures the VIN UVLO voltage with an external resistive divider (R5 and R6) shown in Figure 22. The resistive divider resistor values are calculated by equations Eq.1 and Eq.2. VIN I1 1.5A R5 EN I2 4A 20k 2 1.18V + - ON R6 Figure 22. Programming UVLO = = Where: * * . - . . - . + . Eq. 1 Eq. 2 VON is the rising edge voltage to enable the regulator VOFF is the falling edge voltage to disable the regulator AP63200/AP63201/AP63203/AP63205 Document number: DS41326 Rev. 2 - 2 10 of 18 www.diodes.com January 2019 (c) Diodes Incorporated AP63200/AP63201/AP63203/AP63205 Application Information (continued) Alternatively, a small ceramic capacitor can be added from EN to GND. This delays the output startup voltage, which is useful when sequencing multiple power rails to minimize input inrush current. The amount of capacitance is calculated by equation Eq.3. Where: * * [] = . [] Eq. 3 Cd is the time delay capacitance in nF ts is the delay time in ms The EN pin is a high voltage pin and can be directly connected to VIN to automatically start up the device as VIN increases. 4 Undervoltage Lockout Undervoltage lockout is implemented to prevent the IC from insufficient input voltages. The AP63200/AP63201/AP63203/AP63205 device has a UVLO comparator that monitors the input voltage and the internal bandgap reference. If the input voltage falls below 3.1V, the AP63200/AP63201/AP63203/AP63205 is disabled. In this event, both the high-side and low-side power MOSFETs are turned off. 5 EMI Reduction with Frequency Spread Spectrum and Ringing-free Switching Node In the some applications, the system must meet EMI standards. To improve EMI reduction, the AP63200/AP63201/AP63203/AP63205 adopts FSS to spread the switching noise over a wider frequency band and therefore reduces conducted and radiated interference at a particular frequency. In buck converters, the switching node's (SW's) ringing amplitude and cycles are critical, especially in relation to the high frequency radiation EMI noise. The AP63200/AP63201/AP63203/AP63205 device implements a multi-level gate driver scheme to achieve a ringing-free switching node without sacrificing neither the switching node's rise and fall slew rates nor the converter's power efficiency. The AP63203 and AP63205 also have the feature to remove the resonance ringing of the SW pin when the inductor current is 0A and the device operates in PFM. The zoomed in waveform for SW is shown in Figure 23. No SW Ringing SW (5V/div) IL (1A/div) 2s/div Figure 23. AP63203/AP63205 SW Node Waveform 6 Overcurrent Protection The AP63200/AP63201/AP63203/AP63205 has cycle-by-cycle peak current limit protection by sensing the current through the internal high-side power MOSFET Q1. While Q1 is on, its conduction current is monitored by the internal sensing circuitry. Once the current through Q1 exceeds the current peak limit, Q1 immediately turns off. If Q1 consistently hits the peak current limit for 2ms, the buck converter enters hiccup mode and shuts down. After 16ms of off time, the buck converter restarts powering up. Hiccup mode reduces the power dissipation in the overcurrent condition. 7 Thermal Shutdown If the junction temperature of the device reaches the thermal shutdown limit of +150C, the AP63200/AP63201/AP63203/AP63205 shuts down both their high-side and low-side power MOSFETs. When the junction temperature reduces to the required level (+130C nominal), the device initiates a normal power-up cycle with soft-start. AP63200/AP63201/AP63203/AP63205 Document number: DS41326 Rev. 2 - 2 11 of 18 www.diodes.com January 2019 (c) Diodes Incorporated AP63200/AP63201/AP63203/AP63205 Application Information (continued) 8 Power Derating Characteristics To prevent the regulator from exceeding the maximum junction temperature, some thermal analysis is required. The temperature rise is given by: = ( ) Eq. 4 = + Eq. 5 Where PD is the power dissipated by the regulator and JA is the thermal resistance from the junction of the die to the ambient temperature. The junction temperature, TJ, is given by: Where TA is the ambient temperature of the environment. For the TSOT26 package, the JA is 89C/W. The actual junction temperature should not exceed the absolute maximum junction temperature of +125C when considering the thermal design. A typical derating curve versus ambient temperature is shown in Figure 24. Figure 24. Output Current Derating Curve vs. Temperature, VIN = 12V 9 Setting the Output Voltage The AP63203 and AP63205 have fixed output voltages of 3.3V and 5V, respectively. The AP63200 and AP63201 have adjustable output voltages starting from 0.8V using an external resistive divider. An optional in Figure 20, of 10pF to 220pF is used to improve the transient response. Resistor R2 is selected based on a design tradeoff between efficiency and output voltage accuracy. There is less current consumption in the feedback network for high values of R2. R1 can be determined by the following equation: = ( AP63200/AP63201/AP63203/AP63205 Document number: DS41326 Rev. 2 - 2 . - ) 12 of 18 www.diodes.com Eq. 6 January 2019 (c) Diodes Incorporated AP63200/AP63201/AP63203/AP63205 Application Information (continued) Table 1 shows a list of recommended component selections for common output voltages for AP6300 and AP63201 referencing Figure 20. Output Voltage (V) 1.2 1.5 1.8 2.5 3.3 5 12 AP63200/AP63201 L (H) R2 (k) 62 2.2 62 2.2 62 3.3 62 3.3 62 6.8 30 10 18 10 R1 (k) 30.9 54.2 77.5 131 182 157 249 C1 (F) 10 10 10 10 10 10 10 C2 (F) 2 x 22 2 x 22 2 x 22 2 x 22 2 x 22 2 x 22 2 x 22 C3 (nF) 100 100 100 100 100 100 100 C4 (pF) 100 100 100 100 100 100 56 Table 1. Recommended Component Selections for AP63200/AP63201 Tables 2 and 3 show recommended component selections for AP63203 and AP63205 referencing Figure 21. Output Voltage (V) 3.3 AP63203 C1 (F) 10 L (H) 3.9 C2 (F) 2 x 22 C3 (nF) 100 Table 2. Recommended Component Selections for AP63203 Output Voltage (V) 5 AP63205 C1 (F) 10 L (H) 4.7 C2 (F) 2 x 22 C3 (nF) 100 Table 3. Recommended Component Selections for AP63205 10 Inductor Calculating the inductor value is a critical factor in designing a buck converter. For most designs, the following equation can be used to calculate the inductor value: = ( - ) Eq. 7 Where IL is the inductor ripple current, and fSW is the buck converter switching frequency. For AP63200/AP63201/AP63203/AP63205, choose IL to be 30% to 50% of the maximum load current of 2A. The inductor peak current is calculated by: = + Eq. 8 Peak current determines the required saturation current rating, which influences the size of the inductor. Saturating the inductor decreases the converter efficiency while increasing the temperatures of the inductor and the internal power MOSFETs. Therefore, choosing an inductor with the appropriate saturation current rating is important. For most applications, it is recommended to select an inductor of approximately 2.2H to 10H with a DC current rating of at least 35% higher than the maximum load current. For highest efficiency, the inductor's DC resistance should be less than 100m. Use a larger inductance for improved efficiency under light load conditions. 11 Input Capacitor The input capacitor reduces the surge current drawn from the input supply as well as the switching noise from the device. The input capacitor has to sustain the ripple current produced during the on time of Q1. It must have a low ESR to minimize the losses. The RMS current rating of the input capacitor is a critical parameter and must be higher than the RMS input current. As a rule of thumb, select an input capacitor which has an RMS rating greater than half of the maximum load current. Due to large dI/dt through the input capacitor, electrolytic, or ceramics with low ESR should be used. If a tantalum capacitor is used it must be surge protected or else capacitor failure could occur. Using a ceramic capacitor greater than 10F is sufficient for most applications. AP63200/AP63201/AP63203/AP63205 Document number: DS41326 Rev. 2 - 2 13 of 18 www.diodes.com January 2019 (c) Diodes Incorporated AP63200/AP63201/AP63203/AP63205 Application Information (continued) 12 Output Capacitor The output capacitor keeps the output voltage ripple small, ensures feedback loop stability, and reduces the overshoot/undershoot of the output voltage during load transients. During the first few milliseconds of a load transient, the output capacitor supplies the current to the load. The converter recognizes the load transient and sets the duty cycle to maximum but the current slope is limited by the inductor value. The output capacitor, COUT, requirements can be calculated from equations Eq. 9 and Eq. 10. The ESR of the output capacitor dominates the output voltage ripple. The amount of ripple can be calculated from Eq. 9: = Eq. 9 An output capacitor with large capacitance and low ESR is the best option. For most applications, a 22F to 68F ceramic capacitor is sufficient. To meet the load transient requirement, COUT should be greater than the following calculated from Eq. 10: + > (+ ) - Eq. 10 Where V is the maximum output overshoot voltage. 13 Bootstrap Capacitor To ensure the proper operation, a ceramic capacitor must be connected between the BST and SW pins. A 100nF ceramic capacitor is sufficient. If the BST capacitor voltage falls below 2.3V, the boot undervoltage protection circuit turns Q2 on for 220ns to refresh the BST capacitor and raise its voltage back above 2.85V. The BST capacitor voltage threshold is always maintained to ensure enough driving capability for Q1. This operation may arise during long periods of no switching such as in PFM with light load conditions. Another event requires the refreshing of the BST capacitor is when the input voltage drops close to the output voltage. Under this condition, the regulator enters low dropout mode by holding Q1 on for multiple clock cycles. To prevent the BST capacitor from discharging, Q2 is forced to refresh. The effective duty cycle is approximately 100% so that it acts as an LDO to maintain the output voltage regulation. AP63200/AP63201/AP63203/AP63205 Document number: DS41326 Rev. 2 - 2 14 of 18 www.diodes.com January 2019 (c) Diodes Incorporated AP63200/AP63201/AP63203/AP63205 Layout PCB Layout 1. 2. 3. 4. 5. 6. The AP63200/AP63201/AP63203/AP63205 device works at 2A current load, so heat dissipation is a major concern in the layout of the PCB. 2oz copper for both the top and bottom layers is recommended. Provide sufficient vias for the input and output capacitors' GND side to dissipate heat to the bottom layer. Make the bottom layer under the device as the GND layer for heat dissipation. The GND layer should be as large as possible to provide better thermal effect. Place the VIN capacitors as close to the device as possible. Place the feedback components as close to FB as possible. See Figure 25 for reference. C3 R1 C4 R2 FB 1 6 BST EN 2 5 SW VIN 3 4 GND SW C1 VIN L1 C2 GND VOUT Figure 25. Recommended Layout AP63200/AP63201/AP63203/AP63205 Document number: DS41326 Rev. 2 - 2 15 of 18 www.diodes.com January 2019 (c) Diodes Incorporated AP63200/AP63201/AP63203/AP63205 Ordering Information Please see http://www.diodes.com/package-outlines.html for additional latest information such as Mechanical Data and Device Tape Orientation. AP6320X XX - X Product Version Package Packing 0: AP63200 1: AP63201 3: AP63203 5: AP63205 WU : TSOT26 7 : Tape & Reel Part Number Mode Frequency VOUT Package Code AP63200WU-7 AP63201WU-7 AP63203WU-7 AP63205WU-7 PWM/PFM PWM Only PWM/PFM PWM/PFM 500kHz 500kHz 1100kHz 1100kHz Adjustable Adjustable 3.3V 5V WU WU WU WU Tape and Reel Quantity Part Number Suffix 3000 3000 3000 3000 -7 -7 -7 -7 Marking Information TSOT26 (Top View) 5 4 7 6 XX Y W X 1 3 Part Number Package Identification Code AP63200WU-7 AP63201WU-7 AP63203WU-7 AP63205WU-7 TSOT26 TSOT26 TSOT26 TSOT26 T2 T3 T4 T5 AP63200/AP63201/AP63203/AP63205 Document number: DS41326 Rev. 2 - 2 2 XX : Identification Code Y : Year 0~9 W : Week : A~Z : 1~26 week; a~z : 27~52 week; z represents 52 and 53 week X : Internal Code 16 of 18 www.diodes.com January 2019 (c) Diodes Incorporated AP63200/AP63201/AP63203/AP63205 Package Outline Dimensions Please see http://www.diodes.com/package-outlines.html for the latest version. TSOT26 D e1 01( 4x) E1/2 E/2 E1 c E Gauge Plane 0 L 01( 4x) b e L2 A2 A1 A Seating Plane Seating Plane TSOT26 Dim Min Max Typ A 1.00 -- A1 0.010 0.100 -- A2 0.840 0.900 -- D 2.800 3.000 2.900 E 2.800 BSC E1 1.500 1.700 1.600 b 0.300 0.450 -- c 0.120 0.200 -- e 0.950 BSC e1 1.900 BSC L 0.30 0.50 -- L2 0.250 BSC 0 8 4 1 4 12 -- All Dimensions in mm Suggested Pad Layout Please see http://www.diodes.com/package-outlines.html for the latest version. TSOT26 C Dimensions Value (in mm) C 0.950 X 0.700 Y 1.000 Y1 3.199 Y1 Y X AP63200/AP63201/AP63203/AP63205 Document number: DS41326 Rev. 2 - 2 17 of 18 www.diodes.com January 2019 (c) Diodes Incorporated AP63200/AP63201/AP63203/AP63205 IMPORTANT NOTICE DIODES INCORPORATED MAKES NO WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, WITH REGARDS TO THIS DOCUMENT, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE (AND THEIR EQUIVALENTS UNDER THE LAWS OF ANY JURISDICTION). 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Should Customers purchase or use Diodes Incorporated products for any unintended or unauthorized application, Customers shall indemnify and hold Diodes Incorporated and its representatives harmless against all claims, damages, expenses, and attorney fees arising out of, directly or indirectly, any claim of personal injury or death associated with such unintended or unauthorized application. Products described herein may be covered by one or more United States, international or foreign patents pending. Product names and markings noted herein may also be covered by one or more United States, international or foreign trademarks. This document is written in English but may be translated into multiple languages for reference. Only the English version of this document is the final and determinative format released by Diodes Incorporated. LIFE SUPPORT Diodes Incorporated products are specifically not authorized for use as critical components in life support devices or systems without the express written approval of the Chief Executive Officer of Diodes Incorporated. As used herein: A. Life support devices or systems are devices or systems which: 1. are intended to implant into the body, or 2. support or sustain life and whose failure to perform when properly used in accordance with instructions for use provided in the labeling can be reasonably expected to result in significant injury to the user. B. A critical component is any component in a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or to affect its safety or effectiveness. Customers represent that they have all necessary expertise in the safety and regulatory ramifications of their life support devices or systems, and acknowledge and agree that they are solely responsible for all legal, regulatory and safety-related requirements concerning their products and any use of Diodes Incorporated products in such safety-critical, life support devices or systems, notwithstanding any devices- or systems-related information or support that may be provided by Diodes Incorporated. Further, Customers must fully indemnify Diodes Incorporated and its representatives against any damages arising out of the use of Diodes Incorporated products in such safety-critical, life support devices or systems. Copyright (c) 2019, Diodes Incorporated www.diodes.com AP63200/AP63201/AP63203/AP63205 Document number: DS41326 Rev. 2 - 2 18 of 18 www.diodes.com January 2019 (c) Diodes Incorporated