FAN48630 — 2.5 MHz, 1500 mA, Synchronous TinyBoost™ Regulator with Bypass Mode Features Description Few External Components: 0.47 µH Inductor and 0603 Case Size Input and Output Capacitors Input Voltage Range: 2.35 V to 5.5 V The FAN48630 allows systems to take advantage of new battery chemistries that can supply significant energy when the battery voltage is lower than the required voltage for system power ICs. By combining built-in power transistors, synchronous rectification, and low supply current; this IC provides a compact solution for systems using advanced Li-Ion battery chemistries. Up to 96% Efficient Fixed Output Voltage Options: 3.0 V to 5.0 V Maximum Continuous Load Current: 1500 mA at VIN of 2.6 V Boosting VOUT to 3.5 V The FAN48630 is a boost regulator designed to provide a minimum output voltage (VOUT(MIN)) from a single-cell Li-Ion battery, even when the battery voltage is below system minimum. Output voltage regulation is guaranteed to a maximum load current of 1500 mA. Quiescent current in Shutdown Mode is less than 3 µA, which maximizes battery life. The regulator transitions smoothly between Bypass and normal Boost Mode. The device can be forced into Bypass Mode to reduce quiescent current. True Bypass Operation when VIN > Target VOUT Internal Synchronous Rectifier Soft-Start with True Load Disconnect Forced Bypass Mode VSEL Control to Optimize Target VOUT The FAN48630 is available in a 16-bump, 0.4 mm pitch, Wafer-Level Chip-Scale Package (WLCSP). Short-Circuit Protection Low Operating Quiescent Current 16-Bump, 0.4 mm Pitch WLCSP L1 Applications Boost for Low-Voltage Li-ion Batteries, Brownout Prevention, Boosted Audio, USB OTG, and LTE / 3G RF Power Cell Phones, Smart Phones, Portable Instruments Figure 1. Typical Application Ordering Information Part Number Output Voltage(1) VSEL0 / VSEL1 SoftStart Forced Bypass FAN48630UC315X 3.15 / 3.33 FAST Low IQ FAN48630UC33X 3.30 / 3.49 FAST Low IQ FAN48630UC35X 3.50 / 3.70 FAST Low IQ FAN48630UC37AX 3.70 / 3.77 FAST Low IQ FAN48630UC45X 4.50 / 4.76 SLOW OCP On FAN48630UC50X 5.00 / 5.29 SLOW OCP On Operating Temperature Package(2) Packing -40°C to 85°C 16-Ball, 4x4 Array, 0.4 mm Pitch, 250 µm Ball, Wafer-Level ChipScale Package (WLCSP) Tape and Reel Notes: 1. Other output voltages are available on request. Please contact a Fairchild Semiconductor representative. 2. Includes backside laminate. © 2011 Fairchild Semiconductor Corporation FAN48630 • Rev. 1.0.1 www.fairchildsemi.com FAN48630 — 2.5MHz, 1500mA Synchronous TinyBoost™ Regulator with Bypass Mode November 2012 Q3B Q3A VIN CIN Q3 L1 BYPASS CONTROL Q1B Q1A SW VOUT Q2 GND Q1 COUT Synchronous Rectifier Control VSEL EN BYP MODULATOR LOGIC AND CONTROL PG Figure 2. Block Diagram Table 1. Recommended Components Component Description Vendor Parameter Typ. Unit 0.47 µH 0.47 µH, 30% Toko: DFE201612C DFR201612C Cyntec: PIFE20161B L L1 DCR (Series R) 40 m CIN 4.7 µF, 10%, 6.3 V, X5R, 0603 Murata: GRM188R60J475K TDK: C1608X5R0J475K C 4.7 µF COUT 2 x 10 µF, 20%, 10 V, X5R, 0603 TDK: C1608X5R1A106M C 20 µF © 2011 Fairchild Semiconductor Corporation FAN48630 • Rev. 1.0.1 www.fairchildsemi.com 2 FAN48630 — 2.5MHz, 1500mA Synchronous TinyBoost™ Regulator with Bypass Mode Block Diagram EN PG A1 A2 VSEL AGND B1 VIN VOUT B2 B3 C2 C3 AGND D1 B4 SW BYP C1 A4 A3 C4 PGND D2 D3 D4 Figure 3. Top Through View (Bumps Down) Figure 4. Bottom View (Bumps Up) Pin Definitions Pin # Name Description A1 EN Enable. When this pin is HIGH, the circuit is enabled. A2 PG Power Good. This is an open-drain output. PG is actively pulled LOW if output falls out of regulation due to overload or if thermal protection threshold is exceeded. A3–A4 VIN Input Voltage. Connect to Li-Ion battery input power source. B1 VSEL Output Voltage Select. When boost is running, this pin can be used to select output voltage. B2, C2 D1 AGND Analog Ground. This is the signal ground reference for the IC. All voltage levels are measured with respect to this pin. B3–B4 VOUT Output Voltage. Place COUT as close as possible to the device. C1 BYP Bypass. This pin can be used to activate Forced Bypass Mode. When this pin is LOW, the bypass switches (Q3 and Q1) are turned on and the IC is otherwise inactive. C3–C4 SW Switching Node. Connect to inductor. D2–D4 PGND Power Ground. This is the power return for the IC. The COUT bypass capacitor should be returned with the shortest path possible to these pins. © 2011 Fairchild Semiconductor Corporation FAN48630 • Rev. 1.0.1 www.fairchildsemi.com 3 FAN48630 — 2.5MHz, 1500mA Synchronous TinyBoost™ Regulator with Bypass Mode Pin Configuration Stresses exceeding the absolute maximum ratings may damage the device. The device may not function or be operable above the recommended operating conditions and stressing the parts to these levels is not recommended. In addition, extended exposure to stresses above the recommended operating conditions may affect device reliability. The absolute maximum ratings are stress ratings only. Symbol VIN VOUT Parameter VIN Input Voltage Min. Max. Unit -0.3 6.5 V 6.0 V 8.0 V VOUT Output Voltage SW Node DC -0.3 Transient: 10 ns, 3 MHz Other Pins -1.0 8.0 V -0.3 6.5(3) V Human Body Model per JESD22-A114 3.0 kV ESD Electrostatic Discharge Protection Level TJ Junction Temperature –40 +150 °C TSTG Storage Temperature –65 +150 °C +260 °C TL Charged Device Model per JESD22-C101 1.5 Lead Soldering Temperature, 10 Seconds kV Note: 3. Lesser of 6.5 V or VIN + 0.3 V. Recommended Operating Conditions The Recommended Operating Conditions table defines the conditions for actual device operation. Recommended operating conditions are specified to ensure optimal performance to the datasheet specifications. Fairchild does not recommend exceeding them or designing to absolute maximum ratings. Symbol VIN IOUT Parameter Supply Voltage Output Current Min. Max. Unit 2.35 5.50 V 0 1500 mA TA Ambient Temperature –40 +85 °C TJ Junction Temperature –40 +125 °C Thermal Properties Junction-to-ambient thermal resistance is a function of application and board layout. This data is measured with four-layer Fairchild evaluation boards (1 oz copper on all layers). Special attention must be paid not to exceed junction temperature TJ(max) at a given ambient temperate TA. Symbol Parameter Typical JA Junction-to-Ambient Thermal Resistance 80 JB Junction-to-Board Thermal Resistance 42 © 2011 Fairchild Semiconductor Corporation FAN48630 • Rev. 1.0.1 Unit °C/W www.fairchildsemi.com 4 FAN48630 — 2.5MHz, 1500mA Synchronous TinyBoost™ Regulator with Bypass Mode Absolute Maximum Ratings Recommended operating conditions, unless otherwise noted, circuit per Figure 1, VIN = 2.35 V to VOUT, TA = -40˚C to 85˚C. Typical values are given VIN = 3.0 V and TA = 25˚C. Symbol IQ Parameter VIN Quiescent Current Conditions Typ. Max. Bypass Mode VOUT=3.5 V, VIN=4.2 V 140 190 A Boost Mode VOUT=3.5 V, VIN=2.5 V 150 250 A Shutdown: EN=0, VIN=3.0 V 1.5 5.0 A Low IQ 4 10 A OCP On 45 90 A Forced Bypass Mode VOUT=3.5 V, VIN=3.5 V ILK ILK_OUT VUVLO VUVLO_HYS Min. Unit VOUT to VIN Reverse Leakage VOUT=5 V, EN=0 0.2 1.0 A VOUT Leakage Current VOUT=0, EN=0, VIN=4.2 V 0.1 1.0 A Under-Voltage Lockout VIN Rising 2.20 2.35 Under-Voltage Lockout Hysteresis 200 V mV VPG(OL) PG Low IPG=5 mA 0.4 V IPG_LK PG Leakage Current VPG=5 V 1 µA VIH Logic Level HIGH EN, VSEL, BYP VIL Logic Level LOW EN, VSEL, BYP 1.2 V 0.4 V Logic Control Pin Pull Downs (LOW Active) BYP, VSEL, EN 300 k Weak Current Source Pull-Down BYP, VSEL, EN 100 nA VREG Output Voltage Accuracy Referred to GND, DC, VOUT-VIN > 100 mV VTRSP Load Transient Response 500 – 1250 mA, VIN=3.6 V, VOUT=5.0 V ±4 % tON On-Time VIN=3.0 V, VOUT=3.5 V, Load >1000 mA 80 ns fSW Switching Frequency VIN=3.6 V, VOUT=5.0 V, Load=1000 mA 2.0 2.5 3.0 MHz Boost Valley Current Limit VIN=2.6 V 2.6 2.9 3.1 A Boost Valley Current Limit During SS VIN=2.6 V 1.6 A VOUT=5.0 V, TJ < 120˚C 3.0 V VOUT=4.5 V, TJ < 120˚C 2.8 V VOUT=3.5 V, TJ < 120˚C 2.35 V VOUT=3.15 V, TJ < 120˚C 2.35 V RLOW IPD IV_LIM IV_LIM_SS VMIN_1.5A Minimum VIN for 1500 mA Load (Short Term) 350 mA 800 mA Slow 700 mA Fast 1600 mA Slow, 50 Load 1300 s Fast, 50 Load 600 s VIN=5.0 V, VIN-VOUT 200 mV Soft-Start Input Peak Current Limit Soft-Start EN HIGH to Regulation % Slow LIN2 tSS 4 Fast LIN1 ISS_PK –2 VOCP OCP Comparator Threshold VOVP Output Over-Voltage Protection Threshold 6.0 VOVP_HYS Output Over-Voltage Protection Hysteresis 300 6.3 V mV Continued on the following page… © 2011 Fairchild Semiconductor Corporation FAN48630 • Rev. 1.0.1 www.fairchildsemi.com 5 FAN48630 — 2.5MHz, 1500mA Synchronous TinyBoost™ Regulator with Bypass Mode Electrical Specifications Recommended operating conditions, unless otherwise noted, circuit per Figure 1, VIN = 2.35 V to VOUT, TA = -40˚C to 85˚C. Typical values are given VIN = 3.0 V and TA = 25˚C. Symbol Parameter Conditions Min. Typ. Max. Unit RDS(ON)N N-Channel Boost Switch RDS(ON) VIN=3.5 V, VOUT=3.5 V 85 120 mΩ RDS(ON)P P-Channel Sync Rectifier RDS(ON) VIN=3.5 V, VOUT=3.5 V 65 85 mΩ 65 85 mΩ RDS(ON)P_BYP P-Channel Bypass Switch RDS(ON) VIN=3.5 V, VOUT=3.5 V T120A T120 Activation Threshold 120 °C T120R T120 Release Threshold 100 °C T150T T150 Threshold 150 °C T150H T150 Hysteresis 20 °C tRST FAULT Restart Timer 20 ms © 2011 Fairchild Semiconductor Corporation FAN48630 • Rev. 1.0.1 www.fairchildsemi.com 6 FAN48630 — 2.5MHz, 1500mA Synchronous TinyBoost™ Regulator with Bypass Mode Electrical Specifications (Continued) Unless otherwise specified; VIN = 3.6 V, and VOUT = 5 V, and TA = 25°C; circuit and components according to Figure 1. 100% 96% 94% 96% 92% Efficiency Efficiency 92% 88% 2.5 VIN 3.0 VIN 84% 90% 88% 86% 84% - 40C 3.3 VIN 82% 4.2 VIN +25C +85C 80% 80% 0 250 500 750 1000 1250 0 1500 250 500 750 1000 1250 1500 Load Current (mA) Load Current (mA) Figure 5. Efficiency vs. Load Current and Input Voltage, VOUT=3.5 V Figure 6. Efficiency vs. Load Current and Temperature, VIN=3.0V, VOUT=3.5 V 96% 96% 92% 92% Efficiency Efficiency 88% 84% 88% 84% 80% 2.5 VIN - 40C 80% 3.0 VIN 76% 3.6 VIN +25C 4.2 VIN 72% 0 250 500 750 1000 1250 +85C 76% 1500 0 250 Load Current (mA) 500 750 1000 1250 1500 Load Current (mA) Figure 7. Efficiency vs. Load Current and Input Voltage Figure 8. Efficiency vs. Load Current and Temperature 100% 100% 96% 96% Efficiency Efficiency 92% 92% 88% 88% 84% 5.0 VOUT 5.0 VOUT 84% 4.5 VOUT 4.5 VOUT 80% 3.5 VOUT 3.5 VOUT 3.15 VOUT 3.15 VOUT 80% 2.0 2.5 3.0 3.5 4.0 76% 4.5 2.0 Input Voltage (V) 2.5 3.0 3.5 4.0 4.5 Input Voltage (V) Figure 9. Efficiency vs. Input Voltage and Output Voltage, Figure 10. Efficiency vs. Input Voltage and Output Voltage, 200 mA Load 1000 mA Load © 2011 Fairchild Semiconductor Corporation FAN48630 • Rev. 1.0.1 www.fairchildsemi.com 7 FAN48630 — 2.5MHz, 1500mA Synchronous TinyBoost™ Regulator with Bypass Mode Typical Characteristics 3 3 2 2 Output Regulation (%) Output Regulation (%) Unless otherwise specified; VIN = 3.6 V, VOUT = 5 V, and TA = 25°C; circuit and components according to Figure 1. 1 0 2.5 VIN 3.0 VIN -1 1 0 - 40C -1 3.6 VIN +25C 4.2 VIN -2 +85C -2 0 250 500 750 1000 1250 1500 0 250 Load Current (mA) 1250 1500 - 40C Auto +25C Auto +85C Auto - 40C Bypass +25C Bypass +85C Bypass 200 Input Current (A) Input Current (A) 250 150 100 50 150 100 50 0 0 2.0 2.5 3.0 3.5 4.0 4.5 2.0 2.5 Input Voltage (V) 3.0 3.5 4.0 Figure 14. Quiescent Current vs. Input Voltage, Temperature and Mode, VOUT=3.5 V, Forced Bypass, Low IQ 3,000 50 2,500 Switching Frequency (KHz) 60 40 30 20 2.5 VIN 3.0 VIN 10 3.6 VIN 2,000 1,500 1,000 2.5 VIN 3.0 VIN 500 3.6 VIN 4.2 VIN 0 0 250 500 750 1000 1250 4.2 VIN 0 1500 0 Load Current (mA) 250 500 750 1000 1250 1500 Load Current (mA) Figure 15. Output Ripple vs. Load Current and Input Voltage © 2011 Fairchild Semiconductor Corporation FAN48630 • Rev. 1.0.1 4.5 Input Voltage (V) Figure 13. Quiescent Current vs. Input Voltage, Temperature and Mode, VOUT=5.0 V, Forced Bypass, OCP Active Output Ripple (mVpp) 1000 Figure 12. Output Regulation vs. Load Current and Temperature (Normalized to 3.6 VIN, 500 mA Load, TA=25°C) - 40C Auto +25C Auto +85C Auto - 40C Bypass +25C Bypass +85C Bypass 200 750 Load Current (mA) Figure 11. Output Regulation vs. Load Current and Input Voltage (Normalized to 3.6 VIN, 500 mA Load) 250 500 Figure 16. Frequency vs. Load Current and Input Voltage www.fairchildsemi.com 8 FAN48630 — 2.5MHz, 1500mA Synchronous TinyBoost™ Regulator with Bypass Mode Typical Characteristics (Continued) Unless otherwise specified, VIN = 3.6 V; VOUT = 5 V, and TA = 25°C; circuit and components according to Figure 1. Figure 17. Startup, 50 Ω Load Figure 18. Startup, 50 Load, VIN=2.5 V, VOUT=3.5 V Figure 19. Overload Protection Figure 20. Load Transient, 100-500 mA, 100 ns Edge Figure 21. Load Transient, 500-1250 mA, 100 ns Edge Figure 22. Load Transient, 100-500 mA, 100 ns Edge, VIN=3 V, VOUT=3.5 V © 2011 Fairchild Semiconductor Corporation FAN48630 • Rev. 1.0.1 www.fairchildsemi.com 9 FAN48630 — 2.5MHz, 1500mA Synchronous TinyBoost™ Regulator with Bypass Mode Typical Characteristics (Continued) Unless otherwise specified, VIN = 3.6 V, VOUT = 5 V, TA = 25°C; circuit and components according to Figure 1. Figure 23. Load Transient, 500-1950 mA, 100 ns Edge, VIN=3 V, VOUT=3.5 V Figure. 24 Line Transient, 3.0-3.6 VIN, 10 µs Edge, 500 mA Load, VOUT=3.15 V Figure 25. Line Transient, 3.0-3.6 VIN, 10 µs Edge, 1,000 mA Load, VOUT=3.5 V Figure 26. Line Transient, 3.3-3.9 VIN, 10 µs Edge, 500 mA load, VOUT=3.5 V Figure. 27 Bypass Entry / Exit, Slow VIN Ramp 1 ms Edge, 500 mA Load, VOUT=3.5 V, 3.2 - 3.8 VIN Figure 28. VSEL Step, VIN=3 V, VOUT=3.5 V, 500 mA Load © 2011 Fairchild Semiconductor Corporation FAN48630 • Rev. 1.0.1 www.fairchildsemi.com 10 FAN48630 — 2.5MHz, 1500mA Synchronous TinyBoost™ Regulator with Bypass Mode Typical Characteristics (Continued) FAN48630 is a synchronous boost regulator, typically operating at 2.5 MHz in Continuous Conduction Mode (CCM), which occurs at moderate to heavy load current and low VIN voltages. The regulator includes a Bypass Mode that activates when VIN is above the boost regulator’s setpoint. In LIN2 Mode, the current source is incremented to 2A. If VOUT fails to reach VIN-300 mV after 1024 s, a fault condition is declared. SS State Upon the successful completion of the LIN state (VOUT>VIN300 mV), the regulator begins switching with boost pulses current limited to 50% of nominal level. In anticipation of a heavy load transition, the setpoint can be adjusted upward by fixed amounts with the VSEL pin to reduce the required system headroom during lighter-load operation to save power. During SS state, VOUT is ramped up by stepping the internal reference. If VOUT fails to reach regulation during the SS ramp sequence for more than 64 µs, a fault condition is declared. If large COUT is used, the reference is automatically stepped slower to avoid excessive input current draw. Table 2. Operating States Mode Description Invoked When LIN Linear Startup VIN > VOUT SS Boost Soft-Start VOUT < VOUT(MIN) This is a normal operating state of the regulator. BST Boost Operating Mode VOUT = VOUT(MIN) BPS State BPS True Bypass Mode VIN > VOUT(MIN) BST State If VIN is above VREG when the SS Mode successfully completes, the device transitions directly to BPS Mode. Boost Mode FAST and SLOW Soft-Start Options The FAN48630 uses a current-mode modulator to achieve excellent transient response and smooth transitions between CCM and Discontinuous Conduction Mode (DCM) operation. During CCM operation, the device maintains a switching frequency of about 2.5 Mhz. In light-load operation (DCM), frequency is reduced to maintain high efficiency. FAN48630UC315X, FAN48630UC33X, FAN48630UC35X, and FAN48630UC37AX feature fast startup with EN to regulation time of 500 µs. LIN1 and LIN2 phase currents are doubled compared to SLOW options, SS phase is also faster. Table 3. FAN48630UC45X and FAN48630UC50XS feature low startup with EN to regulation time of 1300 s to reduce inrush current. Boost Startup Sequence Start State Entry Exit End State LIN1 VIN > UVLO, EN=1 VOUT > VIN300 mV SS LIN2 LIN2 SS LIN1 Exit LIN1 or LIN2 Exit VOUT > VIN300 mV SS TIMEOUT FAULT VOUT=VOUT(MIN) BST OVERLOAD TIMEOUT FAULT FAULT State Timeout (µs) The regulator enters the FAULT state under any of the following conditions: VOUT fails to achieve the voltage required to advance from LIN state to SS state. 512 VOUT fails to achieve the voltage required to advance from SS state to BST state. 1024 Boost current limit triggers for 2 ms during the BST state. VDS protection threshold is exceeded during BPS state. Once a fault is triggered, the regulator stops switching and presents a high-impedance path between VIN and VOUT. After waiting 20 ms, a restart is attempted. 64 Power Good Shutdown and Startup Power good is 0 FAULT, 1 POWER GOOD, open-drain input. The Power good pin is provided for signaling the system when the regulator has successfully completed soft-start and no faults have occurred. Power good also functions as an early warning flag for high die temperature and overload conditions. If EN is LOW, all bias circuits are off and the regulator is in Shutdown Mode. During shutdown, current flow is prevented from VIN to VOUT, as well as reverse flow from VOUT to VIN. During startup, it is recommended to keep DC current draw below 500 mA. PG is released HIGH when the soft-start sequence is successfully completed. When EN is HIGH and VIN > UVLO, the regulator attempts to bring VOUT within 300 mV of VIN using the internal fixed current source from VIN (Q3). The current is limited to LIN1 set point. PG is pulled LOW when PMOS current limit has triggered for 64 µs OR the die the temperature exceeds 120°C. PG is re-asserted when the device cools below to 100°C. If VOUT reaches VIN-300 mV during LIN1 Mode, the SS state is initiated. Otherwise, LIN1 times out after 512 s and LIN2 Mode is entered. Any FAULT condition causes PG to be de-asserted. LIN State © 2011 Fairchild Semiconductor Corporation FAN48630 • Rev. 1.0.1 www.fairchildsemi.com 11 FAN48630 — 2.5MHz, 1500mA Synchronous TinyBoost™ Regulator with Bypass Mode Circuit Description The regulator shuts down when the die temperature exceeds 150°C. Restart occurs when the IC has cooled by approximately 20°C. Bypass Operation OCP in Forced Bypass Mode is available for FAN48630UC45X and FAN48630UC50X. During Forced Bypass Mode, the device is short-circuit protected by a voltage comparator tracking the voltage drop from VIN to VOUT. If the drop exceeds 200 mV, a FAULT is declared. The over-temperature protection is also active. In normal operation, the device automatically transitions from Boost Mode to Bypass Mode, if VIN goes above target VOUT. In Bypass Mode, the device fully enhances both Q1 and Q3 to provide a very low impedance path from VIN to VOUT. Entry to the Bypass Mode is triggered by condition where VIN > VOUT and no switching has occurred during past 5 µs. To soften the entry to Bypass Mode, Q3 is driven as a linear current source for the first 5 µs. Bypass Mode exit is triggered when VOUT reaches the target VOUT voltage. During Automatic Bypass Mode, the device is short-circuit protected by voltage comparator tracking the voltage drop from VIN to VOUT; if the drop exceeds 200 mV, FAULT is declared. In Forced Bypass Mode, VOUT can follow VIN below VOUT(MIN). VSEL VSEL can be asserted in anticipation of a positive load transient. Raising VSEL increases VOUT(MIN) by a fixed amount and VOUT is stepped to the corresponding target output voltage in 20 µs. The functionality can also be utilized to mitigate undershoot during severe line transients, while minimizing VOUT during more benign operating conditions to save power. Forced Bypass Entry to Forced Bypass Mode initiates with a current limit on Q3 and then proceeds to a true bypass state. To prevent reverse current to the battery, the device waits until output discharges below VIN before entering Forced Bypass Mode. © 2011 Fairchild Semiconductor Corporation FAN48630 • Rev. 1.0.1 www.fairchildsemi.com 12 FAN48630 — 2.5MHz, 1500mA Synchronous TinyBoost™ Regulator with Bypass Mode Low-IQ Forced Bypass Mode is available for FAN48630UC315X, FAN48630UC33X, FAN48630UC35X, and FAN48630UC37AX. After the transition is complete, most of the internal circuitry is disabled to minimize quiescent current draw. Short-circuit, UVLO, output OVP and overtemperature protections are inactive in Forced Bypass Mode. Over-Temperature Output Capacitance (COUT) VRIPPLE ( P P ) tON Stability The effective capacitance (CEFF) of small, high-value, ceramic capacitors decreases as bias voltage increases. FAN48630 is guaranteed for stable operation with the minimum value of CEFF (CEFF(MIN)) outlined in Table 4 below. and Table 4. therefore: VOUT (V) ILOAD (mA) CEFF(MIN) (F) 3.15 0 to 1500 12 3.5 0 to 1500 9 4.5 and 5 0 to 1500 6 EQ. 1 V tON t SW D t SW 1 IN VOUT Minimum CEFF Required for Stability Operating Conditions I LOAD COUT V VRIPPLE ( P P ) t SW 1 IN VOUT EQ. 2 I LOAD COUT EQ. 3 and t SW CEFF varies with manufacturer, material, and case size. 1 EQ. 4 f SW As can be seen from EQ. 3, the maximum VRIPPLE occurs when VIN is minimum and ILOAD is maximum. Inductor selection Recommended nominal inductance value is 0.47 H. Layout Recommendations FAN48630 employs valley-current limiting; peak inductor current can reach 3.8 A for a short duration during overload conditions. Saturation effects cause the inductor current ripple to become higher under high loading as only valley of the inductor current ripple is controlled. The layout recommendations below highlight various topcopper pours using different colors. To minimize spikes at VOUT, COUT must be placed as close as possible to PGND and VOUT, as shown in Figure 29. For FAN48630UC315X and FAN48630UC33X, a 0.33 H inductor can be used for improved transient performance. For thermal reasons, it is suggested to maximize the pour area for all planes other than SW. Especially the ground pour should be set to fill all available PCB surface area and tied to internal layers with a cluster of thermal vias. Startup Input current limiting is in effect during soft-start, which limits the current available to charge COUT and any additional capacitance on the VOUT line. If the output fails to achieve regulation within the limits described in the Startup section, a FAULT occurs, causing the circuit to shut down then restart after a significant time period. If the total combined output capacitance is very high, the circuit may not start on the first attempt, but eventually achieves regulation if no load is present. If a high-current load and high capacitance are both present during soft-start, the circuit may fail to achieve regulation and continually attempts soft-start, only to have the output capacitance discharged by the load when in a FAULT state. VIN VOUT SW Output Voltage Ripple Output voltage ripple is inversely proportional to COUT. During tON, when the boost switch is on, all load current is supplied by COUT. Output ripple is calculated as: GND Figure 29. Layout Recommendation © 2011 Fairchild Semiconductor Corporation FAN48630 • Rev. 1.0.1 www.fairchildsemi.com 13 FAN48630 — 2.5MHz, 1500mA Synchronous TinyBoost™ Regulator with Bypass Mode Application Information 0.03 C 2X E F A B 0.40 A1 BALL A1 INDEX AREA (Ø0.20) Cu Pad D 0.40 (Ø0.30) Solder Mask Opening 0.03 C 2X RECOMMENDED LAND PATTERN (NSMD PAD TYPE) TOP VIEW 0.06 C 0.625 0.547 0.05 C C SEATING PLANE 0.378±0.018 0.208±0.021 E SIDE VIEWS D NOTES: A. NO JEDEC REGISTRATION APPLIES. 0.005 B. DIMENSIONS ARE IN MILLIMETERS. C A B Ø0.260±0.02 16X 0.40 D C B 0.40 C. DIMENSIONS AND TOLERANCE PER ASME Y14.5M, 1994. D. DATUM C IS DEFINED BY THE SPHERICAL CROWNS OF THE BALLS. (Y) ±0.018 A E. PACKAGE NOMINAL HEIGHT IS 586 MICRONS ±39 MICRONS (547-625 MICRONS). F 1 2 3 4 (X) ±0.018 F. FOR DIMENSIONS D, E, X, AND Y SEE PRODUCT DATASHEET. BOTTOM VIEW G. DRAWING FILNAME: MKT-UC016AArev2. Figure 30. 16-Ball, 4x4 Array, 0.4 mm Pitch, 250 µm Ball, Wafer-Level Chip-Scale Package (WLCSP) Product-Specific Dimensions Product D E X Y FAN48630UCX 1.780 ±0.030 1.780 ±0.030 0.290 0.290 Package drawings are provided as a service to customers considering Fairchild components. Drawings may change in any manner without notice. Please note the revision and/or date on the drawing and contact a Fairchild Semiconductor representative to verify or obtain the most recent revision. Package specifications do not expand the terms of Fairchild’s worldwide terms and conditions, specifically the warranty therein, which covers Fairchild products. Always visit Fairchild Semiconductor’s online packaging area for the most recent package drawings: http://www.fairchildsemi.com/packaging/. © 2011 Fairchild Semiconductor Corporation FAN48630 • Rev. 1.0.1 www.fairchildsemi.com 14 FAN48630 — 2.5MHz, 1500mA Synchronous TinyBoost™ Regulator with Bypass Mode Physical Dimensions FAN48630 — 2.5MHz, 1500mA Synchronous TinyBoost™ Regulator with Bypass Mode © 2011 Fairchild Semiconductor Corporation FAN48630 • Rev. 1.0.1 www.fairchildsemi.com 15