FAN5631 / FAN5632 Regulated Step-Down Charge Pump DC/DC Converter Features Description The FAN5631/FAN5632 is an advanced, thirdgeneration switched capacitor step-down DC/DC converter utilizing Fairchild's proprietary ScalarPump technology. This innovative architecture utilizes scalar switch re-configuration and fractional switching techniques to produce low output ripple, lower ESR spikes, and improve efficiency over a wide load range. 90% Peak Efficiency Low EMI Low Ripple Selectable Output Voltage:1.2V/1.5V for FAN5631 Efficiency Optimizer Feature for FAN5632 The FAN5631/FAN5632 produces a fixed regulated output voltage from an input voltage of 2.2V to 5V. Input Voltage Range: 2.2V to 5.5V Output Current: Up to 250mA To maximize efficiency, the FAN5631/5632 achieves regulation by skipping pulses. Depending on load current, the size of the switches are scaled dynamically; consequently, current spikes and EMI are minimized. An internal soft-start circuitry prevents excessive current from the supply. The device is internally protected against short-circuit and over-temperature conditions. ±5% Output Voltage Accuracy 30µA Operating Current ICC<1mA in Shutdown Mode 1.5MHz Operating Frequency Shutdown Isolates Output from Input The FAN5631 has a dual-output voltage feature. When VSEL is high, VOUT is 1.5V; and when VSEL is low, VOUT is 1.2V. Soft-Start Limits Inrush Current Short-Circuit and Over-Temperature Protection The FAN5632 has an efficiency optimizer feature that, when enabled, changes the switch mode configuration from 2:1 to 1:1 at the lower threshold of VIN. The efficiency is maintained at its peak level over a wider range of input voltages. In addition, VOUT varies from 1.2V to 1.5V as a result of this efficiency optimization. If the efficiency optimizer is not enabled, VOUT is regulated to 1.5V. Minimum External Component Count 10-Lead 3x3mm MLP Package Applications Cell Phones Handheld Computers Both the FAN5631 and FAN5632 are available in a 10lead 3x3mm MLP package. Portable Electronic Equipment Core Supply to Next-Generation Processors Low-Voltage DC Bus Digital Cameras DSP Supplies Ordering Information Part Number Package Packing Method FAN5631MPX 10-Lead 3x3mm Molded Leadless Package (MLP) Tape and Reel FAN5632MPX 10-Lead 3x3mm Molded Leadless Package (MLP) Tape and Reel All packages are lead free per JEDEC: J-STD-020B standard. © 2006 Fairchild Semiconductor Corporation FAN5631/FAN5632 Rev. 1.0.2 www.fairchildsemi.com FAN5631 / FAN5632 — Regulated Step Down Charge Pump DC/DC Converter October 2007 V SEL 1 10 EN 2 9 ON OFF C B+ GND C B- NC 3 8 NC NC 4 7 NC 5 6 C IN 10µF C OUT 10µF V IN = 2.7V to 5.5V V OUT = 1.2V to 1.5V IOUT_max= 250mA Figure 1. Typical Application FAN5631 FAN5632 with optimization FAN5631 / FAN5632 — Regulated Step Down Charge Pump DC/DC Converter Typical Application Average Efficiency (over VIN=2.7V to 5V) = 66%, with optimization = 77% Average Efficiency (over VIN=2.7V to 4.2V) = 67%, with optimization = 84% Figure 2. Typical Efficiency Graph © 2006 Fairchild Semiconductor Corporation FAN5631/FAN5632 Rev. 1.0.2 www.fairchildsemi.com 2 Top View VSEL 1 10 NC EN 2 9 VIN CB+ 3 8 NC GND 4 7 NC CB- 5 6 VOUT Figure 3. Pin Assignments Pin Definitions Pin # Name Description Output Voltage Select Logic Input Pin. The VSEL pin cannot be left floating and must be connected to either a logic high or logic low level. 1 VSEL FAN5631: If a logic low is applied to the VSEL pin, VOUT is 1.2V; if a logic high is applied, VOUT is 1.5V. FAN5632: If a logic low is applied to the VSEL pin, the efficiency optimization mode is enabled and the output voltage accuracy is relaxed to meet optimum efficiency. If a logic high is applied, the device operates like a typical charge pump converter. 2 EN Enable Input Pin. If a logic high is applied to the EN pin, the device is enabled. If a logic low is applied, the device is disabled and the supply current is reduced to less than 1µA. The EN pin cannot be left floating and must be connected to a logic high or logic low level. 3 CB+ Bucket Capacitor Positive Pin. 4 GND Ground Pin. This pin is connected to the internal MOSFET switches. This pin must be externally connected to GND. 5 CB- Bucket Capacitor Negative Pin. 6 VOUT Output Voltage Pin. 7 NC Not Connected. This pin is not internally connected. 8 NC Not Connected. This pin is not internally connected. 9 VIN Supply Voltage Input. 10 NC Not Connected. This pin is not internally connected. © 2006 Fairchild Semiconductor Corporation FAN5631/FAN5632 Rev. 1.0.2 FAN5631 / FAN5632 — Regulated Step Down Charge Pump DC/DC Converter Pin Configuration www.fairchildsemi.com 3 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 VCC ILOAD Parameter Min. Max. VIN to GND -0.3 6.0 All other pins to GND -0.3 VIN + 0.3 Load Current (1) Unit V 0.5 A 8 °C/W +260 °C ΘJC Thermal Resistance Junction-to-Tab TL Lead Temperature, Soldering 10 Seconds TJ Junction Temperature -40 +150 °C TSTG Storage Temperature -65 +150 °C Human Body Model, JESD22-A114 2.5 Charged Device Model, JESD22-C101 0.2 (2) ESD kV Notes: 1. Junction-to-ambient thermal resistance, θJA, is a strong function of PCB material, board thickness, thickness and number of copper planes, number of via used, diameter of via used, available copper surface, and attached heat sink characteristics. The estimated value for zero air flow at 0.5W is 60°C/W. 2. Using Mil Std. 883E, method 3015.7 (Human Body Model) and EIA/JESD22C101-A (Charged Device Model). 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 Parameter VCC Supply Voltage Range IOUT Output Current (VIN > 2.V) TA Min. 2.2 Operating Ambient Temperature Range © 2006 Fairchild Semiconductor Corporation FAN5631/FAN5632 Rev. 1.0.2 Typ. -40 +25 Max. Unit 5.5 V 250 mA +85 °C FAN5631 / FAN5632 — Regulated Step Down Charge Pump DC/DC Converter Absolute Maximum Ratings www.fairchildsemi.com 4 VIN = 2.2V to 5.5V, IOUT = 1mA, CIN = 10µF, COUT = 10µF, CB = 1µF, TA = -40°C to +85°C, unless otherwise noted. Typical values are at TA = 25°C. Symbol VUVLO Parameter Conditions Input Under-voltage Lockout No-load Supply Current VOUT Min. Typ. 2 No Switching Output Voltage 1.5 FAN5631, SEL to Low 1.2 FAN5632, SEL to High 1.5 FAN5632, SEL to Low Variable between 1.5 and 1.2 -5 Units V 60 FAN5631, SEL to High 1mA ≤ IOUT ≤ 150mA, VIN=2.7V to 5.5V Output Voltage Accuracy Max. µA V +5 % RLOAD Load Regulation 0mA ≤ IOUT ≤ 150mA, VIN=3.6V 0.25 RLINE Line Regulation IOUT=0.1mA 0.2 4.0 mV/V VEN=0V 0.1 1.0 µA VOUT ≤ 150mA 25 mA 90 % VIN Decreasing 2.22xVOUT V Oscillator Frequency 1.5 MHz TSD Thermal Shutdown Threshold 150 °C TSDHYS Thermal Shutdown Threshold Hysteresis 15 °C ISD ISC Shutdown Supply Current Output Short-circuit Current (3) Peak Efficiency VIN at Configuration Change FOSC VIH Enable Logic Input High Voltage VIL Enable Logic Input Low Voltage IEN Enable Logic Input Current -1 VIH VSEL Logic Input High Voltage 1.3 VIL VSEL Logic Input Low Voltage IIN VSEL Logic Input Current tON VOUT Turn-On Time mV/mA 1.3 V 0.4 V 1 µA V -1 1.6 0.4 V 1 µA FAN5631 / FAN5632 — Regulated Step Down Charge Pump DC/DC Converter Electrical Characteristic ms Note: 3. The short-circuit protection is designed to protect against pre-existing short-circuit conditions, such as assembly shorts, that exist prior to device power-up. The short-circuit current limit is 25mAAverage. Short-circuit currents in normal operation are inherently limited by the on resistance of the internal FET. Since this resistance is in the range of 1Ω, in some cases, thermal shutdown may occur. Immediately following the first thermal shutdown event, the short-circuit condition is treated as pre-existing and the load current reduces to 25mAAverage. © 2006 Fairchild Semiconductor Corporation FAN5631/FAN5632 Rev. 1.0.2 www.fairchildsemi.com 5 TA = 25°C, VOUT = 1.5V, VIN = 3.6V, CIN = 10µF, COUT = 10µF, CB = 1µF, unless otherwise noted. 90 V SE L = HIGH 85 V OU T = 1.5V I LOAD = 150m A Power Efficiency (%) Efficiency (%) 90 85 80 75 70 65 60 55 50 45 40 35 30 VIN = 3.3V 80 VSEL = HIGH 75 70 VIN = 4.2V 65 60 55 VIN = 2.7V 50 45 2 2.5 3 3.5 4 4.5 5 40 5.5 1 10 Load Current (mA) Input Voltage (V) Figure 4. Efficiency vs. Input Voltage 100 Figure 5. Efficiency vs. Load Current 1.60 ILOAD = 100mA, VSEL = LOW ILoad = 50mA Outpu t Voltage (V) 90 80 70 60 1.5 50 1.4 1.3 1.2 2.5 3 3.5 4 4.5 5 Outpu t Voltage (V) Efficiency (%) 100 1.55 TA = 25 °C 1.50 TA = 85 °C TA = -40 °C 1.45 1.40 5.5 2.5 3.0 3.5 4.0 4.5 5.0 5.5 Input Voltage (V) Input Voltage(V) Figure 6. FAN5632 Efficiency Optimizer Efficiency and Output Voltage vs. Input Voltage Figure 7. Line Regulation 0 1.54 VIN = 3.6V ILOAD = 1mA 5.5V 3.2V 2.7V Ou tpu t Voltag e (V) Load Regulation (mV/mA) 0.5 3.6V -0.5 2.2V -1 -1.5 -2 FAN5631 / FAN5632 — Regulated Step Down Charge Pump DC/DC Converter Typical Performance Characteristics 0 20 40 60 80 100 120 140 160 1.52 1.51 1.50 -50 180 Load Current (mA) -25 0 25 50 75 100 125 150 Ambient Temperature (°C) Figure 8. Load Regulation © 2006 Fairchild Semiconductor Corporation FAN5631/FAN5632 Rev. 1.0.2 1.53 Figure 9. Thermal Regulation www.fairchildsemi.com 6 TA = 25°C, VOUT = 1.5V, VIN = 3.6V, CIN = 10µF, COUT = 10µF, CB = 1µF, unless otherwise noted. ILOAD = 150mA High VEN VSEL Low Low VOUT 1.5V VOUT 75mA 1.2V 1.2V IIN 0mA (20µs/div) Figure 10. Start-Up Figure 11. Dynamic VOUT Change (FAN5631) Voltage Ripple Figure 13. Output Voltage Ripple Spectrum VIN = 3.6V ILOAD = 150mA VOUT VIN Figure 12. © 2006 Fairchild Semiconductor Corporation FAN5631/FAN5632 Rev. 1.0.2 FAN5631 / FAN5632 — Regulated Step Down Charge Pump DC/DC Converter Typical Performance Characteristics (Continued) www.fairchildsemi.com 7 V IN 0.25SW1 0.25SW1 0.5SW1 OSCILLATOR (2MHz) IN VOLTAGE REF. SOFT START Vref RAMP OUT Vref RAMP FB FB OUTPUT 150mV 0.5* INPUT 1V C+ - CONFIGURATION 0.25SW2 0.25SW2 0.5SW2 + - CONTROL LOGIC + - D R I V E R S PULSE_SKIP SHORT_CKT. 0.25SW3 0.25SW3 0.5SW3 0.25SW4 0.25SW4 0.5SW4 C- + - VOUT UVLO SHUTDOWN + THERMAL SHUTDOWN FB GND. ENABLE Figure 14. Block Diagram Detailed Description The FAN5631 / FAN5632 switched capacitor DC/DC converter automatically configures switches to achieve high efficiency and provides a regulated output voltage by means of pulse skipping, pulse frequency modulation (PFM). An internal soft-start circuit prevents excessive inrush current from the supply. Each switch is split into three segments. Based on the values of VIN, VOUT, and IOUT; an internal circuit determines the number of segments used to reduce current spikes. Pulse-skipping PFM and Fractional Switch Operation When the regulated output voltage reaches its upper limit, the switches are turned off and the output voltage reaches its lower limit. In a step-down 2:1 mode of operation, with 1.6V output as an example; when the output reaches about 1.62V (upper limit), the control logic turns off all switches: switching stops completely. This is pulse-skipping mode. Since the supply is isolated from the output, the output voltage drops. Once the output is dropped to about 1.58V (lower limit), the device returns to regular switching mode with one quarter of each switch turning on first. Another quarter of each switch is turned on if VOUT cannot reach regulation by the third charge cycle. Full switch operation occurs only during star-up or under heavyload condition, when half switch operation cannot achieve regulation within seven charge cycles. Step-Down Charge Pump Operation When VIN ≥ 2 × VOUT/9, the 2:1 configuration shown in Figure 15 is enabled. The factor 0.9 is used instead of 1 to account for the effect of resistive losses across the switches and to accommodate hysteresis in the voltage detector comparator. Two-phase, non-overlapping clock signals are generated to drive four switches. When switches 1 and 3 are on, switches 2 and 4 are off and CB is charged. When switches 2 and 4 are on, 1 and 3 are off and charge is transferred from CB to COUT. Soft-Start When VIN ≥ 2 × VOUT/9, the 1:1 configuration shown in Figure 16 is enabled. In the 1:1 configuration, switch 3 is always off and the switch 4 is always on. At 1.6V output setting, the configuration changes from 2:1 to 1:1 at VIN=3.56V. At 1.3V output setting, the change occurs at VIN=3.06V. © 2006 Fairchild Semiconductor Corporation FAN5631/FAN5632 Rev. 1.0.2 FAN5631 / FAN5632 — Regulated Step Down Charge Pump DC/DC Converter Block Diagram The soft-start feature limits inrush current when the device is initially powered up and enabled. The reference voltage is used to control the rate of the output voltage ramp-up to its final value. Typical start-up time is 1ms. Since the rate of the output voltage rampup is controlled by an internally generated slow ramp, pulse-skipping occurs and inrush current is automatically limited. www.fairchildsemi.com 8 VIN VIN S1 S1 C+ C+ S2 S2 C B VOUT VOUT C B S3 S3 C- CC C OUT OUT S4 S4 GND GND 1:1 configuration Switch 3 is always off Switch 4 is always on Switches 1 and 2 are in phase 1 Reverse position of switches 1&2 for phase 2 2:1 configuration Switches in charging phase Reverse all switches for pumping phase Figure 15. 2:1 Configuration Figure 16. Shutdown, UVLO, Short-Circuit, Current-Limit and Thermal Shutdown 1:1 Configuration Efficiency Optimizer (FAN5632) The device has an active-low shutdown pin to decrease supply current to less than 1μA. In shutdown mode, the supply is disconnected from the output. UVLO triggers when supply voltage drops below 2V. When the output voltage is lower than 150mV, a short-circuit protection is triggered. In this mode, 15 out of 16 pulses during the switching are skipped and the supply current is limited. Thermal shutdown triggers at 150ºC. © 2006 Fairchild Semiconductor Corporation FAN5631/FAN5632 Rev. 1.0.2 FAN5631 / FAN5632 — Regulated Step Down Charge Pump DC/DC Converter Switch Configuration In the FAN5632, VSEL can be tied to ground to enable the efficiency optimizer feature. To achieve an optimized efficiency, the switch mode configuration transition point is shifted from a 2:1 to a 1:1 mode until the output voltage falls to 20% of its nominal value. For example, when the nominal output voltage is 1.5V, the output voltage is allowed to drop to 1.2V. This maintains a peak efficiency of 85% for the input voltage range of 2.9V to 3.5V. For normal operation, tie VSEL high. www.fairchildsemi.com 9 bucket capacitor and therefore input and output ripple currents are also reduced. Nevertheless, due to the ESR of the input and output bypass capacitors, these current spikes generate voltage spikes at the input and output pins. These ESR spikes can be filtered because their frequencies lie at up to 12 times the clock frequencies. In applications where conductive and radiated EMI/RFI interference must be low as possible, consider additional input and output filtering. The FAN5631/FAN5632 requires one ceramic bucket capacitor in the 0.1µF to 1µF range, one 10µF output bypass capacitor, and one 10µF input bypass capacitor. To obtain optimum output ripple and noise performance, low-ESR (<0.05Ω) ceramic input and output bypass capacitors are recommended. X5R- and X7R-rated capacitors provide adequate performance over the -40°C to 85°C temperature range. The bucket capacitor’s value is dependent on load current requirements. A 1µF bucket capacitor works well in all applications at all load currents, while a 0.1µF capacitor supports most applications under 100mA of load current. The choice of bucket capacitor values should be verified in the actual application at the lowest input voltage and highest load current. A 30% margin of safety is recommended to account for the tolerance of the bucket capacitor and the variations in the onresistance of the internal switches. Layout Considerations While evaluating any switched capacitor DC-DC converter, be careful to keep the power supply source impedance low; use of long wires causing high lead inductances and resistive losses should be avoided. A carefully laid-out ground plane is essential because current spikes are generated as the bucket capacitor is charged and discharged. The input and output bypass capacitors should be placed as close to the device pins as possible. One of the key benefits of the ScalarPump architecture is that the dynamically scaled on resistance of the switches effectively reduces the peak current in the © 2006 Fairchild Semiconductor Corporation FAN5631/FAN5632 Rev. 1.0.2 FAN5631 / FAN5632 — Regulated Step Down Charge Pump DC/DC Converter Applications Information www.fairchildsemi.com 10 3.0 0.15 C 2X 6 10 A 2.25 2.20 2.00 1.55 2.00 3.10 2.33 0.78 0.55 B 3.0 0.23 0.15 C 0.02 2X D TOP VIEW 1 0.25 5 RECOMMENDED LAND PATTERN 0.8 MAX 0.10 C (0.20) 0.08 C 0.50 0.05 0.00 C SIDE VIEW SEATING PLANE (3.00±0.10) 2.25±0.05 PIN #1 IDENT (0.38) 1 5 (3.00±0.10) 1.55±0.05 0.40±0.05 10 0.30 0.20 0.5 6 0.10 0.05 2.0 FAN5631 / FAN5632 — Regulated Step Down Charge Pump DC/DC Converter Physical Dimensions C A B C BOTTOM VIEW A. CONFORMS TO JEDEC REGISTRATION MO-229, VARIATION WEED-5 B. DIMENSIONSARE IN MILLIMETERS. C. DIMENSIONSAND TOLERANCESPER ASME Y14.5M, 1994 D. LAND PATTERN DIMENSIONSARE NOMINAL REFERENCEVALUES ONLY MLP10BrevA Figure 17. © 2006 Fairchild Semiconductor Corporation FAN5631/FAN5632 Rev. 1.0.2 10-lead, Molded Leadless Package (MLP) www.fairchildsemi.com 11 ACEx® Build it Now™ CorePLUS™ CROSSVOLT™ CTL™ Current Transfer Logic™ EcoSPARK® Power247® POWEREDGE® Power-SPM™ PowerTrench® Programmable Active Droop™ QFET® QS™ QT Optoelectronics™ Quiet Series™ RapidConfigure™ SMART START™ SPM® STEALTH™ SuperFET™ SuperSOT™-3 SuperSOT™-6 Green FPS™ Green FPS™ e-Series™ GTO™ i-Lo™ IntelliMAX™ ISOPLANAR™ MegaBuck™ MICROCOUPLER™ MicroFET™ MicroPak™ MillerDrive™ Motion-SPM™ OPTOLOGIC® OPTOPLANAR® ® Fairchild® Fairchild Semiconductor® FACT Quiet Series™ FACT® FAST® FastvCore™ FPS™ FRFET® Global Power ResourceSM ® PDP-SPM™ Power220® SuperSOT™-8 SyncFET™ The Power Franchise® TinyBoost™ TinyBuck™ TinyLogic® TINYOPTO™ TinyPower™ TinyPWM™ TinyWire™ μSerDes™ UHC® UniFET™ VCX™ DISCLAIMER FAIRCHILD SEMICONDUCTOR RESERVES THE RIGHT TO MAKE CHANGES WITHOUT FURTHER NOTICE TO ANY PRODUCTS HEREIN TO IMPROVE RELIABILITY, FUNCTION, OR DESIGN. FAIRCHILD DOES NOT ASSUME ANY LIABILITY ARISING OUT OF THE APPLICATION OR USE OF ANY PRODUCT OR CIRCUIT DESCRIBED HEREIN; NEITHER DOES IT CONVEY ANY LICENSE UNDER ITS PATENT RIGHTS, NOR THE RIGHTS OF OTHERS. THESE SPECIFICATIONS DO NOT EXPAND THE TERMS OF FAIRCHILD’S WORLDWIDE TERMS AND CONDITIONS, SPECIFICALLY THE WARRANTY THEREIN, WHICH COVERS THESE PRODUCTS. LIFE SUPPORT POLICY FAIRCHILD’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF FAIRCHILD SEMICONDUCTOR CORPORATION. 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. 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. FAN5631 / FAN5632 — Regulated Step Down Charge Pump DC/DC Converter TRADEMARKS The following are registered and unregistered trademarks and service marks Fairchild Semiconductor owns or is authorized to use and is not intended to be an exhaustive list of all such trademarks. PRODUCT STATUS DEFINITIONS Definition of Terms Datasheet Identification Product Status Definition Advance Information Formative or In Design This datasheet contains the design specifications for product development. Specifications may change in any manner without notice. Preliminary First Production This datasheet contains preliminary data; supplementary data will be published at a later date. Fairchild Semiconductor reserves the right to make changes at any time without notice to improve design. No Identification Needed Full Production This datasheet contains final specifications. Fairchild Semiconductor reserves the right to make changes at any time without notice to improve design. Obsolete Not In Production This datasheet contains specifications on a product that has been discontinued by Fairchild Semiconductor. The datasheet is printed for reference information only. Rev. I31 © 2006 Fairchild Semiconductor Corporation FAN5631/FAN5632 Rev. 1.0.2 www.fairchildsemi.com 12 FAN5631 / FAN5632 — Regulated Step Down Charge Pump DC/DC Converter © 2006 Fairchild Semiconductor Corporation FAN5631/FAN5632 Rev. 1.0.2 www.fairchildsemi.com 13