FAN2564 300mA Low VIN LDO for Digital Applications Product Release Peter Khairolomour, Feb 05 2009

Two type of loads: Digital and Analog Before diving into FAN2564 product details it is important to understand that there are two major point of load categories in portable applications Digital loads application processors baseband processors memory digital TV processors GPS processors graphics processors Analog loads audio amplifiers RF amplifiers camera sensors PLL/FLL/VCO GPS receivers FAN2564 is targeted towards powering digital loads

Many digital loads in cell phones! BaseBand Processor (BB) Keyboard controller Bluetooth transceiver with baseband processor Graphics Processing Unit (GPU) Digital Base Band Processor with Main Central Processor (CPU) and Digital Signal Processor (DSP) Image Sensor Processor (ISP)

Characteristics of loads Digital Loads… Because of the inherent binary nature of digital loads, they are not as sensitive to power supply behavior such as ripple noise, thermal noise, or noise interference. They have fast dynamics as the application load can vary quickly and substantially so parameters such as power supply transient response and Iq during standby become critical They operate at low voltages because as core processor voltages go lower, power consumption is reduced. Typical range is 1.2V to 1.8V which FAN2564 will support. Analog Loads Because of the inherent sensitive nature of analog loads, noise issues that were not so much a concern for digital loads can now create problems ripple and noise feed through are typically less tolerable for sensitive analog loads analog loads typically do not share power supply inputs in order to preserve signal integrity each analog IC may have different voltage levels optimized for performance and tend to operate at a higher voltage and lower current than digital ICs.

FAN2564 Low Vin / Low Vout, 300mA LDO Features Input Voltage 1.65V to 3.6V Guaranteed 300mA Output High Initial Output Voltage Accuracy: ±1% Fixed Output Voltage options from 1.2V to 2.8V Very Low Dropout: 100mV at 300mA 45µA Quiescent Current at No Load PSRR of 60dB at 1kHz 100µs Startup Time Stable with Ceramic Capacitors as Small as 0402 Thermal and Short-Circuit Protection 4-bump WLCSP, 0.93 x 1.41 x 0.60mm 6-pin UMLP, 2.0 x 2.0 x 0.55mm Applications Digital loads. Post-regulator following standalone Buck or PMU Availability Production: NOW (1.2, 1.3, 1.5, 1.8V) Pin-to-Pin Compatible with LP3991 but with better transient response

FAN2564 Case Study This is an exercise to explore 3 different solutions to power digital loads. We will highlight tradeoffs in efficiency vs. footprint The customer’s requirements are as follows: VIN = 3.6V VOUT1 = 1.8V @ 150mA VOUT2 = 1.5V @ 150mA

Case 1: Traditional Method with Low efficiency LDO connected directly to battery is not efficient

Case 2: Traditional method with high efficiency Although efficient this solution can have large footprint and high cost

Case 3: FAN2564 Application Example FAN2564 LDO is efficient because of Low VIN

Case Study Summary Assuming 150mA delivered to the 1.8V and 1.5V Case 1: Efficiency=60%, Inductor footprint = 1x5mm^2 = 5mm^2 Case 2: Efficiency=90%, 2 Inductor footprint = 2x5mm^2 = 10mm^2 Case 3: Efficiency=83%, Inductor footprint = 1x5mm^2 =5mm^2 Conclusion: Case3 FAN2564 Low Vin LDO provides best compromise between solution footprint and efficiency

Low VIN LDO Competitive Analysis - The important parameters are to have low Iq while supporting strong load transient response. Note that Iq parameters with * have dual supply. This means that there are both bias and input currents. The importance of this is that actual standby power is higher than single input scenario because bias pin is at a higher voltage. Refer to next page. - Dropout is also critical especially because the purpose of a low VIN LDO is to bring VIN close to VOUT in order to improve efficiency. However, some devices such as On Semi, Ricoh, Micrel, and Torex have poor performing high dropout making them ineffective in applications such as VIN=1.8V  VOUT=1.5V.

Quiescent Current: Single vs Dual supply Single supply – FAN2564 Dual supply – MIC5325 IIN = 45uA PIN = 45uA*1.8V = 81mW Conclusion: Standby Power = 81mW IIN = 10uA PIN = 10uA*1.8V = 18mW IBAT = 25uA PBAT = 25uA*3.6V = 90mW Conclusion: Standby Power = 108mW IBAT = 25uA IIN = 45uA IIN = 10uA

Who are the customers/applications that you should target? Where Powering core, graphics, application, GPS, digital TV, and other digital processors in space constrained portable applications. Remember that the FAN2564 is designed to compliment the PMIC in these systems. Who Cellular: Motorola, Nokia, HTC, Pantech Curitel, Samsung, LG, SonyEricsson, RIM, Kyocera, Qualcomm, EMP MP3/PMP: Apple, iRiver, Sony, Creative Labs, Archos GPS Navigation: TomTom, Garmin, Lowrance, Magellan, Averatec Data Cards: Novatel, Option, Netgear, Kyocera, Fujitsu, Huawei, Sierra Wireless, Spreadtrum, Icera

Block Diagram and Package GND VOUT EN VIN B1 A1 B2 A2 GND VOUT EN VIN WLCSP (Bumps Facing Down) WLCSP (Bumps Facing Up) UMLP (Leads Facing Down)

Value Proposition Compared to a solution using a buck switcher, the FAN2564 reduces system footprint, cost, and EMI because it does not require an inductor. Compared to traditional LDO’s which are connected directly to VBAT, the FAN2564 provides higher efficiency because power is converted from a Low VIN. Compared to Low VIN LDO competitors, FAN2564 offers the best balance of Iq, transient response, number of pins, and package size.

Design-In support FAN2564 Datasheet http://www.fairchildsemi.com/ds/FA/FAN2564.pdf FAN2564 Product Overview http://www.fairchildsemi.com/pf/FA/FAN2564.html Evaluation Boards Request via Sales Center or Contact Product Line

Contacts Marketing contacts Application support Cell phones and data cards Peter Khairolomour peter.khairolomour@fairchildsemi.com All other customers Stephen Stella stephen.stella@fairchildsemi.com Application support George Petre george.petre@fairchildsemi.com

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