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| www.fairchildsemi.com FAN2534/FAN2535 150 mA CMOS LDO Regulator with Fast Start, Enable Features * * * * * * * * * * * 70dB Ripple rejection ( >45dB up to 1MHz) 150sec Power On Time 150sec Enable Time Low noise - 50Vrms Enable optimized for CDMA time slices 180 mV dropout voltage at 150 mA Enable/Shutdown Control Enable time independent of noise bypass capacitor value SOT23-5 package Thermal limiting 300 mA trimmed current limit low dropout voltage, fast enable required in CDMA handset applications, exceptional loop stability to accommodate a wide variety of external capacitors, and a compact SOT23-5 surface-mount package. These products offer significant improvements over older Bipolar and CMOS designs and are pin-compatible with many popular devices. The FAN2534 and FAN2535 devices are distinguished by the assignment of pin 4: FAN2534: pin 4 - ADJ, allowing the user to adjust the output voltage over a wide range using an external voltage divider. FAN2534-XX: pin 4 - BYP, to which a bypass capacitor may be connected for optimal noise performance. Output voltage is fixed, as specified by the suffix XX. FAN2535-XX: pin 4 - ERR, a flag which indicates that the output voltage has dropped below the specified minimum due to a fault condition. The standard fixed output voltages available are 2.6V, 2.85V, and 3.0V . Custom output voltages are also available: please contact your local Fairchild Sales Office for information. Applications * * * * Cellular Phones and accessories PDAs Portable cameras and video recorders Laptop, notebook and palmtop computers Description The FAN2534/FAN2535 family of micropower low-dropout voltage regulators utilize CMOS technology to offer a new level of cost-effective performance in GSM, TDMA, and CDMA cellular handsets, laptop and notebook computers, and other portable devices. Proprietary design technics ensure high ripple rejection. Other features include low noise, short circuit current limit, thermal shutdown circuit, Block Diagrams EN VIN Bandgap Error Amplifier p VOUT ADJ Thermal Sense FAN2534 GND FAN2534-XX Thermal Sense Thermal Sense FAN2535-XX VIN BYP Bandgap Error Amplifier p VOUT EN VIN Bandgap p VOUT EN ERR Error Amplifier GND GND REV. 1.0.2 8/26/03 FAN2534/FAN2535 PRODUCT SPECIFICATION Pin Assignments 1 FB VIN 5 VOUT SHDN GND 2 CAP+ EN 3 CAP- 4 ADJ/BYP/ERR Pin No. 1. 2. 3. 4. 5. FAN2534 VIN GND EN ADJ VOUT FAN2534-XX VIN GND EN BYP VOUT FAN2535-XX VIN GND EN ERR VOUT Pin Descriptions Pin Name ADJ BYP ERR EN VIN VOUT GND Pin No. 4 4 4 3 1 5 2 Type Input Passive Open drain Digital Input Power in Power out Power Pin Function Description FAN2534 Adjust. Ratio of potential divider from VOUT to ADJ determines output voltage. FAN2534-XX Bypass. Connect 10 nF capacitor for noise reduction. FAN2535-XX Error. Error flag output. LOW when Vout< 95% of nominal; HIGH when Vout> 95% of nominal. Enable. LOW in Shutdown Mode; HIGH in Enable Mode Voltage Input. Supply voltage input. Voltage Output. Regulated output voltage. Ground. Absolute Maximum Ratings (Note 1) Parameter Power Supply Voltages VIN (Measured to GND); Enable Input (EN); ERR Output; Power Dissipation Operating Junction Temperature Lead Soldering (5 seconds) Storage Electrostatic Discharge (Note 2) -65 4 -65 0 7 Internally limited 150 260 150 C C C kV V Min. Typ. Max. Unit 2 REV. 1.0.2 8/26/03 PRODUCT SPECIFICATION FAN2534/FAN2535 Operating Conditions Symbol VIN VOUT VOUT VEN VERR TJ JA JC Input Voltage Range Output Voltage Range FAN2534-XX, FAN2535-XX (Note 3) Output Voltage Range (FAN2534 only) Enable Input Voltage ERR Flag Voltage Junction Temperature Thermal resistance Thermal resistance -40 220 130 Parameter Min. VOUT+VDO 2.3 2.0 0 Typ. Max. 6.5 3.3 5.0 VIN VIN +125 Units V V V V V C C/W C/W DC Electrical Characteristics (Notes 4, 5) Symbol Regulator VDO Drop Out Voltage (Note 6) IOUT = 100 A IOUT = 50 mA IOUT = 100 mA IOUT = 150 mA 2.5 50 100 180 -1 -3.7 90 110 300 EN = 0V 155 15 FAN2535 only 90 93 0.4 1.4 2 1 1 96 1.2 4 75 140 220 1 2 mV mV mV mV % % A A Parameter Conditions Min. Typ. Max. Units VO Output Voltage Accuracy (Note 7) Initial Accuracy at no load Over Line, Load & Temp IGND(NL) Ground Pin Current IGND(FL) Ground Pin Current Current Limit IGSD TSH Shut-Down Current Thermal Shutdown Temperature Hysteresis ERR Trip Level Logic Low Voltage Logic High Voltage Input Current High Input Current Low Protection No Load IOUT = 150 mA 400 1 mA A C C % V V A A ETL VEL VEH IEH IEL Enable Input REV. 1.0.2 8/26/03 3 FAN2534/FAN2535 PRODUCT SPECIFICATION Switching Characteristics (Notes 4, 5) Parameter Conditions Min. Typ. Max. Unit Enable Response time (Note 8) Power "ON" Response time Error Flag Response time (FAN2535-XX only) CL=10F CBP=10nF CL=10uF CBP=10nF VOUT = 3.0V 150 150 300 500 3 sec sec msec AC Performance Characteristics (Notes 4, 5) Symbol Parameter Conditions Min. Typ. Max. Units VOUT/ VIN VOUT/ VOUT eN Line regulation Load regulation Output noise VIN = (VOUT + 1) to 6.5V, IL = 10mA IOUT = 0.1 to 100mA BW: 300Hz-50KHz COUT = 10F, CBYP = 0.01F 100 Hz, COUT = 1F, CBYP = 0.01F 0mA 0.2 2.0 % /V % VRMS PSRR Power Supply Ripple Rejection 70 dB Notes: 1. Functional operation under any of these conditions is NOT implied. Performance and reliability are guaranteed only if Operating Conditions are not exceeded. 2. Using Mil Std. 883E, method 3015.7(Human Body Model), 400V when using JEDEC method A115-A (Machine Model). 3. For specific output voltages of the fixed oputput voltage versions please refer to the table: "Output Voltage Options and Ordering Information" on Page 9. Custom fixed output voltages, not listed in the table, are also available. 4. Unless otherwise stated, TA = 25C, VIN = VOUT + 1V, IOUT = 100A, VEH > 2.0 V. 5. Bold values indicate -40 4 REV. 1.0.2 8/26/03 PRODUCT SPECIFICATION FAN2534/FAN2535 Functional Description Utilizing CMOS technology, the FAN2534/FAN2535 product family is optimized for use in compact battery powered systems, offering a unique combination of high ripple rejection, low noise, low power consumption, extremely low dropout voltages, high tolerance for a variety of output capacitors, and less than 1A "OFF" current. In the circuit, a differential amplifier controls a series-pass P-Channel MOSFET, and a separate error amplifier compares the load voltage at the output with an onboard trimmed low voltage bandgap reference. The series resistance of the pass P-Channel MOSFET is approximately 1 Ohm, yielding an unusually low dropout voltage even under high load conditions. Thermal shutdown and current limit circuits protect the device under extreme conditions. When the device temperature reaches 155C, the output is disabled, until the device cooles down by 15C, then re-enabled. The user can to shut down the device using the Enable control pin at any time. The current limit circuit is trimmed, which leads to consistent power on /enable delays, and provides safe short circuit current densities even in narrow traces of the PCB. A carefully optimized control loop accommodates a wide range of ESR values in the output bypass capacitor, allowing the user to optimize space, cost, and performance requirements. An Enable pin shuts down the regulator output to conserve power, reducing supply current to less than 1A. The output can then be re-Enabled within 150Sec, fulfilling the fast power-cycling needs of CDMA applications. Depending on the device type selected, other control and status functions are available at pin 4. The fixed-voltage versions are available with either a noise-bypass pin or an Error flag pin option. The error flag can be used as a diagnostic function to indicate that the output voltage has dropped more than 5% below the nominal value. The adjustable-voltage versions utilize pin 4 to connect to an external voltage divider which feeds back to the regulator error amplifier, thus setting the output voltage to the desired value. Applications Information External Capacitors - Selection The FAN2534/FAN2535 allows the user to utilize a wide variety of capacitors compared to other LDO products. An innovative design approach offers significantly reduced sensitivity to ESR (Equivalent Series Resistance), which degrades regulator loop stability in older designs. While the improvements featured in the FAN2534/FAN2535 family greatly simplify the design task, capacitor quality still must be considered if the designer is to achieve optimal circuit performance. In general, ceramic capacitors offer superior ESR performance, and a smaller case size than tantalums. Input Capacitor An input capacitor of 2.2F (nominal value) or greater, connected between the Input pin and Ground, placed in close proximity to the device, will improve transient response and ripple rejection. Higher values will further improve ripple rejection and transient response. An input capacitor is recommended when the input source, either a battery or a regulated AC voltage, is located far from the device. Any good quality ceramic, tantalum, or metal film capacitor will give acceptable performance, however in extreme cases capacitor surge current ratings may have to be considered. Output Capacitor An output capacitor is required to maintain regulator loop stability. Stable operation will be achieved with a wide variety of capacitors with ESR values ranging from 0m up to 400m. Multilayer ceramic, tantalum or aluminum electrolytic capacitors may be used. A nominal value of at least 1F is recommended. Note that the choice of output capacitor effects load transient response, ripple rejection, and it has a slight effect on noise performance as well. Bypass Capacitor (FAN2534-XX Only) In the fixed-voltage configuration, connecting a capacitor between the bypass pin and ground can significantly reduce output noise. Values ranging from 0pF to 47nF can be used, depending on the sensitivity to output noise in the application. At the high-impedance Bypass pin, care must be taken in the PCB layout to minimize noise pickup, and capacitors must be selected to minimize current loading (leakage). Noise pickup from external sources can be considerable. Leakage currents into the Bypass pin will directly affect regulator accuracy and should be kept as low as possible; thus, highquality ceramic and film types are recommended for their low leakage characteristics. Cost-sensitive applications not concerned with noise can omit this capacitor. REV. 1.0.2 8/26/03 5 FAN2534/FAN2535 PRODUCT SPECIFICATION Control Functions Enable Pin Connecting 2.0V or greater to the Enable pin will enable the output, while 0.4V or less will disable it while reducing the quiescent current consumption to less than 1A. If this shutdown function is not needed, the pin can simply be connected permanently to the VIN pin. Allowing this pin to float will cause erratic operation. Error Flag (FAN2535-XX Only) Fault conditions such as input voltage dropout (low VIN), overheating, or overloading (excessive output current), will set an error flag: The ERR pin which is an open-drain output, will go LOW when VOUT is less than 95% or the specified output voltage. When the voltage at VOUT is greater than 95% of the specified output voltage, the ERR pin is HIGH. A logic pullup resistor of 100K Ohm is recommended at this output. The pin can be left disconnected if unused. Thermal Protection The FAN2534/FAN2535 is designed to supply high peak output currents for brief periods, however sustained excessive output load at high input - output voltage difference will cause the device temperature to increase and exceed maximum ratings due to power dissipation. During output overload conditions, when the die temperature exceeds the shutdown limit temperature of 155C, an onboard thermal protection will disable the output until the temperature drops approximately 15C below the limit, at which point the output is re-enabled. During a thermal shutdown situation the user may assert the power-down function at the Enable pin, reducing power consumption to a minimum. The relationship describing the thermal behavior of the package is: T J ( max ) - T A P D ( max ) = ------------------------------- JA where TJ(max) is the maximum allowable junction temperature of the die, which is 125C, and TA is the ambient operating temperature. JA is dependent on the surrounding PC board layout and can be empirically obtained. While the JC (junction-to-case) of the SOT23-5 package is specified at 130C /W, the JA of the minimum PWB footprint will be at least 235C /W. This can be improved upon by providing a heat sink of surrounding copper ground on the PWB. Depending on the size of the copper area, the resulting JA can range from approximately 180C /W for one square inch to nearly 130C /W for 4 square inches. The addition of backside copper with through-holes, stiffeners, and other enhancements can also aid in reducing thermal resistance. The heat contributed by the dissipation of other devices located nearby must be included in the design considerations. Once the limiting parameters in these two relationships have been determined, the design can be modified to ensure that the device remains within specified operating conditions. If overload conditions are not considered, it is possible for the device to enter a thermal cycling loop, in which the circuit enters a shutdown condition, cools, reenables, and then again overheats and shuts down repeatedly due to an unmanaged fault condition. Adjustable Version The FAN2534 adjustable version includes an input pin ADJ which allows the user to select an output voltage ranging from 2.5V to near VIN, using an external resistor divider. The voltage VADJ presented to the ADJ pin is fed to the onboard error amplifier which adjusts the output voltage until VADJ is equal to the onboard bandgap reference voltage of 1.00V(typ). The equation is: R upper V OUT = 1.00V x 1 + --------------R lower Thermal Characteristics The FAN2534/FAN2535 is designed to supply 150mA at the specified output voltage with an operating die (junction) temperature of up to 125C. Once the power dissipation and thermal resistance is known, the maximum junction temperature of the device can be calculated. While the power dissipation is calculated from known electrical parameters, the actual thermal resistance depends on the thermal characteristics of the SOT23-5 surface-mount package and the surrounding PC Board copper to which it is mounted. The power dissipation is equal to the product of the input-tooutput voltage differential and the output current plus the ground current multiplied by the input voltage, or: P D = ( V IN - V OUT )I OUT + V IN I GND Since the bandgap reference voltage is trimmed, 1% initial accuracy can be achieved. The total value of the resistor chain should not exceed 250K Ohm total to keep the error amplifier biased during no-load conditions. Programming output voltages very near VIN need to allow for the magnitude and variation of the dropout voltage VDO over load, supply, and temperature variations. Note that the low-leakage FET input to the CMOS Error Amplifier induces no bias current error to the calculation. The ground pin current IGND can be found in the charts provided in the Electrical Characteristics section. 6 REV. 1.0.2 8/26/03 PRODUCT SPECIFICATION FAN2534/FAN2535 General PWB Layout Considerations For optimum device performance, careful circuit layout and grounding technics must be used. Establishing a small local ground, to which the GND pin, and the output and bypass capacitors are connected, is recommended, while the input capacitor should be grounded to the main ground plane. The quiet local ground is then routed back to the main ground plane using feedthrough vias. In general, the highfrequency compensation components (input, bypass, and output capacitors) should be located as close to the device as possible. The proximity of the output capacitor is especially important to achieve optimum performance, especially during high load conditions. A large copper area in the local ground serves as heat sink (as discussed above) when high power dissipation significantly increases device temperature. Component-side copper provides significantly better thermal performance. Added feedthrough connecting the device side ground plane to the back plane further reduces thermal resistance. REV. 1.0.2 8/26/03 7 FAN2534/FAN2535 PRODUCT SPECIFICATION Typical Performance Characteristics Enable Delay VEN VEN C out = 3.3F, C byp = 10nF, I load = 150mA Enable Delay = 152Sec C out = 3.3F, C byp = 10nF, I load = 150mA Disable Delay = 214Sec Disable Delay VOUT VOUT Power on Delay 110 VIN Power on Delay = 150Sec Ground Current vs Ambient Temperature ILOAD = 0mA Ground Current (A) C out = 3.3F, C byp = 10nF, ILOAD = 150mA 100 90 VOUT 80 70 -40 -20 0 20 40 60 80 100 120 Ambient Temperature (C) Noise Plot -30 dB -35 -40 Cout = 3.3F, Cbyp = 10nF Iload = 150mA Ripple Rejection Plot 1.8V 1.6V 1.4V 1.2V 1V 800nV 600nV 400nV Cout = 3.3F, Cbyp = 10nF Iload = 150mA -45 -50 -55 -60 -65 -70 -75 200nV -80 8 REV. 1.0.2 8/26/03 PRODUCT SPECIFICATION FAN2534/FAN2535 Typical Performance Characteristics (Continued) VOUT Variation vs Ambient Temperature 0.6 Droupout Voltage (mV) 0.4 VOUT Variation (%) 0.2 Iload = 150mA 0.0 -0.2 -0.4 -0.6 -0.8 -25 0 25 50 Ambient Temperature (C) 75 240 220 Iload = 150mA 200 180 160 140 120 -40 Dropout Voltage vs Ambient Temperature -20 0 20 40 Ambient Temperature (C) 60 Dropout Voltage vs Load Current 160 140 Droupout Voltage (mV) 120 100 80 60 40 20 0 0 25 50 75 100 Load Current (mA) 125 150 T = 25C REV. 1.0.2 8/26/03 9 FAN2534/FAN2535 PRODUCT SPECIFICATION Mechanical Dimensions 5-Lead SOT-23 Package B e c Symbol A A1 E H Inches Min .035 .000 .008 .003 .106 .059 Max .057 .006 .020 .010 .122 .071 Millimeters Min .90 .00 .20 .08 2.70 1.50 Max 1.45 .15 .50 .25 3.10 1.80 Notes L B c D E e e1 e1 D .037 BSC .075 BSC .087 .004 0 .126 .024 10 .95 BSC 1.90 BSC 2.20 .10 0 3.20 .60 10 A A1 H L 10 REV. 1.0.2 8/26/03 PRODUCT SPECIFICATION FAN2534/FAN2535 Output Voltage Options and Ordering Information Product Number FAN2534SX FAN2534S26X FAN2534S30X FAN2535S26X FAN2535S285X VOUT Adj. 2.6 3.0 2.6 2.85 Pin 4 Function Adjust Bypass Bypass Error output Error output Package Marking AJA AJG AJW AKG AKN Tape and Reel Information Quantity 3000 Reel Size 7" Width 8mm 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. 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 THE PRESIDENT 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. www.fairchildsemi.com 8/26/03 0.0m 004 Stock#DS30002591 2002 Fairchild Semiconductor Corporation |
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