www.fairchildsemi.com FAN2508, FAN2509 50 mA CMOS LDO Regulators Features • • • • • • • wide variety of external capacitors, and the compact SOT23-5 surface-mount package. The FAN2508/09 family of products offer significant improvements over older BiCMOS designs and are pin-compatible with many popular devices. The output is thermally protected against overload. Ultra Low Power Consumption 50 mV dropout voltage at 50 mA 25 µA ground current at 50 mA Enable/Shutdown Control SOT23-5 package Thermal limiting 300 mA peak current The FAN2508 and FAN2509 devices are distinguished by the assignment of pin 4: FAN2508: pin 4 – ADJ, allowing the user to adjust the output voltage over a wide range using an external voltage divider. Applications • • • • Cellular Phones and accessories PDAs Portable cameras and video recorders Laptop, notebook and palmtop computers FAN2508-XX: pin 4 – BYP, to which a bypass capacitor may be connected for optimal noise performance. Output voltage is fixed, indicated by the suffix XX. Description The FAN2508/09 family of micropower low-dropout voltage regulators utilize CMOS technology to offer a new level of cost-effective performance in GSM and TDMA cellular handsets, Laptop and Notebook portable computers, and other portable devices. Features include extremely low power consumption and low shutdown current, low dropout voltage, exceptional loop stability able to accommodate a FAN2509-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 2.5V, 2.6V, 2.7V, 2.8V, 2.85V, 3.0V, and 3.3V. Custom output voltage are also available: please contact your local Fairchild Sales Office for information. Block Diagrams EN EN VIN VIN Bandgap Error Amplifier BYP Bandgap p VOUT Error Amplifier p VOUT ADJ Thermal Sense Thermal Sense GND FAN2508 GND FAN2508-XX EN VIN ERR Bandgap Error Amplifier p VOUT Thermal Sense GND FAN2509-XX REV. 1.0.6 2/14/03 PRODUCT SPECIFICATION FAN2508/FAN2509 Pin Assignments VIN 1 GND 2 EN 3 5 VOUT 4 ADJ/BYP/ERR Pin No. FAN2508 FAN2508-XX FAN2509-XX 1. VIN VIN VIN 2. GND GND GND 3. EN EN EN 4. ADJ BYP ERR 5. VOUT VOUT VOUT Pin Descriptions Pin Name Pin No. Type Pin Function Description ADJ 4 Input FAN2508 Adjust. Ratio of potential divider from VOUT to ADJ determines output voltage. BYP 4 Passive FAN2508-XX Bypass. Connect 470 pF capacitor for noise reduction. ERR 4 Open drain FAN2509-XX Error. Error flag output. 0: Output voltage < 95% of nominal. 1: Output voltage > 95% of nominal. EN 3 Digital Input Enable. 0: Shutdown VOUT. 1: Enable VOUT. VIN 1 Power in Voltage Input. Supply voltage input. VOUT 5 Power out Voltage Output. Regulated output voltage. GND 2 Power Ground. Functional Description Designed utilizing CMOS process technology, the FAN2508/09 family of products are carefully optimized for use in compact battery-powered devices, offering a unique combination of low power consumption, extremely low dropout voltages, high tolerance for a variety of output capacitors, and the ability to disable the output to less than 1µA under user control. In the circuit, a difference amplifier controls the current through a series-pass P-Channel MOSFET, comparing the load voltage at the output with an onboard low-drift bandgap reference. The series resistance of the pass P-Channel MOSFET is approximately 1Ω, resulting in an unusually low dropout voltage under load when compared to older bipolar pass-transistor designs. 2 Protection circuitry is provided onboard for overload conditions. In conditions where the device reaches temperatures exceeding the specified maximums, an onboard circuit shuts down the output, where it remains suspended until it has cooled before re-enabling. The user is also free to shut down the device using the Enable control pin at any time. Careful design of the output regulator amplifier assures loop stability over a wide range of ESR values in the external output capacitor. A wide range of values and types can be accomodated, allowing the user to select a capacitor meeting his space, cost, and performance requirements, and enjoy reliable operation over temperature, load, and tolerance variations. REV. 1.0.6 2/14/03 FAN2508/FAN2509 Depending on the model selected, a number of control and status functions are available to enhance the operation of the LDO regulator. An Enable pin, available on all devices, allows the user to shut down the regulator output to conserve power, reducing supply current to less than 1µA. The adjustable-voltage versions of the device utilize pin 4 to connect to an external voltage divider which feeds back to the regulator error amplifier, thereby setting the voltage as desired. Two other functions are available at pin 4 in the fixed-voltage versions: in noise-sensitive applications, an external Bypass capacitor connection is provided that allows the user to achieve optimal noise performance at the output, while the Error output functions as a diagnostic flag to indicate that the output voltage has dropped more than 5% below the nominal fixed voltage. PRODUCT SPECIFICATION Bypass Capacitor (FAN2508 Only) In the fixed-voltage configuration, connecting a capacitor between the bypass pin and ground can significantly reduce noise on the output. Values ranging from 470pF to 10nF 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 circuit 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. Applications Information Control Functions External Capacitors – Selection The FAN2508/09 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 (Effective Series Resistance), which degrades regulator loop stability in older designs. While the improvements featured in the FAN2508/09 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, at a lower cost and a smaller case size than tantalums. Those with X7R or Y5Vdielectric offer the best temperature coefficient characteristics. The combination of tolerance and variation over temperature in some capacitor types can result in significant variations, resulting in unstable performance over rated conditions. Input Capacitor An input capacitor of 2.2µF (nominal value) or greater, connected between the Input pin and Ground, located in close proximity to the device, will improve transient response and noise rejection. Higher values will offer superior input 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 tantalum capacitors with a surge current rating appropriate to the application must be selected to avoid catastrophic failure. Output Capacitor An output capacitor is required to maintain regulator loop stability. Unlike many other LDO regulators, the FAN2508/09 family of products are nearly insensitve to output capacitor ESR. Stable operation will be achieved with a wide variety of capacitors with ESR values ranging from 10mΩ to 10Ω or more. Tantalum or aluminum electrolytic, or multilayer ceramic types can all be used. A nominal value of at least 1µF is recommended. REV. 1.0.6 2/14/03 Enable Pin Applying a voltage of 0.4V or less at the Enable pin will disable the output, reducing the quiescent output current to less than 1µA, while a voltage of 2.0V or greater will enable the device. If this shutdown function is not needed, the pin can simply be connected to the VIN pin. Allowing this pin to float will cause erratic operation. Error Flag (FAN2509 only) To indicate conditions such as input voltage dropout (low VIN), overheating, or overloading (excessive output current), the ERR pin indicates a fault condition. It is an opendrain output which is HIGH when the voltage at VOUT is greater than 95% of the nominal rated output voltage and LOW when VOUT is less than 95% or the rated output voltage, as specified in the error trip level characteristics. A logic pullup resistor of 100KΩ is recommended at this output. The pin can be left disconnected if unused. Thermal Protection The FAN2508/09 is designed to supply high peak output currents of up to 1A for brief periods, however this output load 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 150°C, onboard thermal protection will disable the output until the temperature drops below this limit, at which point the output is then re-enabled. During a thermal shutdown situation the user may assert the power-down function at the Enable pin, reducing power consumption to the minimum level IGND · VIN. 3 PRODUCT SPECIFICATION Thermal Characteristics The FAN2508/09 is designed to supply 50mA at the specified output voltage with an operating die (junction) temperature of up to 125°C. 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 thermal resistance is a result of the thermal characteristics of the compact 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 The ground pin current IGND can be found in the charts provided in the Electrical Characteristics section. The relationship describing the thermal behavior of the package is: T J ( max ) – T A P D ( max ) = ------------------------------- θ JA where TJ(max) is the maximum allowable junction temperature of the die, which is 125°C, and TA is the ambient operating temperature. θJA is dependent on the surrounding PC board layout and can be empirically obtained. While the θJC (junction-to-case) of the SOT23-5 package is specified at 130°C /W, the θJA of the minimum PWB footprint will be at least 235°C /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 θJA can range from approximately 180°C /W for one square inch to nearly 130°C /W for 4 square inches. The addition of backside copper with through-holes, stiffeners, and other enhancements can also aid in reducing this value. The heat contributed by the dissipation of other devices located nearby must be included in 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 4 FAN2508/FAN2509 the device to enter a thermal cycling loop, in which the circuit enters a shutdown condition, cools, re-enables, and then again overheats and shuts down repeatedly due to an unmanaged fault condition. Operation of Adjustable Version The adjustable version of the FAN2508/09 includes an input pin ADJ which allows the user to select an output voltage ranging from 1.8V 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 1.32V(typ). The equation is: R upper V OUT = 1.32V × 1 + ---------------R lower The total value of the resistor chain should not exceed 250KΩ 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. General PWB Layout Considerations To achieve the full performance of the device, careful circuit layout and grounding technique must be observed. Establishing a small local ground, to which the GND pin, 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 optimal noise compensation from the onboard error amplifier, especially during high load conditions. A large copper area in the local ground will provide the heat sinking discussed above when high power dissipation significantly increases the temperature of the device. Component-side copper provides significantly better thermal performance for this surface-mount device, compared to that obtained when using only copper planes on the underside. REV. 1.0.6 2/14/03 FAN2508/FAN2509 PRODUCT SPECIFICATION Absolute Maximum Ratings (beyond which the device may be damaged)1 Parameter Min Typ Max Unit 0 7 V 0 7 V 0 7 V Power Supply Voltages VIN (Measured to GND) Enable Input (EN) Applied voltage (Measured to GND)2 ERR Output Applied voltage (Measured to GND)2 Power Dissipation3 Internally limited Temperature Junction -65 Lead Soldering (5 seconds) Storage -65 4 Electrostatic Discharge 150 °C 260 °C 150 °C 4 kV 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. Applied voltage must be current limited to specified range. 3. Based upon thermally limited junction temperature: T J ( max ) – T A P D = ------------------------------Θ JA 4. Human Body Model is 4kV minimum using Mil Std. 883E, method 3015.7. Machine Model is 400V minimum using JEDEC method A115-A. Recommended Operating Conditions Parameter VIN Min Input Voltage Range VOUT Output Voltage Range, Adjustable VEN Enable Input Voltage VERR ERR Flag Voltage Nom Max Units 2.7 6.5 V VREF VIN-VDO V 0 VIN V VIN V +125 °C TJ Junction Temperature θJA Thermal resistance 220 °C/W θJC Thermal resistance 130 °C/W REV. 1.0.6 2/14/03 -40 5 PRODUCT SPECIFICATION FAN2508/FAN2509 Electrical Characteristics (Notes 1, 2) Symbol Parameter Conditions Min. Typ. Max. Units IOUT = 100 µA 2.5 4 mV IOUT = 50 mA 50 75 mV 2 % 1.32 1.40 V 6 % 50 µA 1 µA Regulator VDO Drop Out Voltage ∆VO Output Voltage Accuracy VDO Reference Voltage Accuracy, Adjustable Mode ∆VO3 Output Voltage Accuracy, Adjustable Mode IGND Ground Pin Current -2 1.24 -6 IOUT = 50 mA Protection Current Limit Thermally Protected IGSD Shut-Down Current TSH Thermal Protection Shutdown Temperature ETL ERR Trip Level EN = 0V 150 FAN2509 only 90 °C 95 99 % 1.2 0.4 V Enable Input VIL Logic Low Voltage VIH Logic High Voltage IIH Input Current High 1 µA II Input Current Low 1 µA 2.0 1.4 V Switching Characteristics (Notes 1, 2) Parameter Conditions Min. Typ. Max. Unit 500 µsec 3 msec Enable Input Response time Error Flag (FAN2509-XX) Response time Performance Characteristics (Notes 1, 2) Symbol Parameter Conditions ∆VOUT/∆VIN Line regulation VIN = (VOUT + 1) to 6.5V 0.3 ∆VOUT/VOUT Load regulation IOUT = 0.1 to 50mA 1.0 eN Output noise 10Hz–1KHz COUT = 10µF, CBYP = 0.01µF <7 >10KHz, COUT = 10µF, CBYP = 0.01µF <0.01 120 Hz, COUT = 10µF, CBYP = 0.01µF 43 PSRR Power Supply Rejection Min. Typ. Max. Units % /V 2.0 % µV/ Hz dB Notes: 1. Unless otherwise stated, TA = 25°C, VIN = VOUT + 1V, IOUT = 100µA, VIH > 2.0 V. 2. Bold values indicate -40 ≤ TJ ≤ 125°C. 3. The adjustable version, has a bandgap voltage range of 1.24V to 1.40V with a nominal value of 1.32V. 4. When using repeated cycling. 6 REV. 1.0.6 2/14/03 FAN2508/FAN2509 PRODUCT SPECIFICATION Typical Performance Characteristics Power Supply Rejection Ratio Power Supply Rejection Ratio 100 40 60 40 VIN = 4.0V VOUT = 3.0V 100 20 Power Supply Rejection Ratio Power Supply Rejection Ratio 40 IOUT = 100µA COUT = 10µF Cer. IOUT = 10mA COUT = 10µF Cer. 40 VIN = 4.0V VOUT = 3.0V 60 40 20 0 10 100 1k 10k 100k 1M 10M Frequency (Hz) 0 10 1k 10k 100k 1M 10M Frequency (Hz) 100 1k 10k 100k 1M 10M Frequency (Hz) Noise Performance Power Supply Rejection Ratio vs. Voltage Drop 10 70 40 30 COUT = 1.0µF Cer. 50mA 20 50 40 10mA 30 20 3.0 3.6 0 4.1 3.0 Ground Pin Current 19.00 17.00 15.00 0.1 10 1 Load Current (mA) REV. 1.0.6 2/14/03 0.0001 10 4.1 100 35.00 35.00 30.00 30.00 25.00 20.00 15.00 10.00 5.00 0.00 3.0 VOUT = 3V IOUT = 100µA 4.0 5.0 6.0 Input Voltage (V) 1k 10k 100k Frequency (Hz) 1M Ground Pin Current Ground Pin Current Quiescent Current (µA) 21.00 3.6 COUT = 1.0µF CBYP = 0.01µF I L = 10µA Voltage (V) 25.00 VIN = 4V VOUT = 3V 0.01 COUT = 10µF Cer. 50mA Voltage (V) 23.00 0.1 0.001 10 10 VIN = 4.0V VOUT = 3.0V 1 IOUT = 100µA Quiescent Current (µA) 50 60 10mA IOUT = 100µA PSRR (dB) 60 Noise (µV/ Hz) 70 PSRR (dB) 60 IOUT = 50mA 80 COUT = 10µF Cer. 20 Power Supply Rejection Ratio vs. Voltage Drop Quiescent Current (µA) Power Supply Rejection Ratio PSRR (dB) 60 1k 10k 100k 1M 10M Frequency (Hz) 100 VIN = 4.0V 80 VOUT = 3.0V PSRR (dB) PSRR (dB) VIN = 4.0V 80 VOUT = 3.0V 0 10 100 40 0 10 100 1k 10k 100k 1M 10M Frequency (Hz) 100 20 60 20 0 10 100 1k 10k 100k 1M 10M Frequency (Hz) 100 0 VIN = 4.0V IOUT = 50mA 80 VOUT = 3.0V COUT = 1.0µF Cer. PSRR (dB) 60 20 100 VIN = 4.0V IOUT = 10mA 80 VOUT = 3.0V COUT = 1.0µF Cer. PSRR (dB) PSRR (dB) IOUT = 100µA 80 COUT = 1.0µF Cer. 0 10 Power Supply Rejection Ratio 100 7.0 25.00 20.00 15.00 10.00 VOUT = 3V IOUT = 50mA 5.00 0.00 3.0 4.0 5.0 6.0 7.0 Input Voltage (V) 7 PRODUCT SPECIFICATION FAN2508/FAN2509 Typical Performance Characteristics (continued) 75 25 0 -40 0 40 80 Temperature (°C) 50 50.00 VIN = 4V VOUT = 3V IL = 50mA 25 0 -40 125 Dropout Voltage (mV) VIN = 4V VOUT = 3V IL = 100µA Quiescent Current (µA) Quiescent Current (µA) 50 Dropout Voltage Ground Pin Current Ground Pin Current 75 0 40 80 Temperature (°C) 40.00 30.00 20.00 10.00 0.00 0.1 125 10 20 30 40 50 Output Current (mA) Dropout Characteristics 3.5 Dropout Voltage 3.0 Dropout Voltage 8 100 Dropout Voltage (mV) Output Voltage (V) ROUT = 30KΩ 2.0 ROUT = 20Ω 1.5 1.0 0.5 0.0 0.0 1.0 2.0 3.0 4.0 6 4 IL = 100µA 2 0 -40 5.0 Dropout Voltage (mV) VOUT = 3V 2.5 Input Voltage (V) 0 40 80 Temperature (°C) 75 50 25 0 -40 125 IL = 50mA 0 40 80 Temperature (°C) 125 Output Voltage vs. Temperature Output Voltage (V) 3.05 3 2.95 VIN = 4V Typical 3V device IL = 100µA 2.9 2.85 -40 0 40 80 Temperature (°C) 125 Functional Characteristics Enable Shutdown Delay Disable Voltage (1V/div) Enable Voltage (1V/div) Enable Pin Delay Disable Output Voltage (1V/div) Output Voltage (1V/div) VOUT Time (20µs/div) 8 VOUT Time (20µs/div) REV. 1.0.6 2/14/03 FAN2508/FAN2509 PRODUCT SPECIFICATION Mechanical Dimensions 5-Lead SOT-23-5 (S) Package Inches Symbol A A1 B c D E e e1 H L α Millimeters Min. Max. Min. Max. .035 .000 .008 .003 .106 .059 .057 .006 .90 .00 .20 .08 2.70 1.50 1.45 .15 .020 .010 .122 .071 .037 BSC .075 BSC .087 .126 .004 .024 0° 10° Notes: Notes 1. Package outline exclusive of mold flash & metal burr. 2. Package outline exclusive of solder plating. 3. EIAJ Ref Number SC-74A. .50 .25 3.10 1.80 .95 BSC 1.90 BSC 2.20 3.20 .10 .60 0° 10° e B L E H e1 c D A A1 REV. 1.0.6 2/14/03 9 PRODUCT SPECIFICATION FAN2508/FAN2509 Ordering Information Product Number VOUT Pin 4 Function Package Marking FAN2508SX FAN2508S25X Adj. Adjust AAA 2.5 Bypass AAE FAN2508S26X 2.6 Bypass AAG FAN2508S27X 2.7 Bypass AAJ FAN2508S28X 2.8 Bypass AAM FAN2508S285X 2.85 Bypass AAN FAN2508S30X 3.0 Bypass AAW FAN2508S33X 3.3 Bypass AA3 FAN2509S25X 2.5 Error output ABE FAN2509S26X 2.6 Error output ABG FAN2509S27X 2.7 Error output ABJ FAN2509S28X 2.8 Error output ABM FAN2509S285X 2.85 Error output ABN FAN2509S30X 3.0 Error output ABW FAN2509S33X 3.3 Error output AB3 Tape and Reel Information Quantity Reel Size Width 3000 7" 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 2/14/03 0.0m 005 Stock#DS30002508 2000 Fairchild Semiconductor Corporation