Dual Input 3A Ultra Low Dropout Voltage Regulator

Transcription

1 Dual Input 3A Ultra Low Dropout Voltage Regulator Product Description The series LDOs are Dual Input Ultra Low Dropout linear voltage regulators that provide low-voltage (V REF = 0.8V), high-current output (3A). The Series offers extremely low dropout (typically 260mA at 3A). The are fixed and adjustable regulators, respectively, in a thermally enhanced power 8-lead PSOP (small outline package). Features Fixed and adjustable output voltages to 0.8V 260mV typical dropout at 3A Ideal for 1.8V to 1.2V conversion 3A minimum guaranteed output current 1.5% initial accuracy Low ground current Current limiting and thermal shutdown Reversed-battery protection Reversed-leakage protection Ultra Fast transient response RoHS Compliant, 100%Pb & Halogen Free Applications PC (Motherboard / Notebook / Net book) Applications DDR BUS VTT High-efficiency linear power supplies SMPS post regulator Multimedia and PC processor supplies Battery chargers Low Voltage Micro-Controllers and digital logic Notebook PC Applications Motherboard Applications Function Block Diagram 1

2 Ordering Information Part Number Package Q ty / Reel PSF PSOP-8 2.5K FF DFN-10 3K Marking Information PSOP-8 DFN-10 Pin Configurations & Description (Top View) PSF Series FF Pin Name PSF FF Pin Function POK 1 5 Power Good Open Drain Output EN 2 6 Chip Enable (Active High). V IN 3 7,8,9 Supply Voltage for major power V CNTL 4 10 Supply Voltage for Control Circuit. NC 5 - No Connect. V OUT 6 1,2,3 Output Voltage FB 7 4 Feedback Voltage. Note 1. GND 8 11 Ground Note1. For adjustable version parts a resistor divider on this pin sets the output voltage according to the relation: V OUT =0.8 X (R1 + R2) / R2. 2

3 Absolute Maximum Ratings Supply Voltage V IN -0.3V~6V Control Input Voltage V CNTL -0.3V~6V Other Pins -0.3V to (V CNTL + 0.3V) Power Dissipation, P T A =25 C 1.8W Thermal Resistance, θ JA (PSOP-8L) 40 C/W Thermal resistance between junction and case, θ JC (PSOP-8L) 17 ºC/W Lead Temperature (Soldering, 10 sec) 260 C Storage Temperature Range -65 C to 150 C ESD Rating HBM 2KV MM 200V Recommended Operating Conditions Symbol Parameter Range Unit V CNTL V CNTL Supply Voltage 3.0 ~ 5.5 V V IN V IN Supply Voltage 1.2 ~ 3.65 V V OUT V OUT Output Voltage (when V CNTL -V OUT >1.9V) V CNTL = 3.3V 0.8 ~ 1.2 V CNTL = 5.0V 0.8 ~ V IN V DROP,3V(Max) I OUT V OUT Output Current 0 ~ 33V A T J Junction Temperature -40 ~ 125 ºC T A Ambient Temperature Range -40 ~ 85 ºC V Electrical Characteristics V EN =V CNTL =5V, T A =T J =25 C, unless otherwise specified. Symbol Parameters Condition Min Typ Max Units V CNTL Control Pin Voltage V OUT =V REF V V IN Power Input Voltage V OUT =V REF V V FB Feed Back Voltage I OUT =1mA V REG LINE Line Regulation V CNTL =3.3V~5.5V % REG LOAD Load Regulation I OUT =1mA to 3A % V DROP Dropout Voltage I OUT =3A, V CNTL =5V mv I Q Quiescent Current V CNTL =5.5V ma I LIM Current Limit A I SHORT Short Current V OUT =GND ma Enable V ENL Logic-Low Voltage V CNTL =5V 0.4 V V ENH Logic-High Voltage V CNTL =5V 1.2 V I EN EN Input Bias Current V EN =0V ua I SHDN V CNTL Shutdown Current V EN =0V - 1 ua T SS Soft-Start Interval ms Power OK V POKTH POK Rising Threshold % V POKHYS POK Hysteresis % POK Sink Capability I POK = 10mA V POK Delay ms 3

4 Typical Application Circuit 4

5 Application Information The is a high performance linear regulator specifically designed to deliver up to 3A output current with very low input voltage and ultra low dropout voltage. With dual-supply configuration. The operates with a wide input voltage V IN range from 1.0V to 5.5V and is ideal for applications where V OUT is very close to V IN. Current-Limit The contains an independent current limit and the short circuit current protection to prevent unexpected applications. The monitors the current flowing through the output NMOS and limits the maximum current to prevent devices from being damaged during over-current conditions. Short Current-limit The short current-limit function reduces the current-limit level down to 1.1A (typical) when the voltage on FB pin falls below 0.2V (typical) during current overload or short circuit conditions. The short current-limit function is disabled for successful start-up during soft-start interval. Thermal Shutdown Thermal protection limits power dissipation to prevent IC over temperature. When the operation junction temperature exceeds 150 C, the over-temperature protection circuit starts the thermal shutdown function and turns the pass transistor off. The pass transistor turns on again after the junction temperature cools by 30 C. It is highly recommended to keep the junction temperature below the recommended operation condition 125 C for maximum reliability. Enable Control The goes into shutdown mode when the EN pin is in the logic low condition. Output Capacitor The requires a proper output capacitor to maintain stability and improve transient response. The output capacitor selection is dependent upon ESR (equivalent series resistance) and capacitance of the output capacitor over the operating temperature. Ultra-low-ESR capacitors (such as ceramic chip capacitors) and low-esr bulk capacitors (such as solid tantalum, POSCap, and Aluminum electrolytic capacitors) can all be used as output capacitors. For the applications with large stepping load current, the low-esr bulk capacitors are normally recommended. Decoupling ceramic capacitors must be placed at the load and ground pins as close as possible and the impedance of the layout must be minimized. Input Capacitor Ultra-low-ESR capacitors (such as ceramic chip capacitors) and low-esr bulk capacitors (such as solid tantalum, POSCap, and Aluminum electrolytic capacitors) can all be used as an input capacitor of V IN. For most applications, the recommended input capacitance of V IN is 10µF at least. More capacitance reduces the variations of the supply voltage on V IN pin. Setting Output Voltage The output voltage is programmed by the resistor divider connected to FB pin. The preset output voltage is calculated by the following equation : Where R1 is the resistor connected from V OUT to FB with Kelvin sensing connection and R2 is the resistor connected from FB to GND. A bypass capacitor (C1) may be connected with R1 in parallel to improve load transient response and stability. Following a shutdown, a logic high signal re-enables the output through initiation of a new soft-start cycle. When left open, this pin is pulled up by an internal current source to enable normal operation. It s not necessary to use an external transistor to save cost. Power-OK and Delay The power good function is an open-drain output. Connects 10kΩ pull up resistor to V OUT to obtain an output voltage. The POK pin will output high immediately after the output voltage arrives 90% of normal output voltage. The POK pin will output high with typical 1.5ms delay time. 5

6 Package Information PSOP-8 PLASTIC PACKAGE Dimensions Millimeters Inches SYMBOL MIN MAX MIN MAX A A A b b c c D D (TYP).130 (TYP) E E E (TYP).094 (TYP) e 1.27 (TYP).050 (TYP) L L (TYP).041 (TYP) R R h θ θ θ

7 Package Information DFN-10 Dimensions Symbol Millimeters Inches Min Nom Max Min Nom Max A A A2 (0.13) (.005) b b D E e 0.50 BSC.020 BSC L N aaa bbb NOTES: 1. Controlling dimensions are in millimeters (angles in degrees). 7

8 Dimensions Symbol Millimeters Inches C (0.875) (.034) G P P X X Y Y1 (1.55) (.061) Z NOTES: 1. Controlling dimensions are in millimeters (angles in degrees). 2. This land pattern is for reference purposes only. Consult your manufacturing group to ensure your company s manufacturing guidelines are met. 8

9 NOTICE Information furnished is believed to be accurate and reliable. However Globaltech Semiconductor assumes no responsibility for the consequences of use of such information nor for any infringement of patents or other rights of third parties, which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of Globaltech Semiconductor. Specifications mentioned in this publication are subject to change without notice. This publication supersedes and replaces all information without express written approval of Globaltech Semiconductor. CONTACT US GS Headquarter 4F.,No.43-1,Lane11,Sec.6,Minquan E. Rd Neihu District Taipei City 114, Taiwan (R.O.C) Wu-Xi Branch No.21 Changjiang Rd., WND, Wuxi, Jiangsu, China (INFO. &. TECH. Science Park Building A 210 Room) sales_cn@gs-power.com 824 Bolton Drive Milpitas. CA RD Division Version_1.0a Notice