RT A, Ultra-Low Dropout, Ultra-Fast CMOS LDO Regulator. General Description. Features. Applications. Ordering Information. Marking Information

Transcription

1 RT987 A, Ultra-Low Dropout, Ultra-Fast CMOS LDO Regulator General Description The RT987 is a high-performance, A LDO regulator, offering extremely high PSRR and ultra-low dropout. Ideal for portable RF and wireless applications with demanding performance and space requirements. A noise reduction pin is also available for further reduction of output noise. Regulator ground current increases only slightly in dropout, further prolonging the battery life. The RT987 also works with low-esr ceramic capacitors, reducing the amount of board space necessary for power applications, critical in hand-held wireless devices. The RT987 consumes less than.μa in shutdown mode and has fast turn-on time less than μs. The other features include ultra-low dropout voltage, high output accuracy, current limiting protection, and high ripple rejection ratio. Available in the VDFN-8L 3x3 and SOP-8 (Exposed Pad) package. Ordering Information RT987( - ) Package Type QV : VDFN-8L 3x3 (V-Type) SP : SOP-8 (Exposed Pad-Option ) Lead Plating System P : Pb Free G : Green (Halogen Free and Pb Free) None : Adjustable Output Fixed Code :.V :.V : 3 : 3.V 33 : 3.3V L :.3V Note : Richtek products are : RoHS compliant and compatible with the current requirements of IPC/JEDEC J-STD-. Suitable for use in SnPb or Pb-free soldering processes. Features Ultra-Low-Noise for RF Application Ultra-Fast Response in Line/Load Transient Quick Start-Up (Typically μs) <.μa Standby Current When Shutdown Low Dropout : mv at A Wide Operating Voltage Ranges :.5V to 5.5V TTL-Logic-Controlled Shutdown Input Current Limiting Protection Thermal Shutdown Protection Only.μF Output Capacitor Required for Stability High Power Supply Rejection Ratio RoHS Compliant and % Lead (Pb)-Free Applications CDMA/GSM Cellular Handsets Battery-Powered Equipment Laptop, Palmtops, Notebook Computers Hand-Held Instruments Mini PCI & PCI-Express Cards PCMCIA & New Cards Portable Information Appliances Marking Information For marking information, contact our sales representative directly or through a RichTek distributor located in your area. Pin Configuration (TOP VIEW) 3 9 VDFN-8L 3x NC BP/ADJ NC BP/ADJ SOP-8 (Exposed Pad) Copyright 7 Richtek Technology Corporation. All rights reserved. DS987-3 April 7

2 RT987 Typical Application Circuit V IN C IN.µF Chip Enable RT987 BP C OUT.µF C BP nf V OUT V IN C IN.µF Chip Enable RT987 ADJ R R C OUT.µF V OUT Figure. Fixed Operation Figure. Adjustable Operation V =.8 x ( OUT R R ) Volts Note : The value of R should be less than 8k to maintain regulation. Function Pin Description Fixed Output Voltage Pin No. Adjustable Pin Name Supply input. Pin Function Supply input. 3 3 Regulator output. Regulator output BP -- 5 ADJ Noise reduction. Connecting a nf capacitor to to reduce output noise. If external feedback resistors are applied, the output voltage will be: R =.8 (+ ) V R 6, 9 (Exposed Pad) 6, 9 (Exposed Pad) Ground. The exposed pad must be soldered to a large PCB and connected to for maximum power dissipation. 7 7 NC No internal connection. 8 8 Enable input logic, active high. When the goes to a logic low, the device is in shutdown mode. Copyright 7 Richtek Technology Corporation. All rights reserved. DS987-3 April 7

3 RT987 Functional Block Diagram OTP POR BIAS V REF - + Current Limit Quick start ADJ Adjustable OTP POR BIAS V REF - + Current Limit BP Quick start Fixed Copyright 7 Richtek Technology Corporation. All rights reserved. DS987-3 April 7 3

4 RT987 Absolute Maximum Ratings (Note ) Supply Input Voltage V Input Voltage V Power Dissipation, P T A = 5 C VDFN-8L 3x W SOP-8 (Exposed Pad) W Package Thermal Resistance (Note ) VDFN-8L 3x3, θ JC C/W VDFN-8L 3x3, θ JA C/W SOP-8 (Exposed Pad), θ JC C/W SOP-8 (Exposed Pad), θ JA C/W Lead Temperature (Soldering, sec.) C Junction Temperature C Storage Temperature Range C to 5 C ESD Susceptibility (Note 3) HBM kv MM V Recommended Operating Conditions (Note ) Supply Input Voltage V to 5.5V Input Voltage V to 5.5V Junction Temperature Range C to 5 C Ambient Temperature Range C to 85 C Electrical Characteristics ( = + V, V =, CIN = COUT =.μf (Ceramic) & CBP = nf, TA = 5 C unless otherwise specified) Parameter Symbol Test Conditions Min Typ Max Unit Accuracy (Fixed ) IOUT = ma.5.5 % Range (Adjustable) _Adj V Quiescent Current (Note 5) IQ V VIH, IOUT = ma A Standby Current (Note 6) ISTBY V VIL, = 3.3V --. A Current Limit ILIM RLOAD =.5, = 3.3V.8 3 A IOUT =.5A (Note 9) -- 6 Dropout Voltage (Note 7) VDROP IOUT =.5A -- 8 mv IOUT =.A Load Regulation (Note 8) (Fixed ) VLOAD = ( +.5V) %/A ma < IOUT <.A Logic-Low VIL = 3.3V Threshold Voltage V Logic-High VIH = 3.3V Enable Pin Current I = 3.3V, enable --. A Copyright 7 Richtek Technology Corporation. All rights reserved. DS987-3 April 7

5 RT987 Power Supply Rejection Rate Line Regulation Parameter Symbol Test Conditions Min Typ Max Unit f = Hz PSRR IOUT = 3mA f = khz V LINE V IN = (V OUT +.5) to 5.5V, I OUT = ma Note. Stresses listed as the above Absolute Maximum Ratings may cause permanent damage to the device. These are for stress ratings. Functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may remain possibility to affect device reliability. Note. θ JA is measured in natural convection at T A = 5 C on a high effective thermal conductivity four-layer test board of JEDEC 5-7 thermal measurement standard. The measurement case position of θ JC is on the exposed pad of the package. Note 3. Devices are ESD sensitive. Handling precaution is recommended. Note. The device is not guaranteed to function outside its operating conditions. Note 5. Quiescent, or ground current, is the difference between input and output currents. It is defined by I Q = I IN - I OUT under no load condition (I OUT = ma). The total current drawn from the supply is the sum of the load current plus the ground pin current. Note 6. Standby current is the input current drawn by a regulator when the output voltage is disabled by a shutdown signal (V >.8V ). Note 7. The dropout voltage is defined as V IN V OUT, which is measured when V OUT is V OUT(NORMAL) Σ mv. Note 8. Regulation is measured at constant junction temperature by using a ms current pulse. Devices are tested for load regulation in the load range from ma to.a. Note 9. Performance at -5 C T A 85 C is assured by design. db % Start-Up Time TStart_Up RLOAD = 3, nf CBP. F s Thermal Shutdown Temperature TSD Thermal Shutdown Hysteresis TSD ADJ Reference Voltage Tolerance VREF V ADJ Pin Current IADJ VADJ = VREF -- na C Copyright 7 Richtek Technology Corporation. All rights reserved. DS987-3 April 7 5

6 RT987 Typical Operating Characteristics (C OUT =.μf/x5r, C BP = nf, unless otherwise specified ) Quiescent Current vs. Temperature 5 = 3.3V 5 Quiescent Current vs. Input Voltage = 3.3V Quiescent Current (ua) 3 Quiescent Current (ua) Temperature ( C) Input Voltage (V) Dropout Voltage (mv) Dropout Voltage vs. Load Current =.8V TJ = 5 C TJ = 5 C TJ = - C Output Current (A) 5 3 = 3.3V Current Limit Load Current (A) Time (ms/div) (V) Pin Voltage (V) 5 Pin Shutdown Response = 3.3V, ILOAD : 56mA (V) Pin Voltage (V) Start Up = 3.3V ILOAD : 56mA Time (us/div) Time (5us/Div) Copyright 7 Richtek Technology Corporation. All rights reserved. 6 DS987-3 April 7

7 RT987 Line Transient Response Line Transient Response Input Voltage Deviation (V) = 3.3V to.3v, ILOAD : A Input Voltage Deviation (V) = 3.3V to.3v, ILOAD : 8mA Deviation (mv) - Deviation (mv) - Time (5us/Div) Time (5us/Div) Load Transient Response Load Transient Response Deviation (mv) Load Current (A) - = 3.3V, ILOAD : 5mA to A Deviation (mv) Load Current (A) 5-5 = 3.3V, ILOAD : 5mA to 8mA (A/Div) (5mV/Div) Time (us/div) Time (us/div) PSRR (db) = V = 3.8V ILOAD = 8mA ILOAD = ma PSRR Region of Stable COUT C OUT ESR (Ω) (Ω) Region of Stable C OUT ESR vs. Load Current = 3.3V Unstable Range = 6.V Stable Range k. k. k.. M. M Frequency (Hz) Load Current (A) Copyright 7 Richtek Technology Corporation. All rights reserved. DS987-3 April 7 7

8 RT987 Outline Dimension D D L E E SEE DETAIL A e b A A A3 DETAIL A Pin # ID and Tie Bar Mark Options Note : The configuration of the Pin # identifier is optional, but must be located within the zone indicated. Symbol Dimensions In Millimeters Dimensions In Inches Min Max Min Max A A..5.. A b D D E E e.65.6 L V-Type 8L DFN 3x3 Package Copyright 7 Richtek Technology Corporation. All rights reserved. 8 DS987-3 April 7

9 RT987 A H M EXPOSED THERMAL PAD (Bottom of Package) J Y X B F I C D Symbol Dimensions In Millimeters Dimensions In Inches Min Max Min Max A B C D F H I J M Option Option X Y X Y Lead SOP (Exposed Pad) Plastic Package Richtek Technology Corporation F, No. 8, Tai Yuen st Street, Chupei City Hsinchu, Taiwan, R.O.C. Tel: (8863) Richtek products are sold by description only. Customers should obtain the latest relevant information and data sheets before placing orders and should verify that such information is current and complete. Richtek cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Richtek product. Information furnished by Richtek is believed to be accurate and reliable. However, no responsibility is assumed by Richtek or its subsidiaries for its use; nor for any infringements 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 Richtek or its subsidiaries. DS987-3 April 7 9