RT9020 500mA, Low Dropout, Low Noise Ultra-Fast With Soft Start CMOS LDO Regulator General Description The RT9020 is a high-performance, 500mA LDO regulator, offering extremely high PSRR and ultra-low dropout, ideal for portable RF and wireless applications with demanding performance and space requirements. The RT9020 quiescent current is as low as 25A, further prolonging the battery life. The RT9020 also works with low-ESR ceramic capacitors, reducing the amount of board space necessary for power applications, critical in handheld wireless devices. The RT9020 consumes typical 0.7A in shutdown mode and has fast turn-on time less than 70s (without CSS). The other features include ultra-low dropout voltage, high output accuracy, current limiting protection, and high ripple rejection ratio. Tiny packages SOT-23-5 and SC-70-5 are available. Ordering Information RT9020 Package Type B : SOT-23-5 U5 : SC-70-5 Lead Plating System P : Pb Free G : Green (Halogen Free and Pb Free) Fixed Output Voltage 15 : 1.5V 16 : 1.6V : 32 : 3.2V 33 : 3.3V 1B : 1.25V 1H : 1.85V 2H : 2.85V Note : Richtek products are : Features Wide Operating Voltage Ranges : 2.2V to 5.5V Low Dropout : 250mV at 500mA 5mA Discharge Current of VOUT when IC Shutdown Ultra-Low-Noise for DSC Application Ultra-Fast Response in Line/Load Transient Current Limiting Protection Thermal Shutdown Protection High Power Supply Rejection Ratio Output Only 1 F Capacitor Required for Stability TTL-Logic-Controlled Shutdown Input RoHS Compliant and 100% Lead (Pb)-Free Applications Digital Still Camera CDMA/GSM Cellular Handsets Portable Information Appliances Laptop, Palmtops, Notebook Computers Mini PCI & PCI-Express Cards PCMCIA & New Cards Marking Information For marking information, contact our sales representative directly or through a Richtek distributor located in your area. Pin Configurations TOP VIEW VOUT SS 5 4 2 3 VIN GND EN SOT-23-5 / SC-70-5 RoHS compliant and compatible with the current requirements of IPC/JEDEC J-STD-020. Suitable for use in SnPb or Pb-free soldering processes. DS9020-04 April 2011 www.richtek.com 1 RT9020 Typical Application Circuit VIN VIN VOUT CIN 1uF/ X7R SS EN VOUT 1uF/ X7R RT9020 Chip Enable COUT GND CSS 0.5nF Functional Pin Description Pin Number Pin Name Pin Function 1 VIN Supply Input. 2 GND Common Ground. 3 EN 4 SS Soft Start. 5 VOUT Regulator Output. Enable Input Logic, Active High. When the EN goes to a logic low, the device will be shutdown. Function Block Diagram SS Current Limit POR OTP EN R VIN V REF + MOS Driver VOUT GND www.richtek.com 2 DS9020-04 April 2011 RT9020 Absolute Maximum Ratings (Note 1) Supply Input Voltage -----------------------------------------------------------------------------------------------------EN Input Voltage ----------------------------------------------------------------------------------------------------------Power Dissipation, PD @ TA = 25C SOT-23-5 -------------------------------------------------------------------------------------------------------------------SC-70-5 ---------------------------------------------------------------------------------------------------------------------Package Thermal Resistance (Note 2) SOT-23-5, JA --------------------------------------------------------------------------------------------------------------SC-70-5, JA ---------------------------------------------------------------------------------------------------------------Lead Temperature (Soldering, 10 sec.) ------------------------------------------------------------------------------Junction Temperature ----------------------------------------------------------------------------------------------------Storage Temperature Range -------------------------------------------------------------------------------------------ESD Susceptibility (Note 3) HBM -------------------------------------------------------------------------------------------------------------------------MM ---------------------------------------------------------------------------------------------------------------------------- Recommended Operating Conditions 6V 6V 0.4W 0.3W 250C/W 333C/W 260C 150C -65C to 150C 2kV 200V (Note 4) Supply Input Voltage ------------------------------------------------------------------------------------------------------ 2.2V to 5.5V Junction Temperature Range -------------------------------------------------------------------------------------------- -40C to 125C Ambient Temperature Range -------------------------------------------------------------------------------------------- -40C to 85C Electrical Characteristics (VIN = VOUT + 0.5V, VEN = VIN, CIN = COUT = 1F (Ceramic), TA = 25C unless otherwise specified) Parameter Symbol Test Conditions Min Typ Max Unit 2.2 -- 5.5 V Input Voltage Range VIN Output Noise Voltage VON VOUT = 1.5V, COUT = 1F, IOUT = 0mA, CSS = 1nF -- 40 -- V RMS Output Voltage Accuracy (Fixed Output Voltage) V OUT IOUT = 10mA -2 0 +2 % Quiescent Current IQ VEN = 5V, IOUT = 0mA -- 25 50 A Standby Current ISTBY VEN = 0V -- 0.7 1.5 A Current Limit ILIM RLOAD = 0, 2.2V V IN < 2.6V 0.4 0.7 1.05 A RLOAD = 0, 2.7V V IN 5.5V 0.5 0.8 1.05 A IOUT = 400mA, 2.2V V IN < 2.7V -- 160 320 IOUT = 500mA, 2.7V V IN 5.5V -- 250 400 -- -- 0.6 Dropout Voltage (Note 5) (Note 6) Load Regulation (Note 7) (Fixed Output Voltage) Soft Start Time VDROP V LOAD 1mA < IOUT < 400mA 2.2V VIN < 2.7V 1mA < IOUT < 500mA 2.7V VIN 5.5V VOUT = 2.5V, CSS = 1nF mV % -- -- 1 -- 0.7 1 ms To be continued DS9020-04 April 2011 www.richtek.com 3 RT9020 Parameter EN Threshold Symbol Test Conditions Min Typ Max Unit Logic-Low Voltage VIL 0 -- 0.6 Logic-High Voltage VIH 1.6 -- 5.5 0.1 1 5 A V Enable Pin Current IEN Power Supply Rejection Rate PSRR IOUT = 10mA -- -55 -- dB Line Regulation V LINE VIN = (VOUT+0.5) to 5.5V, IOUT = 1mA -- 0.01 0.2 %/V Thermal Shutdown Temperature TSD -- 170 -- Thermal Shutdown Hysteresis T SD -- 30 -- f = 10kHz C Note 1. 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 2. JA is measured in the natural convection at TA = 25C on a low effective thermal conductivity test board of JEDEC 513 thermal measurement standard. Note 3. Devices are ESD sensitive. Handling precaution recommended. Note 4. 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 IQ = IIN - IOUT under no load condition (IOUT = 0mA). The total current drawn from the supply is the sum of the load current plus the ground pin current. Note 6. The dropout voltage is defined as VIN -VOUT, which is measured when VOUT is VOUT(NORMAL) - 100mV. Note 7. Regulation is measured at constant junction temperature by using a 2ms current pulse. Devices are tested for load regulation in the load range from 10mA to 500mA. www.richtek.com 4 DS9020-04 April 2011 RT9020 Typical Operating Characteristics (CIN = COUT = 1uF/X7R, CSS = 1nF, unless otherwise specified) Output Voltage vs. Temperature 3.40 Dropout Voltage vs. Load Current 300 VIN = 5.0V 250 Dropout Voltage (mV) Output Voltage (V) 3.35 VOUT = 3.3V 3.30 3.25 3.20 3.15 3.10 TJ = 125C 200 TJ = 25C 150 TJ = -40C 100 50 0 -50 -25 0 25 50 75 100 125 0 100 Temperature (C) 200 500 Soft Start Time 10000 10 VIN = 4.5V, VOUT = 3.3V 40 (ms) Soft Start Time (us) Quiescent Current (uA) 400 Load Current (mA) Quiescent Current vs. Temperature 50 300 30 20 10 VIN = 5.0V, VOUT = 3.3V 8000 8 6000 6 4000 4 2000 2 0 0 -50 -25 0 25 50 75 100 0 125 Temperature (C) 3 4 5 6 7 8 9 10 EN Pin Shutdown Response VIN = 4.5V, VOUT = 3.3V, No Load VIN = 4.5V, VOUT = 3.1V, CSS = 22nF, No Load VEN (5V/Div) VEN (5V/Div) VOUT (1V/Div) IIN (50mA/Div) VOUT (2V/Div) IIN (50mA/Div) DS9020-04 April 2011 2 Css (nF) Start Up Time (10ms/Div) 1 Time (5ms/Div) www.richtek.com 5 RT9020 Load Transient Response Load Transient Response VIN = 4.5V, VOUT = 3.1V, ILOAD = 1mA to 300mA VIN = 4.5V, VOUT = 3.1V, ILOAD = 50mA to 250mA I LOAD (200mA/Div) I LOAD (200mA/Div) VOUT (100mV/Div) VOUT (100mV/Div) Time (250s/Div) Time (10s/Div) Line Transient Response Line Transient Response VIN = 4V to 5V, VOUT = 3.1V, ILOAD = 10mA VIN = 4V to 5V, VOUT = 3.1V, ILOAD = 100mA 5 5 VIN (V) 4 VIN (V) 4 VOUT (10mV/Div) VOUT (10mV/Div) 20 10 Time (100s/Div) Time (100s/Div) PSRR Noise VIN = 4.5V, VOUT = 3.3V VIN,AC = 100m VP-P VIN = 4.5V (By battery), VOUT = 3.3V, No Load 300 0 ILOAD = 100mA 200 Noise (V/Div) PSRR(dB) -10 -20 -30 -40 100 0 -100 -200 -50 ILOAD = 10mA -60 -300 -70 0.01 10 0.1 100 1 1000 10 10000 100 100000 1000 1000000 Time (10ms/Div) Frequency (Hz) Frequency (kHz) www.richtek.com 6 DS9020-04 April 2011 RT9020 Applications Information Like any low-dropout regulator, the external capacitors used with the RT9020 must be carefully selected for regulator stability and performance. The recommended input and output capacitors should be 1F or greater X7R/X5R ceramic.The input capacitor must be located a distance not more than 0.5 inch from the input pin of the IC and returned to a clean analog ground. The capacitor with larger value and lower ESR (equivalent series resistance) provides better PSRR and line-transient response. The output capacitor must meet both requirements for minimum amount of capacitance and ESR in all LDOs application. The RT9020 is designed specifically to work with low ESR ceramic output capacitor in space-saving and performance consideration. Using a ceramic capacitor whose value is at least 1F with ESR > 20m on the RT9020 output ensures stability. The RT9020 still works well with output capacitor of other types due to the wide stable ESR range. Figure 1. shows the curves of allowable ESR range as a function of load current for various output capacitor values. Output capacitor of larger capacitance can reduce noise and improve load transient response, stability, and PSRR. The output capacitor should be located not more than 0.5 inch from the VOUT pin of the RT9020 and returned to a clean analog ground. Region of Stable COUT ESR vs. Load Current Region of Stable COUT ESR () 100 The RT9020 goes into shutdown mode when the EN pin is in a logic low condition. During this condition, the RT9020 has an EN pin to turn on or turn off regulator, When the EN pin is logic high, the regulator will be turned on. The supply current in shutdown mode is as low as 0.7A typically. The EN pin may be directly tied to VIN to keep the part on. PSRR The power supply rejection ratio (PSRR) is defined as the gain from the input to output divided by the gain from the supply to the output. The PSRR is found to be PSRR = 20 x log Gain Error Supply Note that when heavy load measuring, supply will cause temperature. And temperature will cause output voltage change. So the heavy load PSRR measuring includes temperature effect. Current limit The RT9020 contains an independent current limiter, which monitors and controls the pass transistor's gate voltage, limiting the output current to 0.7A (typ.). The output can be shorted to ground indefinitely without damaging the part. Thermal Considerations Thermal protection limits power dissipation in RT9020. When the operation junction temperature exceeds 170C, the OTP circuit starts the thermal shutdown function and turns the pass element off. The pass element turn on again after the junction temperature cools by 30C. Unstable Range 10 Stable Range 1 0.1 Unstable Range by Simulation 0.01 0.001 Enable RT9020-33PB, VIN = 5V CIN = COUT = 1F/X7R 0 100 200 300 Load Current (mA) Figure 1 DS9020-04 April 2011 400 500 For continuous operation, do not exceed absolute maximum operation junction temperature 125C. The power dissipation definition in device is : PD = (VIN - VOUT) x IOUT + VIN x IQ The maximum power dissipation depends on the thermal resistance of IC package, PCB layout, the rate of surroundings airflow and temperature difference between junction to ambient. The maximum power dissipation can be calculated by following formula : PD(MAX) = ( TJ(MAX) - TA ) /JA www.richtek.com 7 RT9020 Where T J(MAX) is the maximum operation junction temperature, TA is the ambient temperature and the JA is the junction to ambient thermal resistance. For recommended operating conditions specification of RT9020, where T J(MAX) is the maximum junction temperature of the die (125C) and TA is the operated ambient temperature. The junction to ambient thermal resistance JA (JA is layout dependent) for SOT-23-5 package is 250C/W and SC-70-5 package is 333C/W on the standard JEDEC 51-3 single-layer thermal test board. The maximum power dissipation at TA = 25C can be calculated by following formula : PD(MAX) = (125C - 25C) / 250 = 0.400 W for SOT-23-5 packages PD(MAX) = (125C - 25C) / 333 = 0.300 W for SC-70-5 packages The maximum power dissipation depends on operating ambient temperature for fixed T J(MAX) and thermal resistance JA. For RT9020 packages, the Figure 2 of derating curves allows the designer to see the effect of rising ambient temperature on the maximum power allowed. 0.7 Single Layer PCB Power Dissipation (W) 0.6 0.5 SOT-23-5 0.4 0.3 SC-70-5 0.2 0.1 0 0 12.5 25 37.5 50 62.5 75 87.5 100 113 125 Ambient Temperature (C) Figure 2. Derating Curves for RT9020 Packages www.richtek.com 8 DS9020-04 April 2011 RT9020 Outline Dimension H D L B C b A A1 e Dimensions In Millimeters Dimensions In Inches Symbol Min Max Min Max A 0.889 1.295 0.035 0.051 A1 0.000 0.152 0.000 0.006 B 1.397 1.803 0.055 0.071 b 0.356 0.559 0.014 0.022 C 2.591 2.997 0.102 0.118 D 2.692 3.099 0.106 0.122 e 0.838 1.041 0.033 0.041 H 0.080 0.254 0.003 0.010 L 0.300 0.610 0.012 0.024 SOT-23-5 Surface Mount Package DS9020-04 April 2011 www.richtek.com 9 RT9020 H D L B C b A A1 e Dimensions In Millimeters Dimensions In Inches Symbol Min Max Min Max A 0.800 1.100 0.031 0.044 A1 0.000 0.100 0.000 0.004 B 1.150 1.350 0.045 0.054 b 0.150 0.400 0.006 0.016 C 1.800 2.450 0.071 0.096 D 1.800 2.250 0.071 0.089 e 0.650 0.026 H 0.080 0.260 0.003 0.010 L 0.210 0.460 0.008 0.018 SC-70-5 Surface Mount Package Richtek Technology Corporation Richtek Technology Corporation Headquarter Taipei Office (Marketing) 5F, No. 20, Taiyuen Street, Chupei City 5F, No. 95, Minchiuan Road, Hsintien City Hsinchu, Taiwan, R.O.C. Taipei County, Taiwan, R.O.C. Tel: (8863)5526789 Fax: (8863)5526611 Tel: (8862)86672399 Fax: (8862)86672377 Email: marketing@richtek.com Information that is provided by Richtek Technology Corporation is believed to be accurate and reliable. Richtek reserves the right to make any change in circuit design, specification or other related things if necessary without notice at any time. No third party intellectual property infringement of the applications should be guaranteed by users when integrating Richtek products into any application. No legal responsibility for any said applications is assumed by Richtek. www.richtek.com 10 DS9020-04 April 2011