RT9050 300mA, 0.5% Accuracy Low Dropout, Ultra Low Noise Voltage Regulator General Description The RT9050 is a high-performance, 300mA LDO regulator, offering extremely high PSRR and ultra-low dropout. The RT9050 is Ideal for portable RF and wireless applications with demanding performance and space requirements. The RT9050 provides quiescent current to be as low as 25μA to extend the battery life. The RT9050 also works with low-ESR ceramic capacitors, reducing the amount of board space necessary for power applications, especially for hand-held wireless devices. The RT9050 consumes typical 0.7μA in shutdown mode and has fast turn-on time to be less than 40μs. The other features include ultra-low dropout voltage, high output accuracy, current limiting protection, and high ripple rejection ratio. The RT9050 is available in the SOT-23-5 package. Ordering Information RT9050 Package Type B : SOT-23-5 Lead Plating System G : Green (Halogen Free and Pb Free) Features Wide Operating Voltage Range : 3.8V to 5.5V Low Dropout : 150mV at 300mA Ultra-Low-Noise without Bypass Capacitor Ultra-Fast in Line/Load Transient Response Current Limit Protection Thermal Shutdown Protection High Power Supply Rejection Ratio Only 1μ μF Output Capacitor Required for Stability TTL-Logic-Controlled Shutdown Input RoHS Compliant and Haloge Free Applications CDMA/GSM Cellular Handsets Portable Information Appliances Laptop, Palmtops, Notebook Computers Hand-Held Instruments Mini PCI & PCI-Express Cards PCMCIA & New Cards Pin Configurations (TOP VIEW) Fixed Output Voltage 33 : 3.3V VOUT NC 5 4 2 Note : Richtek products are : ` VIN GND EN RoHS compliant and compatible with the current require- SOT-23-5 ments of IPC/JEDEC J-STD-020. ` Suitable for use in SnPb or Pb-free soldering processes. Marking Information For marking information, contact our sales representative directly or through a Richtek distributor located in your area. DS9050-01 April 2011 3 Typical Application Circuit VIN CIN 1µF/X7R Chip Enable VIN VOUT RT9050 EN VOUT COUT 1µF/X7R GND Rpull_down 100k www.richtek.com 1 RT9050 Functional Pin Description Pin No. Pin Name Pin Function 1 VIN Power Supply Input. 2 GND Ground Pin. 3 EN 4 NC No Internal Connection. 5 VOUT Regulator Output. Chip Enable (Active High). It is recommended to add a 100kΩ resistor between the EN and GND. Function Block Diagram EN Current Limit POR OTP VIN VREF + MOS Driver VOUT GND Absolute Maximum Ratings (Note 1) Supply Input Voltage -----------------------------------------------------------------------------------------------------EN Input Voltage ----------------------------------------------------------------------------------------------------------Power Dissipation, PD @ TA = 25°C SOT-23-5 -------------------------------------------------------------------------------------------------------------------Package Thermal Resistance (Note 2) SOT-23-5, θJA --------------------------------------------------------------------------------------------------------------Lead Temperature (Soldering, 10 sec.) ------------------------------------------------------------------------------Junction Temperature ----------------------------------------------------------------------------------------------------Storage Temperature Range -------------------------------------------------------------------------------------------ESD Susceptibility (Note 3) HBM -------------------------------------------------------------------------------------------------------------------------MM ---------------------------------------------------------------------------------------------------------------------------- Recommended Operating Conditions 6V 6V 0.4W 250°C/W 260°C 150°C −65°C to 150°C 2kV 200V (Note 4) Supply Input Voltage ------------------------------------------------------------------------------------------------------ 3.8V to 5.5V Junction Temperature Range -------------------------------------------------------------------------------------------- −40°C to 125°C Ambient Temperature Range -------------------------------------------------------------------------------------------- −40°C to 85°C www.richtek.com 2 DS9050-01 April 2011 RT9050 Electrical Characteristics (VIN = VOUT + 0.5V, VEN = VIN, CIN = COUT = 1μF/X7R (Ceramic), TA = 25°C, unless otherwise specified) Parameter Output Noise Voltage Symbol Test Conditions VON Min Typ Max Unit -- 30 -- μVRMS Output Voltage Accuracy ΔVOUT 1mA ≤ IOUT ≤ 150mA, T J = 25°C −0.5 0 +0.5 % Quiescent Current IQ IOUT = 0mA -- 25 50 μA Shutdown Current ISHDN VEN = 0V -- 0.7 1.5 μA Current Limit ILIM RLOAD = 0Ω 300 400 600 mA (Note 5) Dropout Voltage (Note 6) VDROP IOUT = 300mA -- 125 240 mV Load Regulation (Note 7) ΔVLOAD 1mA < IOUT < 300mA -- -- 1 % Logic-Low Voltage VIL 0 -- 0.6 Logic-High Voltage VIH 1.6 -- 5.5 -- 0.1 1 μA EN Threshold V Enable Pin Current IEN Power Supply Rejection Rate PSRR IOUT = 100mA, f = 10kHz -- −50 -- dB Line Regulation ΔVLINE VIN = (V OUT + 0.5V) to 5.5V, IOUT = 1mA -- 0.01 0.2 %/V Thermal Shutdown Temperature T SD -- 170 -- Thermal Shutdown Hysteresis ΔTSD -- 30 -- °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. θJA is measured in the natural convection at TA = 25°C on a low effective thermal conductivity single layer test board of JEDEC 51-3 thermal measurement standard. Note 3. Devices are ESD sensitive. Handling precaution is 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 300mA. Note 8. The output voltage variation is typical ±0.5% within recommended operating temperature range. DS9050-01 April 2011 www.richtek.com 3 RT9050 Typical Operating Characteristics (CIN = COUT = 1μ/X7R, unless otherwise specified) Quiescent Current vs. Temperature Output Voltage vs. Temperature 30 3.34 28 Quiescent Current (uA) Output Voltage (V) 3.33 3.32 3.31 3.30 3.29 3.28 3.27 0 25 50 75 100 22 20 18 16 14 VIN = 4.2V 10 3.26 -25 24 12 VIN = 4.2V, VOUT = 3.3V, IOUT = 0mA -50 26 -50 125 -25 0 25 50 75 100 125 Temperature (°C) Temperature (°C) EN Pin Shutdown Response Dropout Voltage vs. Load Current 125°C Dropout Voltage (mV) 160 25°C 140 120 100 −40°C 80 60 40 20 VOUT = 3.3V 0 0 50 100 150 200 250 Output Voltage (V) 180 EN Pin Voltage (V) 200 VIN = 5V, VOUT = 3.3V, IOUT = 50mA 4 2 0 4 2 0 300 Time (100μs/Div) Load Current (mA) Line Transient Response VIN = 3.6V to 4.6V, IOUT = 10mA Input Voltage Deviation (V) 4 2 0 4 2 0 VIN = 5V, VOUT = 3.3V, IOUT = 50mA Time (5μs/Div) www.richtek.com 4 Output Voltage Deviation (mV) Output Voltage (V) EN Pin Voltage (V) Start Up 4.6 3.6 20 0 -20 Time (100μs/Div) DS9050-01 April 2011 RT9050 Line Transient Response Noise VIN = 4.5V (By Battery), No Load 300 4.6 Noise (μV/Div) Output Voltage Deviation (mV) Input Voltage Deviation (V) VIN = 3.6V to 4.6V, IOUT = 100mA 3.6 20 200 100 0 -100 0 -200 -20 -300 Time (10ms/Div) Time (100μs/Div) Noise VIN = 4.5V (By Battery), IOUT = 10mA VIN = 4.1V to 4.2V 10 300 0 200 -10 100 PSRR(dB) Noise (μV/Div) PSRR 20 0 -100 -20 -30 -40 -200 -50 -300 -60 IOUT = 100mA IOUT = 10mA -70 10 Time (10ms/Div) 100 1000 10000 100000 1000000 Frequency (Hz) Load Transient Response Load Transient Response Load Current (mA) 100 50 0 50 0 -50 Time (100μs/Div) DS9050-01 April 2011 VIN = 5V, VOUT = 3.3V, IOUT = 10mA to 300mA Output Voltage Deviation (mV) Output Voltage Load Current Deviation (mV) (mA) VIN = 5V, VOUT = 3.3V, IOUT = 10mA to 100mA 300 200 100 0 100 0 -100 Time (100μs/Div) www.richtek.com 5 RT9050 Applications Information Like any low-dropout regulator, the external capacitors used with the RT9050 must be carefully selected for regulator stability and performance. Using a capacitor whose value is > 1μF / X7R on the RT9050 input and the amount of capacitance can be increased without limit. The input capacitor must be located at a distance of not more than 0.5 inch from the input pin of the IC and returned to a clean analog ground. Any good quality ceramic can be used for this capacitor. 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 RT9050 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 1μF with ESR is > 20mΩ on the RT9050 output ensures stability. The RT9050 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 at not more than 0.5 inch from the VOUT pin of the RT9050 and returned to a clean analog ground. Enable The RT9050 goes into sleep mode when the EN pin is in a logic low condition. During this condition, the RT9050 has an EN pin to turn on or turn off the regulator, When the EN pin is in logic high, the regulator will be turned on. The shutdown current is 0.7μA typical. The EN pin may be directly tied to VIN to keep the part on. The Enable input is CMOS logic and cannot be left floating. 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 × log⎜ ΔGain Error ⎟ ⎝ ΔSupply ⎠ Note that in heavy load measuring, Δsupply will cause Δtemperature. And Δtemperature will cause Δoutput voltage. So the temperature effect is include in heavy load PSRR measuring. Current Limit The RT9050 contains an independent current limiter, which monitors and controls the pass transistor's gate voltage, limiting the output current to 0.4A (typ.). The output can be shorted to ground indefinitely without damaging the part. Thermal Considerations Region of Stable COUT ESR vs. Load Current RegionofofStable StableCCOUT OUT ESR Region ESR (Ω) (Ω) 100 Unstable Range 10 1 Stable Range For continuous operation, do not exceed absolute maximum operation junction temperature 125°C. The power dissipation definition in the device is calculated as follows : 0.1 0.01 Unstable Range VIN = 5V CIN = COUT = 1μF/X7R PD = (VIN − VOUT) x IOUT + VIN x IQ 0.001 0 50 100 Thermal protection limits power dissipation in the RT9050. When the operation junction temperature exceeds 170°C, the OTP circuit starts the thermal shutdown function and turns the pass element off. The pass element will be turned on again after the junction temperature cools by 30°C. 150 200 250 300 Load Current (mA) Figure 1 www.richtek.com 6 DS9050-01 April 2011 RT9050 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 ) /θJA Where T J(MAX) is the maximum operation junction temperature, TA is the ambient temperature and the θJA is the junction to ambient thermal resistance. For recommended operating conditions specification of the RT9050, the maximum junction temperature is 125°C. The junction to ambient thermal resistance for SOT-23-5 package is 250°C/W on the standard JEDEC 51-3 singlelayer thermal test board. The maximum power dissipation at TA = 25°C can be calculated by following formula : P D(MAX) = (125°C − 25°C) / (250°C/W) = 0.4W for SOT-23-5 package The maximum power dissipation depends on operating ambient temperature for fixed TJ(MAX) and thermal resistance θJA. For RT9050 package, the Figure 2 of derating curve allows the designer to see the effect of rising ambient temperature on the maximum power dissipation allowed. Maximum Power Dissipation (W) 0.50 Single Layer PCB 0.45 0.40 0.35 0.30 0.25 0.20 0.15 0.10 0.05 0.00 0 25 50 75 100 125 Ambient Temperature (°C) Figure 2. Derating Curve for RT9050 Package DS9050-01 April 2011 www.richtek.com 7 RT9050 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 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: [email protected] 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 8 DS9050-01 April 2011