RT9033 3A Adjustable Output Voltage LDO Regulator General Description Features The RT9033 is a low dropout linear regulator designed for high output current applications with critical performance. The IC responds very fast to step changes in load, which is suitable for low voltage microprocessor applications. z High Current Capability : 3A z Low Dropout : 350mV at 3A μA Low Ground Current : 250μ Adjustable Output Voltage Extremely Low Output Capacitor Requirement Internal Over Current Protection Internal Over Temperature Protection RoHS Compliant and Halogen Free z z z The RT9033 uses an internal P-MOSFET as the pass device, which does not cause extra GND current in heavy load and dropout condition. The shutdown mode of low operation current makes the IC suitable for power-saving systems. z z z Applications z The RT9033 also works well with low-ESR ceramic capacitors, reducing the amount of board space necessary for power applications and consumes less than 1μA in shutdown mode. The other features include ultra low dropout voltage, high output accuracy, current limiting protection and over temperature protection. The RT9033 is available in the TO-263-5 package. z z z z Battery-Powered Equipment High Efficiency “Green” Computer Systems Automotive Electronics High Efficiency Linear Lower Supplies High Efficiency Lost-Regulator for Switching Supply Pin Configurations (TOP VIEW) Ordering Information RT9033 2 3 4 5 GND ADJ 1 VOUT Lead Plating System G : Green (Halogen Free and Pb Free) VIN Package Type M5 : TO-263-5 Note : Richtek products are : RoHS compliant and compatible with the current require- EN ` ments of IPC/JEDEC J-STD-020. ` Suitable for use in SnPb or Pb-free soldering processes. TO-263-5 Typical Application Circuit VIN VIN VOUT CIN 10µF R1 RT9033 Chip Enable ADJ EN GND Note : VOUT = VREF x (1+ DS9033-01 April 2011 VOUT COUT 10µF R2 R1 ) R2 www.richtek.com 1 RT9033 Function Pin Description Pin No. Pin Name Pin Function Enable Input Logic, Active High. When the EN goes to a logic low or floating, the 1 EN 2 VIN Power Supply Input Pin. 3 GND Ground Pin. 4 VOUT Regulator Output Pin. 5 ADJ Adjustable Output Pin device is in shutdown mode. Function Block Diagram VOUT VIN Buffer Amplifier Thermal EN + - Current Limiting Sensor ADJ VREF GND www.richtek.com 2 DS9033-01 April 2011 RT9033 Absolute Maximum Ratings z z z z z z z z z (Note 1) Supply Input Voltage, VIN ---------------------------------------------------------------------------------------------EN Input Voltage, EN --------------------------------------------------------------------------------------------------All Other Pins ------------------------------------------------------------------------------------------------------------Power Dissipation, PD @ TA = 25°C TO-263-5 ------------------------------------------------------------------------------------------------------------------Package Thermal Resistance (Note 2) TO-263-5, θJA ------------------------------------------------------------------------------------------------------------TO-263-5, θJC ------------------------------------------------------------------------------------------------------------Lead Temperature (Soldering, 10 sec.) ----------------------------------------------------------------------------Junction Temperature --------------------------------------------------------------------------------------------------Storage Temperature Range ------------------------------------------------------------------------------------------ESD Susceptibility (Note 3) HBM -----------------------------------------------------------------------------------------------------------------------MM -------------------------------------------------------------------------------------------------------------------------- Recommended Operating Conditions z z z z 6V 6V 0.3V to 6V 3.448W 29°C/W 7°C/W 260°C 150°C −65°C to 150°C 2kV 200V (Note 4) Supply Input Voltage, VIN ---------------------------------------------------------------------------------------------- 2.5V to 5.5V EN Input Voltage --------------------------------------------------------------------------------------------------------- 0V to 5.5V Junction Temperature Range ------------------------------------------------------------------------------------------ −40°C to 125°C Ambient Temperature Range ------------------------------------------------------------------------------------------ −40°C to 85°C Electrical Characteristics (VIN = 5V, VEN = VIN, CIN = COUT = 10μF (Ceramic), TA = 25°C unless otherwise specified) Parameter Symbol Test Conditions Min Typ Max Unit -- 250 -- μA Input Power Quiescent Current IQ Shutdown Current ISHDN VEN = GND -- 100 -- nA VREF VADJ = VOUT -- 1.24 -- V I OUT = 10mA −1 -- 1 % Reference Voltage Reference Voltage Reference Voltage Tolerance Regulation Line Regulation ΔVLINE I OUT = 10mA, (VOUT+1)<VIN<5V -- 0.06 0.5 % Load Regulation ΔVLOAD 10mA < IOUT < 3A, VIN = 5V -- 0.2 1 % Output Current Limit ILIM VIN = VOUT + 1 -- 4.5 5.5 A Dropout Voltage VDROP I OUT = 3A -- 350 600 mV Logic-Low Voltage VIL -- -- 0.4 Logic-High Voltage VIH 1.2 -- -- -- -- 20 Output Enable EN Threshold Enable Pin Current IEN VIN = VEN V μA To be continued DS9033-01 April 2011 www.richtek.com 3 RT9033 Parameter Symbol Test Conditions Min Typ Max Unit Thermal Protection Thermal Shutdown Temperature TSD -- 165 -- 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 high effective four layers thermal conductivity test board of JEDEC 51-7 thermal measurement standard. The case point of θJC is on the exposed pad for the package. The copper area as heat sink is 225mm2. Note 3. Devices are ESD sensitive. Handling precaution is recommended. Note 4. The device is not guaranteed to function outside its operating conditions. www.richtek.com 4 DS9033-01 April 2011 RT9033 Typical Operating Characteristics Ω, unless otherwise specified. CIN = COUT = 10uF/X7R, R1 = R2 = 130kΩ Output Voltage vs. Temperature 2.70 Quiescent Current vs. Temperature 350 VIN = 3.3V, IOUT = 0mA, VOUT = 2.5V VIN = 2.5V, VOUT = 1.24V 325 Quiescent Current (μA) Output Voltage (V) 2.65 2.60 2.55 2.50 2.45 2.40 2.35 300 275 250 225 200 175 2.30 150 -50 -25 0 25 50 75 100 125 -50 -25 0 Reference Voltage vs. Temperature 1.35 25 50 75 100 125 Temperature (°C) Temperature (°C) Current Limit vs. Temperature 4.5 VIN = 2.5V, VOUT = 1.24V VIN = 3.3V, VOUT = 2.5V 4.0 1.30 Current Limit (A) Reference Voltage (V) 1.33 1.28 1.25 1.23 1.20 3.5 3.0 2.5 1.18 2.0 1.15 -50 -25 0 25 50 75 100 -50 125 -25 En Pin Threshold Voltage vs. Temperature 1.3 1.1 Rising Falling 0.7 50 75 100 125 Dropout Voltage vs. Load Current VIN = 3.3V, VOUT = 2.5V 0.9 25 600 Dropout Voltage (mV) En Pin Threshold Voltage (V) 1.5 0 Temperature (°C) Temperature (°C) VOUT = 3.3V 500 400 TJ = 125°C 300 TJ = 25°C 200 TJ = −40°C 100 0.5 0 -50 -25 0 25 50 Temperature (°C) DS9033-01 April 2011 75 100 125 0 500 0.5 1000 1 1500 1.5 2000 2 2500 2.5 3000 3 Load Current (A) Load Current (mA) www.richtek.com 5 RT9033 Load Transient Response Load Transient Response IOUT (1A/Div) IOUT (2A/Div) VOUT (100mV/Div) VOUT (200mV/Div) VIN = 3.3V, VOUT = 2.5V IOUT = 0.25A to 1.25A VIN = 3.3V, VOUT = 2.5V IOUT = 0.25A to 3A Time (50μs/Div) Time (100μs/Div) Line Transient Response Line Transient Response VIN (1V/Div) VIN (1V/Div) VOUT (20mV/Div) VOUT (20mV/Div) VIN = 3.5V to 4.5V, VOUT = 2.5V IOUT = 50mA VIN = 3.5V to 4.5V, VOUT = 2.5V Time (100μs/Div) Time (100μs/Div) Current Limit Start Up IOUT = 250mA VEN (2V/Div) IOUT (1A/Div) VIN = 3.3V, VOUT = 2.5V Time (100μs/Div) www.richtek.com 6 VOUT (1V/Div) VIN = 3.3V, VOUT = 2.5V, IOUT = 500mA Time (100μs/Div) DS9033-01 April 2011 RT9033 Applications Information Input and Output Capacitor Selection Output Voltage Setting Like any low-dropout regulator, the external capacitors used with the RT9033 must be carefully selected for regulator stability and performance. Using a capacitor whose value is > 10μF on the RT9033 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 line- The RT9033 output voltage can provide 1.24V to 4.9V (dropout voltage maximum 0.6V) operating rating. To use two resistors to adjust the customer’ s ideal output voltage. Resistors can be large to up to 1MΩ, because of the very high impedance and low bias current of the sense comparator: The resistor values are calculated by : transient response. The output capacitor must meet both requirements for minimum amount of capacitance and ESR in all LDOs application. The RT9033 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 > 25mΩ on the RT9033 output ensures stability. The RT9033 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 RT9033 and returned to a clean analog ground. Region of of Stable Current Region StableCC OUT ESRvs. vs. Load Load Current OUTESR Region of Stable COUT ESR (Ω) 10 Unstable Region 1 Stable Region Simulation Verify VIN = 5V, VOUT = 2.5V CIN = COUT = 10uF/X7R R1 = R2 = 130kΩ 0.001 0 0.5 Chip Enable Operation The RT9033 goes into sleep mode when the Enable pin is in a logic low condition. During this condition, the pass transistor, error amplifier, and band gap are turned off, reducing the supply current to 0.1μA. The Enable pin can be directly tied to VIN to keep the part on. Current Limit The RT9033 contains an independent current limiter, which monitors and controls the pass transistor's gate voltage, limiting the output current to 4.5A (typ.). 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 ⎛ ΔGain Error ⎞ PSRR = 20 x Log ⎜ ⎟ (dB) ⎝ ΔSupply ⎠ Note that when heavy load measuring, Δsupply will cause Δtemperature. And Δtemperature will cause Δoutput voltage. So the heavy load PSRR measuring is including temperature effect. Thermal Considerations 0.1 0.01 R1 ⎞ ⎛ VOUT = VREF × ⎜ 1 + ⎟ ⎝ R2 ⎠ 1 1.5 2 Load Current (A) 2.5 3 For continuous operation, do not exceed absolute maximum operation junction temperature. 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 : Figure 1 DS9033-01 April 2011 www.richtek.com 7 RT9033 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 RT9033, the maximum operating junction temperature is 125°C. The junction to ambient thermal resistance θJA is layout dependent. As shown in Figure 2, RT9033 TO-2635 with 15mm x 15mm PCB copper area on the standard JEDEC 51-7 four layers thermal test board thermal resistance θJA is about 29°C/W. The maximum power dissipation at TA = 25°C can be calculated by following formula : PD(MAX) = (125°C − 25°C) / (29°C/W) = 3.448W for TO-263-5 packages Thermal Resistance vs. Copper Area Thermal Resistance (°C/W) 70 The maximum power dissipation depends on operating ambient temperature for fixed TJ(MAX) and thermal resistance θJA . For RT9033 packages, the Figure 3 of de-rating curves allows the designer to see the effect of rising ambient temperature on the maximum power allowed. 4.0 Maximum Power Dissipation (W) PD(MAX) = (TJ(MAX) − TA) / θJA Four Layer PCB 3.5 3.0 TO-263-5 2.5 2.0 1.5 1.0 0.5 0.0 0 25 50 75 100 125 Ambient Temperature (°C) Figure 3. Derating Curves for RT9033 Packages 60 Single Layer PCB 50 40 Four Layer PCB 30 20 10 TO-263-5 Package 0 0 50 100 150 200 250 300 350 400 2 PCB Copper Area (mm ) Figure 2. Thermal Resistance θJA vs. Copper Area of TO-263-5 Packages www.richtek.com 8 DS9033-01 April 2011 RT9033 Outline Dimension C D U B V E L1 L2 b e b2 A Symbol Dimensions In Millimeters Dimensions In Inches Min Max Min Max A 4.064 4.826 0.160 0.190 B 1.143 1.676 0.045 0.066 b 0.660 0.914 0.026 0.036 b2 0.305 0.584 0.012 0.023 C 1.143 1.397 0.045 0.055 D 9.652 10.668 0.380 0.420 E 8.128 9.652 0.320 0.380 e 1.524 1.829 0.060 0.072 L1 14.605 15.875 0.575 0.625 L2 2.286 2.794 0.090 0.110 U 6.223 Ref. 0.245 Ref. V 7.620 Ref. 0.300 Ref. 5-Lead TO-263 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. DS9033-01 April 2011 www.richtek.com 9