1A Ultra Low Dropout Linear Regulator TJ4940 FEATURES • • • • • • • • Ultra Low Dropout Voltage Compatible with low ESR MLCC as Input/Output Capacitor Good Line and Load Regulation Guaranteed Output Current of 1A Available in SOT-223 and TO-252 Packages Fixed Output Voltages : 1.0V, 1.2V, 1.8V, 2.5V, and 3.3V Over-Temperature/Over-Current Protection -40 ºC to 125 ºC Junction Temperature Range SOT-223 3L TO252 3L PKG APPLICATION • • • • • • • LCD TVs and SETTOP Boxes Battery Powered Equipments Motherboards and Graphic Cards Microprocessor Power Supplies Peripheral Cards High Efficiency Linear Regulators Battery Chargers ORDERING INFORMATION Device DESCRIPTION Package TJ4940xS-X.X The TJ4940 series of high performance ultra-low dropout linear regulators operates from 2.5V to 6V input supply and provides ultra-low dropout voltage, high output current with low ground current. Wide range of preset output voltage options are available. These ultra-low dropout linear regulators respond fast to step changes in load which makes them suitable for low voltage micro-processor applications. The TJ4940 is developed on a CMOS process technology which allows low quiescent current operation independent of output load current. This CMOS process also allows the TJ4940 to operate under extremely low dropout conditions. SOT-223 3L TJ4940GRS-X.X TO-252 3L X.X = Output Voltage = 1.0, 1.2, 1.8, 2.5, and 3.3 Absolute Maximum Ratings CHARACTERISTIC SYMBOL MIN. MAX. UNIT Input Supply Voltage (Survival) VIN - 6.5 V Maximum Output Current IMAX - 1 A Lead Temperature (Soldering, 5 sec) TSOL 260 ºC Storage Temperature Range TSTG -65 150 ºC Operating Junction Temperature Range TJOPR -40 125 ºC * Calculated from package in still air, mounted to 2.6mm X 3.5mm(minimum foot print) 2 layer PCB without thermal vias per JESD51 standards. Jul. 2011 – Preliminary 1/8 HTC 1A Ultra Low Dropout Linear Regulator TJ4940 Ordering Information VOUT 1.0V 1.2V 1.8V 2.5V 3.3V Package SOT-223 3L Order No. TJ4940S-1.0 Description Package Marking 1A 4940-1.0 Status Contact Us TO-252 3L TJ490GRS-1.0-3L 1A TJ4940G-1.0 Contact Us SOT-223 3L TJ4940S-1.2 1A 4940-1.2 Contact Us TO-252 3L TJ4940GRS-1.2-3L 1A TJ4940G-1.2 Contact Us SOT-223 3L TJ4940S-1.8 1A 4940-1.8 Contact Us TO-252 3L TJ4940GRS-1.8-3L 1A TJ4940G-1.8 Contact Us SOT-223 3L TJ4940S-2.5 1A 4940-2.5 Contact Us TO-252 3L TJ4940GRS-2.5-3L 1A TJ4940G-2.5 Contact Us SOT-223 3L TJ4940S-3.3 1A 4940-3.3 Contact Us TO-252 3L TJ4940GRS-3.3-3L 1A TJ4940G-3.3 Contact Us T J 4 9 4 0 G R S – x.x – 3 L Lead Count : 3L Output Voltage : 1.0V / 1.2V / 1.8V / 2.5V / 3.3V Package Type Material Class S : SOT - 223 RS : TO - 252 G : Halogen Free Blank : Pb Free Root Name Product Code Jul. 2011 – Preliminary 2/8 HTC 1A Ultra Low Dropout Linear Regulator TJ4940 PIN CONFIGURATION GND GND VOUT VIN VOUT VIN SOT-223 TO-252-3L PIN DESCRIPTION Pin No. SOT 223 / TO 252 3 LEAD Name Function 1 GND Ground 2 VOUT Output Voltage 3 VIN Input Voltage Jul. 2011 – Preliminary 3/8 HTC 1A Ultra Low Dropout Linear Regulator TJ4940 BASIC APPLICATION Typical 3 Pin Application VIN VIN VOUT VOUT TJ4940 CIN 10uF GND COUT 10uF * See Application Information. Jul. 2011 – Preliminary 4/8 HTC 1A Ultra Low Dropout Linear Regulator TJ4940 ELECTRICAL CHARACTERISTICS (Note 1) Limits in standard typeface are for TJ=25ºC, and limits in boldface type apply over the full operating temperature range. Unless otherwise specified: VIN(Note 2) = VO(NOM) + 1 V, IL = 10 mA, CIN = 10 uF, COUT = 10 uF, VEN = VIN - 0.3 V PARAMETER SYMBOL TEST CONDITION MIN. TYP. MAX. UNIT VO VOUT+1 V < VIN < 5.5 V -2 -3 0 2 3 % Line Regulation(Note 1) ΔVLINE VOUT+1 V < VIN < 5.5 V - 0.15 0.40 %/V Load Regulation(Note 1, 2) ΔVLOAD 10 mA < IL < 1 A - 0.20 0.50 0.60 % IL = 100 mA - 45 55 65 IL = 1 A - 400 500 600 IL = 100 mA - 0.40 0.6 1.0 Output Voltage Tolerance (Note 3) Dropout Voltage Ground Pin Current (Note 4) Power Supply Rejection Ratio Thermal Shutdown Temperature Thermal Shutdown Hysteresis VDROP IGND PSRR TSD mV mA IL = 1 A - 0.40 0.6 1.0 f = 1kHz - 55 - dB - - 165 - ºC - 10 - ºC ΔTSD Note 1. Output voltage line regulation is defined as the change in output voltage from the nominal value due to change in the input line voltage. Output voltage load regulation is defined as the change in output voltage from the nominal value due to change in load current. Note 2. Regulation is measured at constant junction temperature by using a 10ms current pulse. Devices are tested for load regulation in the load range from 10mA to 1A. Note 3. Dropout voltage is defined as the minimum input to output differential voltage at which the output drops 2% below the nominal value. Dropout voltage specification applies only to output voltages of 2.5V and above. For output voltages below 2.5V, the dropout voltage is nothing but the input to output differential, since the minimum input voltage is 2.5V Note 4. Ground current, or quiescent current, is the difference between input and output currents. It's defined by IGND1 = IIN - IOUT under the given loading condition. The total current drawn from the supply is the sum of the load current plus the ground pin current. Jul. 2011 – Preliminary 5/8 HTC 1A Ultra Low Dropout Linear Regulator TJ4940 APPLICATION INFORMATION Maximum Output Current Capability The TJ4940 can deliver a continuous current of 1A over the full operating junction temperature range. However, the output current is limited by the restriction of power dissipation which differs from packages. A heat sink may be required depending on the maximum power dissipation and maximum ambient temperature of application. With respect to the applied package, the maximum output current of 1A may be still undeliverable due to the restriction of the power dissipation of TJ4940. Under all possible conditions, the junction temperature must be within the range specified under operating conditions. The temperatures over the device are given by: TC = TA + PD X θCA / TJ = TC + PD X θJC / TJ = TA + PD X θJA where TJ is the junction temperature, TC is the case temperature, TA is the ambient temperature, PD is the total power dissipation of the device, θCA is the thermal resistance of case-to-ambient, θJC is the thermal resistance of junction-to-case, and θJA is the thermal resistance of junction to ambient. The total power dissipation of the device is given by: PD = PIN – POUT = (VIN X IIN)–(VOUT X IOUT) = (VIN X (IOUT+IGND)) – (VOUT X IOUT) = (VIN - VOUT) X IOUT + VIN X IGND where IGND is the operating ground current of the device which is specified at the Electrical Characteristics. The maximum allowable temperature rise (TRmax) depends on the maximum ambient temperature (TAmax) of the application, and the maximum allowable junction temperature (TJmax): TRmax = TJmax – TAmax The maximum allowable value for junction-to-ambient thermal resistance, θJA, can be calculated using the formula: θJA = TRmax / PD = (TJmax – TAmax) / PD TJ4940 is available in SOT-223, and TO-252 packages. The thermal resistance depends on amount of copper area or heat sink, and on air flow. If the maximum allowable value of θJA calculated above is as described in Table 1, no heat sink is needed since the package can dissipate enough heat to satisfy these requirements. If the value for allowable θJA falls near or below these limits, a heat sink or proper area of copper plane is required. Jul. 2011 – Preliminary 6/8 HTC 1A Ultra Low Dropout Linear Regulator TJ4940 Table. 1. Absolute Maximum Ratings of Thermal Resistance No heat sink / No air flow / No adjacent heat source / TA = 25°C Characteristic Symbol Rating Unit Thermal Resistance Junction-To-Ambient / SOT-223 θJA-SOT223 140 °C/W Thermal Resistance Junction-To-Ambient / TO-252 θJA-TO252 105 °C/W In case that there is no cooling solution and no heat sink / minimum copper plane area for heat sink, the maximum allowable power dissipation of each package is as follow; Characteristic Symbol Rating Unit Maximum Allowable Power Dissipation at TA=25°C / SOT-223 PDMax-SOT223 0.714 W Maximum Allowable Power Dissipation at TA=25°C / TO-252 PDMax-TO252 0.952 W - Please note that above maximum allowable power dissipation is based on the minimum copper plane area which does not exceed the proper footprint of the package. And the ambient temperature is 25°C. If proper cooling solution such as heat sink, copper plane area, air flow is applied, the maximum allowable power dissipation could be increased. However, if the ambient temperature is increased, the allowable power dissipation would be decreased. For example, in case of SOT-223 and TO-252 package, θJA-SOT223 is 140 °C/W and θJA-TO52 is 105 °C/W, however, as shown in below graph, θJA could be decreased with respect to the copper plane area. So, the specification of maximum power dissipation for an application is fixed, the proper copper plane area could be estimated by following graphs. As shown in graph, wider copper plane area leads lower θJA. Junction To Ambient Thermal Resistance, θJA vs. 1 ounce Copper Area [SOT-223 Package] Apr. 2010 – Preliminary Junction To Ambient Thermal Resistance, θJA vs. 2 ounce Copper Area [TO-252 Package] 7/8 HTC 1A Ultra Low Dropout Linear Regulator TJ4940 The maximum allowable power dissipation is also influenced by the ambient temperature. With the above θJA-Copper plane area relationship, the maximum allowable power dissipation could be evaluated with respect to the ambient temperature. As shown in graph, the higher copper plane area leads θJA. And the higher ambient temperature leads lower maximum allowable power dissipation. All this relationship is based on the aforesaid equation ; θJA = TRmax / PD = (TJmax – TAmax) / PD. T.B.D Jul. 2011 – Preliminary 8/8 HTC