SU1085 3A Low Dropout Positive Adjustable or Fixed-Mode Regulator Elektronische Bauelemente RoHS Compliant Product Description The SU1085 is a low dropout at positive adjustable or fixed-mode regulator with min. of 3A output current capability. The product is specifically designed to provide well-regulated supply for low voltage IC applications such as high-speed bus termination and low current 3.3V logic supply. SU1085 is also well suited for other applications such as VGA cards. SU1085 is guaranteed to have lower than 1.4V dropout at full load current making it ideal to provide well regulated outputs of 1.25V to 5V with 4.7 to 12V input supply by different output voltage. Features REF. * 1.4V Max. Dropout Full Load Current A b L4 c L3 L1 E * 3-Terminal Adjustable or Fixed 1.5V,1.8V,2.5V,3.3V,5.0V * Output Current Limiting * Fast Transient Response * Built-in Thermal Shutdown Millimeter REF. Min. Max. 4.40 4.80 c2 0.76 1.00 b2 0.00 0.30 B D 0.36 0.5 e 1.50 REF. L 2.29 2.79 9.80 10.4 L2 Millimeter Min. Max. 1.25 1.45 1.17 1.47 8.6 9.0 2.54 REF. 14.6 15.8 0˚ 8˚ 1.27 REF. Block Diagram Typical Circuit 3.3V/3A http://www.SeCoSGmbH.com/ 01-Jun-2002 Rev. A 2.5V/3A Any changing of specification will not be informed individual Page 1 of 4 SU1085 3A Low Dropout Positive Elektronische Bauelemente Adjustable or Fixed-Mode Regulator Pin Descriptions Name I/O PIN# Adj (GND) FUNCTION 1 Adjustable (Ground only for fixed mode) Vout O 2 The output of the regulator. A minimum of 10uF capacitor must be connected from this pin to ground to insure stability. Vin I 3 The input pin of regulator .Typically a large storage capacitor is connected from this pin to ground to insure that the input voltage does during thethe load s not sag sag below belowthe theminimum minimumdropout dropoutvoltage voltage during load V higher higher than thanVout Voutin in order device transient response .This pin must always be 1.4V order for for the the device to to regulate properly. Absolute Maximum Ratings Parameter Ratings Symbol DC Supply Voltage VIN Power Dissipation PD Storage Temperature Range TST Operating Juction Temperature Range Unit -0.3 to 12 V Internally Limited TOP o C -65~+150 o C 0~+150 Electrical Characteristics Parameter Reference Voltage Output Voltage Conditions MIN TYP MAX UNIT SU1085-ADJ Io=10mA, TJ =25 , (Vin-Vout )=1.5V 1.225 1.250 1.275 V SU1085-1.5 Io=10mA, TJ =25 , 3V Vin 12V 1.470 1.500 1.530 V SU1085-1.8 Io=10mA, TJ =25 , 3.3V Vin 12V 1.764 1.800 1.836 V SU1085-2.5 Io=10mA, TJ =25 , 4V Vin 12V 2.450 2.500 2.550 V SU1085-3.3 Io=10mA, TJ =25 , 4.8V Vin 12V 3.235 3.300 3.365 V 4.900 5.000 5.100 V - - 0.2 % SU1085-5.0 Io=10mA, TJ =25 , 6.5V Vin 12V SU1085-XXX Io=10mA, Vout+1.5<Vin<12 SU1085-ADJ Vin=3.3V, 0mA<Io<3A, TJ=25 (Note 1,2) - - 1 % SU1085-1.5 Vin=3.0V, 0mA<Io<3A, TJ=25 (Note 1,2) - 12 15 mV SU1085-1.8 Vin=3.3V, 0mA<Io<3A, TJ =25 - 15 18 mV SU1085-2.5 Vin=4.0V, 0mA<Io<3A, TJ=25 (Note 1,2) - 20 25 mV SU1085-3.3 Vin=5.0V, 0mA<Io<3A, TJ=25 (Note 1,2) - 26 33 mV SU1085-5.0 Vin=8.0V, 0mA<Io<3A, TJ=25 (Note 1,2) - 40 50 mV Dropout Voltage (Vin-Vout) SU1085-XXX Io=3A( Vout=1% Vout) - 1.3 1.4 V Current Limit SU1085-XXX Vin-Vout=5V 3.1 - - A Minimum Load Current SU1085-XXX 0 Thermal Regulation TA=25 , 30ms pulse Line Regulator Load Regulation Ripple Rejection Temperature Stability TJ 125 - 5 10 mA 0.008 0.04 %/W 60 70 dB F=120Hz, COUT=25uF, Tantalum, Io=3A SU1085-XXX Vin=Vout+3V Io=10mA Thermal Resistance Junction–to-Ambient (No heat sink ;No air flow) Thermal Resistance Junction-to-Case (Note 1,2) Control Circuitry/Power Transistor - 0.5 - % - 91 - /W - 10 - /W Note 1: See thermal regulation specifications for changes in output voltage due to heating effects. Line and load regulation are measured at a constant junction Temperature by low duty cycle pulse testing. Load regulation is measured at the output lead =1/18” from the package. Note 2: Line and load regulation are guaranteed up to the maximum power dissipation of 15W. Power dissipation is determined by the difference in input and output and the output current. Guaranteed maximum power dissipation will not be available over the full input/output range. Note 3: Quiescent current is defined as the minimum output current required in maintaining regulation. At 12V input/output differential the device is guaranteed to regulate if the output current is greater than 10mA. http://www.SeCoSGmbH.com/ 01-Jun-2002 Rev. A Any changing of specification will not be informed individual Page 2 of 4 SU1085 Elektronische Bauelemente 3A Low Dropout Positive Adjustable or Fixed-Mode Regulator Functional Description Introduction The SU1085 adjustable or fixed-mode Low Dropout (LDO) regulator is a 3 terminal device which can easily be programmed by internal mask change to any voltage within the range of 1.25 to Vin-1.4V. The SU1085 only needs 1.4V differential between Vin and Vout to maintain output regulation, in addition, the output voltage tolerances are also extremely tight and they include the transient response as port of the specification. For example, Intel VRE specification calls for a total of +/-100mV including initial tolerance, load regulation and 0 to 3A load step. The SU1085 is specifically designed to meet the fast current transient needs as well as providing an accurate initial voltage, reducing the overall system cost with the need for fewer output capacitors. Load Regulation Since the SU1085 is only a 3 terminal device, it is not possible to provide true remote sensing of the output voltage at the load. But it can supply good load regulation by internal feedback bypass the external loss such as adjustable mode. Stability The SU1085 requires the use of an output capacitor as part of the frequency compensation in order to make the regulator stable .For most applications a minimum of 10uF aluminum electrolytic capacitor insures both stability and good transient response. Thermal Design The SU1085 incorporates an internal shutdown that protects the device when the junction temperature exceeds the maximum allowable junction temperatures. Although this device can operate with junction temperatures in the range of 150 , it is recommended that the selected heat sink be chosen such that during maximum continuous load operation the junction temperature is kept below the temperature. Layout Consideration The output capacitors must be located as close to the Vout terminal of the device as possible .It is recommended to use a section of a layer of the PC board as a plane to connect the Vout pin to the output capacitors to prevent any high frequency oscillation that may result due to excessive trace inductance. h tp://www.SeCoSGmbH.com/ 01-Jun-2002 Rev. A Any changing of specification will not be informed individual Page 3 of 4 SU1085 Elektronische Bauelemente 3A Low Dropout Positive Adjustable or Fixed-Mode Regulator Typical Performance Characteristics 3A h tp://www.SeCoSGmbH.com/ 01-Jun-2002 Rev. A Any changing of specification will not be informed individual Page 4 of 4