AS2884 8A Low DropOut Voltage Regulator Adjustable & Fixed 3.3V FEATURES APPLICATIONS • Adjustable Output Down to 1.2V or Fixed 3.3V & 5V • Output Current of 8A • Low Dropout Voltage • Extremely Tight Load and Line Regulation • Current & Thermal Limiting • Standard 3-Terminal Low Cost TO-220 • Similar to Industry Standard LT1083/LT1584 • Powering Intel Pentium µP from +5V Supplies • Power PCSupplies • SMPS Post-Regulator • High Efficiency “Green” Computer Systems • High Efficiency Linear Power Supplies • Portable Instrumentation • Constant Current Regulators • Adjustable Power Supplies • Battery Charger PRODUCT DESCRIPTION The AS2884 is a low power 8A Adjustable Voltage Regulator that is very easy to use. It requires only 2 external resistors to set the output voltage. This device is an excellent choice when using Powering Intel Microprocessor to convert from +5V to 3.3V supplies, and as a post regulator for switching supplies applications. The AS2884 features low dropout of a maximum 1.5 volts. The AS2884 offers full protection against over-current faults, reversed input polarity, reversed load insertion, over temperature operation, and positive and negative transient voltage. On-Chip trimming adjusts the reference voltage to 1%. The IQ of this device flows into the load which increases efficiency. The AS2884 is offered in a 3-pin TO-220 package compatible with older 3-terminal regulators. For a 5A low dropout regulator refer to the AS2850 datasheet. ORDERING INFORMATION TO-220 3-PIN AS2884AU X = Output Voltage (i.e. 3.3 for 3.3V, 5.0 for 5.0V etc.) Y = Output Tolerance, A for 1% Blank for 2% Consult with factory for fixed output voltage PIN CONNECTIONS TO-220-3 (U) AS2884 1 2 3 ADJ/GND VOUT VIN Front View Rev. 9/29/00 AS2884 ABSOLUTE MAXIMUM RATINGS Power Dissipation..........................................Internally Limited Lead Temp. (Soldering, 10 Seconds) .............................. 300°C Storage Temperature Range ............................ -65° to +150°C Operating Junction Temperature Range AS2884 Control Section ............................0C° to +125°C AS2884 Power Transistor..........................0C° to +150°C Input Supply Voltage ...................................................... 30V Input to Output Voltage Differential ............................... 30V ELECTRICAL CHARACTERISTICS (Note 1) at IOUT = 10mA, TA = 25°C, unless otherwise specified. Parameter Conditions Typ AS2884A Min Max AS2884-3.3V, 0≤IOUT≤8A, 4.75V≤VIN≤25V 3.3 3.3 3.270 3.240 3.330 3.360 3.230 3.201 3.370 3.399 AS2884-3.3V, 0≤IOUT≤8A, 6.5V≤VIN≤25V 5.0 5.0 4.950 4.900 5.050 5.100 4.900 4.650 5.100 5.150 1.250 1.250 5 0.015 0.05 0.1 0.2 1.1 1.238 1.225 1.262 1.270 10 0.2 0.5 0.3 0.4 1.2 1.238 1.225 1.262 1.270 10 0.2 0.5 0.3 0.4 1.2 8.0 Min AS2884 Max Units 3.3V Version Output Voltage (Note 2) 5.0V Version Output Voltage (Note 2) All Voltage Options Reference Voltage Dropout Voltage 10 mA ≤ IOUT ≤ IFULLLOAD 3.3V≤(VIN - VOUT )≤ VIN MAX – VOUT MAX (VIN- VOUT) = VIN MAX – VOUT MAX 29V ≤VIN - VOUT ≤ VIN MAX – VOUT MAX ILOAD = 10mA 10mA ≤ IOUT ≤ IFULLLOAD (VIN - VOUT)=3V IOUT=IFULLLOAD , ∆VREF=1% Current Limit Mid Load Current Line Regulation Load Regulation V V mA % % V VIN - VOUT=5V 9.5 Long Term Stability TA=125°C, 1000Hrs. 0.3 1 1 % Adjust Pin Current TA=25°C 55 90 90 µA 0.2 5 5 µA 0.003 0.01 0.01 %/W Adjust Pin Current Change Thermal Regulation 30ms pulse Temperature Stability Ripple Rejection Ratio Output Noise, RMS Thermal Resistance Junction-to-Case A 8.0 % 0.5 VIN - VOUT=3V IOUT =3A, COUT = 25µF, CADJ = 25µF, f= 120Hz 10Hz to 10kHz TO-220 Junction to Tab Junction to Ambient 75 60 dB 60 0.003 2.7 0.65 2.7 0.65 % VO °C/W The Bold specifications apply to the full operating temperature range. Note 1: Changes in output voltage due to heating effects are covered under the specification for thermal regulation. Note 2: A 10µF output capacitor is required on AS2884 Rev. 9/29/00 AS2884 TYPICAL CHARACTERISTICS DROPOUT VOLTAGE LOAD REGULATION 0ºC T J 120ºC 1 T J = -55ºC T J =150ºC SHORT CIRCUIT CURRENT (A) INDICATES GUARANTEED TEST POINT -40ºC T J 150ºC T J =25ºC 0.05 0 -0.05 -0.10 -0.15 -0.20 0 0 1 2 3 4 5 6 7 8 9 -50 10 OUTPUT CURRENT (A) 80 7 6 T J =150ºC T J =25ºC 3 2 T J =-55ºC 5 10 15 20 25 50 25 6 -55ºC 4 IFULLLOAD 2 0 75 100 125 150 30 INPUT/OUTPUT DIFFERENTIAL (V) 35 5 10 15 20 25 30 35 INPUT/OUTPUT DIFFERENTIAL (V) TEMPERATURE STABILITY 1.270 70 60 50 40 30 20 1.260 1.250 1.240 10 0 0 0 0 REFERENCE VOLTAGE (V) 90 8 ADJUSTMENT PIN CURRENT (µA) 9 1 150ºC 8 ADJUSTMENT PIN CURRENT 100 4 25ºC INPUT/OUTPUT DIFFERENTIAL (V) 10 5 10 0 -25 MINIMUM OPERATING CURRENT MINIMUM OPERATING CURRENT SHORT CIRCUIT CURRENT 12 0.10 OUTPUT VOLTAGE DEVIATION (%) MINIMUM INPUT/OUTPUT DIFFERENTIAL (V) 2 1.230 -50 -25 0 25 50 75 TEMPERATURE (ºC) 100 125 150 -50 -25 0 25 50 75 100 125 150 TEMPERATURE (ºC) Rev. 9/29/00 AS2884 TYPICAL APPLICATIONS VIN IN AS2884 OUT VIN OUT C1 C1 Fig. 5 Typical Adjustable Regulator Fig. 4 8A Current output Regulator IN AS2884 VCC OUT C2 C1 ADJ R1 Intel PentiumTM 3.45V +5V C2 R1 R2 VOUT = VREF (1 + R2 ) + IADJ R2 R1 LOAD VIN VREF ADJ R1 ADJ VOUT AS2884 IN R2 Powering Intel PentiumTM with AS2884 Pentium Processor is a trademark of Intel Corp. Power PC is a trademark of IBM Corp. Rev. 9/29/00