ACE555

                                                                                           ACE555                                               Technology Description 400mA LDO Dropout Voltage Regulator ACE555 is a series of low dropout three terminal regulators with a dropout of 1.22V at 400mA load current. Other than a fixed version（Vout＝1.8V,2.5V,2.85V,3.3V,5V）, ACE555 has an adjustable version, which can provide an output voltage from 1.25 to 13.8V with only two external resistors. ACE555 offers thermal shut down and current limit functions, to assure the stability of chip and power system. And it uses trimming technique to guarantee output voltage accuracy within ±2％. ACE555 is available in SOT-89-3 power Package. Lead free package is also available on command. Features • • • • • • • • • • Other than a fixed version and an adjustable version, output value can be customized on command. Maximum output current is 400mA Output voltage accuracy is within ±1％ Range of operation input voltage: Max 18V Line regulation: 0.2％ Load regulation: 0.4％ Environment Temperature: -50℃~140℃ Application Power Management for Computer Mother Board, Graphic Card LCD Monitor and LCD TV DVD Decode Board Absolute Maximum Ratings Parameter Input voltage Power Dissipation SOT-89-3 Junction temperature Environment Temperature Storage temperature TJ TA TS Symbol VIN Max 18 0.5 150 140 65 to 150 Unit V W O O C C O C VER 1.2 1                                                                                             ACE555                                               Technology Packaging Type SOT-89-3 400mA LDO Dropout Voltage Regulator Pin SOT-89-3(A) SOT-89-3(B) SOT-89-3(C) VOUT 1 3 2 GND 2 1 1 VIN 3 2 3 1 2 3 Ordering information Selection Guide ACE555 XX XXX + H Halogen - free Pb - free AMA: SOT-89-3 AMB: SOT-89-3 AMC: SOT-89-3 Output Voltage : 1.8V / 2.5V ….. 5.0V Block Diagram VER 1.2 2                                                                                            ACE555                                               Technology Recommended Work Conditions Item Min Nom Max Unit Input Voltage Range 18 V O Ambient Temperature -50 140 C 400mA LDO Dropout Voltage Regulator Electrical Characteristics Symbol Prameter Condition ACE555-1.8V ACE555-2.5V ACE555-2.85V ACE555-3.3V ACE555-5.0V Vin=5V～15V ACE555-5.0V (Vin=7V~15V) IL＝0～400mA ΔVout, ΔVref,=1%， Iout=400mA Vin-Vout=2V, Tj=25℃ Min Typical Max Units 1.764 1.80 1.836 V 2.45 2.5 2.55 V 2.793 2.85 2.907 V 3.234 3.3 3.366 V 4.9 5 5.1 V 0.2 0.4 % 0.2 0.2 1.22 600 4 8 0.5 0.4 0.4 1.3 % % V mA mA % Vout Output Voltage ΔVout ΔVout Dropout Voltage Current Limit Iq ΔVout/ ΔT∙Vout Line Regulation（note1） Load Regulatiion（note1,2） Input-Output Voltage Differentia（note3） Max Load Current Quiescent Current Temperature Stability Note：1.The Parameters of Line Regulation and Load Regulation in Table1 are tested under constant junction temperature. The Curve of Load Regulation vs. Temperature is shown in typical parameter curve that follows. 2.When Iout varies between 0~400mA,Vin-Vout varies between 1.5V~12V under constant junction temperature，the parameter is satisfied the criterion in table. If temperature varies between -50℃≤TA≤140℃，it needs output current to be larger than 10mA to satisfy the criterion. 3.Dropout Voltage is specified over the full output current range of the device, and it is tested under following testing conditions: First step is to find out the Vout value (Vout1) when Vin1=Vout+1.5V, second step is to decrease Vin(Vin2) until Vout value is equal to 99%*Vout1(Vout2). Vdropout=Vin2-Vout2. 4.Minimum Load Current is defined as the minimum output current required to maintain regulation. When 1.5V≦Vin-Vout≦12V，the device is guaranteed to regulate if the output current is greater than 10mA. VER 1.2 3                                                                                            ACE555                                               Technology Detailed Description 400mA LDO Dropout Voltage Regulator ACE555 is a series of low dropout voltage, three terminal regulators. Its application circuit is very simple: the fixed version only needs two capacitors and the adjustable version only needs two resistors and two capacitors to work. It is composed of some modules including start-up circuit, bias circuit, bandgap, thermal shutdown, current limit, power transistors and its driver circuit and so on. The thermal shut down and current limit modules can assure chip and its application system working safety when the environment temperature is larger than 140℃ or output current is larger than 600mA. The bandgap module provides stable reference voltage, whose temperature coefficient is compensated by careful design considerations. The temperature coefficient is under 100ppm/℃. And the accuracy of output voltage is guaranteed by trimming technique, Typical Application ACE555 has an adjustable version and five fixed versions, Chart1 is its typical application. ACE555 Vin + Cin 10uF Vin GND + 22uF Cout Vout Vout Application Hints 1.Recommend using 10uF tan capacitor as bypass capacitor(C1) for all application circuit. 2.Recommend using 22uF tan capacitor to assure circuit stability. 3.Using a bypass capacitor(CAdj) between the adjust terminal and ground can improve ripple rejection, This bypass capacitor prevents ripple from being amplified as the output voltage is increased.The impedance of CAdj should be less than the resistor’s(R1) which is between output and adjust pins to prevent ripple from being amplified at any ripple frequency. As R1 is normally in the range of 200Ω~350 Ω,the value of CAdj should satisfy this equation:2*Fripple*CAdj