Data Sheet 300mA HIGH SPEED, EXTREMELY LOW NOISE CMOS LDO REGULATOR AP2128 General Description Features The AP2128 series are positive voltage regulator ICs Wide Operating Voltage: 2.5V to 6V fabricated by CMOS process. The AP2128 provides Low Dropout Voltage:170mV 300mA for two kinds of output voltage operation modes for V =3.3V, 140mV 300mA for V =5.2V OUT OUT setting the output voltage. Fixed output voltage mode High Output Voltage Accuracy: 2% senses the output voltage on V , adjustable output OUT High Ripple Rejection: voltage mode needs two resistors as a voltage divider. 68dB f=1kHz, 54dB f=10kHz Low Standby Current: 0.1 A The AP2128 series have features of low dropout Low Quiescent Current: 60 A Typical voltage, low noise, high output voltage accuracy, and Low Output Noise: 60 Vrms V =0.8V low current consumption which make them ideal for OUT use in various battery-powered devices. Short Current Limit: 50mA Over Temperature Protection AP2128 have 1.0V, 1.2V, 1.5V, 1.8V, 2.5V, 2.8V, 3.0V, Compatible with Low ESR Ceramic Capacitor: 3.3V, 3.9V, 4.2V, 4.75V, 5.2V fixed voltage versions 1 F for C and C IN OUT and 0.8V to 5.5V adjustable voltage version. Excellent Line/Load Regulation Soft Start Time: 50 s AP2128 series are available in SOT-23-5 package. Auto Discharge Resistance: R =60 DS(ON) Applications Datacom Notebook Computers Mother Board SOT-23-5 Figure 1. Package Type of AP2128 Sept. 2010 Rev. 2.0 BCD Semiconductor Manufacturing Limited 1 Data Sheet 300mA HIGH SPEED, EXTREMELY LOW NOISE CMOS LDO REGULATOR AP2128 Pin Configuration K Package (SOT-23-5) Shutdown ADJ/NC 1 5 GND 2 V V 34 IN OUT Figure 2. Pin Configuration of AP2128 (Top View) Functional Block Diagram 1 SHUTDOWN Shutdown 3 VIN and Logic Control V REF MOS Driver 4 VOUT Current Limint And Thermal Protection 2 GND Fixed Version Sept. 2010 Rev. 2.0 BCD Semiconductor Manufacturing Limited 2