Data Sheet HIGH SPEED, EXTREMELY LOW NOISE LDO REGULATOR AP2121 General Description Features The AP2121 series are positive voltage regulator ICs Low Dropout Voltage at I =100mA: 150mV OUT fabricated by CMOS process. Each of these ICs con- Typical (Except 1.2V, 1.3V and 1.5V Versions) sists of a voltage reference, an error amplifier, a resis- Low Standby Current: 0.1A Typical tor network for setting output voltage, a current limit Low Quiescent Current: 25A Typical circuit for current protection and a chip-enable circuit High Ripple Rejection: 70dB Typicalf=1kHz (5-pin products only). Output Current: More Than 200mA (300mA Limit) The AP2121 series feature high supply voltage ripple Extremely Low Noise: 30Vrms (10Hz to rejection, low dropout voltage, low noise, high output 100kHz) voltage accuracy, and low current consumption which make them ideal for use in various battery-powered Excellent Line Regulation: 4mV Typical devices. Excellent Load Regulation: 12mV Typical High Output Voltage Accuracy: 2% The AP2121 series have 1.2V, 1.3V, 1.5V, 1.8V, 2.5V, Excellent Line Transient Response and Load 2.8V, 2.85V, 3.0V, 3.2V and 3.3V versions. Transient Response Compatible with Low ESR Ceramic Capacitor (as The AP2121 are available in standard SOT-23-3, SOT- Low as 1F) 23-5 and CSP-4 packages. Applications Mobile Phones, Cordless Phones Wireless Communication Equipment Portable Games Cameras, Video Recorders Sub-board Power Supplies for Telecom Equip- ment Battery Powered Equipment SOT-23-3 SOT-23-5 CSP-4 Figure 1. Package Types of AP2121 Dec. 2012 Rev. 2. 6 BCD Semiconductor Manufacturing Limited 1 Data Sheet HIGH SPEED, EXTREMELY LOW NOISE LDO REGULATOR AP2121 Pin Configuration N Package K Package (SOT-23-3) (SOT-23-5) V IN 3 V 1 5 V IN OUT GND 2 NC CE34 1 2 V GND OUT J4/J4A Package J4C/J4B Package (CSP-4 (P 0.5)/CSP-4 (P 0.4)) (CSP-4 (P 0.5)/CSP-4 (P 0.4)) Pin 1 Mark Pin 1 Mark CE V IN V V IN OUT A1 A2 A1 A2 B1 B2 B1 B2 GND V OUT CE GND Figure 2. Pin Configuration of AP2121 (Top View) Pin Description Pin Number Pin Name Function SOT-23-3 SOT-23-5 CSP-4 CSP-4 (J4/J4A) (J4C/J4B) 3 1 A2 A1 V Input voltage IN 1 2 B1 B2 GND Ground 3 A1 B1 CE Active high enable input pin. Logic high=enable, logic low=shutdown 4 NC No connection 25 B2 A2 V Regulated output voltage OUT Dec. 2012 Rev. 2. 6 BCD Semiconductor Manufacturing Limited 2