AMS1318 ■ General Description ■ Applications efficiency Cellular and Smart Phones synchronous-rectification type buck regulator using a PDAs constant frequency, current mode architecture. The device MP3/MP4 Player is available in an adjustable version and fixed output Digital Still and Video Cameras voltages of 1.8V and 3.3V. Automatic PWM/PFM mode Microprocessors and DSP Core Supplies operation increases efficiency and decreases output Portable Instruments AMS1318 series is a group of high voltage ripple at light loads, further extending battery life. ■ Package Switching frequency is internally set at 1.4MHz, allowing the use of small surface mount inductors and capacitors. SOT-23-5L 100% duty cycle provides low dropout operation. 5 ■ Features 4 High Efficiency: 92％ Input Voltage Range: 2.0 ~ 6.0V Output Current: 800mA CE 1 GND LX 2 3 (Top View) Shutdown Current: <1uA Oscillation Frequency: 1.4MHz ■ Typical Application Circuit ■ Ordering Information AMS1318 ①②③④⑤ Designator Symbol Description ① 1 1 3 4 Output Voltage: 1.2V、1.8V、3.3V、4.2V ② 2 8 3 2 Adjustable version: ① ② fixed as 00 ③ F Oscillation Frequency 1.4MHz ④ M Package Types: SOT-23-5 S Embossed Tape :Standard Feed R Embossed Tape :Reverse Feed ⑤ VIN FB/VOUT 1 Advanced Monolithic Systems http://www.ams-semitech.com AMS1318 5 4 VIN FB/VOUT CE GND LX 1 2 3 (Top View) Pin Number Pin Name Function 1 CE Chip Enable Pin 2 GND Common Ground 3 LX Switching Output 4 VIN Power Input 5 FB/VOUT Feedback/Output Voltage Pin ■ Marking Rule SOT-23-5L 5 4 ① ② ③ ④ ⑤ ⑥ 1234 1 2 3 SOT-23-5L 1 Represents the product name Symbol Product Name AMS1318 ◆◆◆◆◆ 3 2 3 Represents the product classification Symbol 2 3 4 Feedback mode Working mode Number Description 0 Adjustable 2 1.2V 8 1.8V 3 3.3V 4 4.2V P PWM/PFM B PWM/BURST Represents the technological processes change 0-9，A-Z; 0-9，A-Z mirror writing，repeated（G，I，J，O，Q，W exception） 30BC Eg: Represents AMS1318, external feedback mode, working mode is PWM/PFM Note: ①②③④⑤⑥ represent code point, represent production lot number. 2 Advanced Monolithic Systems http://www.ams-semitech.com AMS1318 ■ Function Block Diagram ■ Absolute Maximum Ratings Parameter Symbol Ratings Units Input Supply Voltage VIN -0.3～6.5 VOUT -0.3～6.5 VLX -0.3～VIN + 0.3 CE Voltage VCE -0.3～VIN + 0.3 V Peak LX Current ILX ±1000 mA PD 250 mW Operating Temperature Range Topr -40～＋85 Storage Temperature Range Tstg -55～＋125 V Output Voltage Power Dissipation SOT-23-5L ℃ Note: Absolute Maximum Ratings are those values beyond which the life of a device may be impaired. 3 Advanced Monolithic Systems http://www.ams-semitech.com AMS1318 ■ Electrical Characteristics VIN=3.6V ,CIN=4.7uF ,CL=10uF ,L=2.2uH Parameter (Ta=25℃, unless otherwise noted) Symbol Cinditons MIN TYP MAX Feedback Voltage VFB - 0.59 0.6 0.61 Input Voltage Range VIN 2 - 6 Test Units Circuits V Load regulation VOUT Line regulation △VOUT ILMAX=600mA 0.5 % IL=300mA 0.45 % － Efficiency EFFI VIN=2.7V；IL=100mA CE ”Low” voltage VCEL - CE ”High” voltage VCEH - Stand-by Current ISTB VCE=0V、VIN=3.6V 0 Quiescent Current IDD VFB=0.6V*0.9 Output Current Limit ILIM - PFM switching point IL FOSC Maximum Duty Circle MAXDTY % 1.8 V 1.4 V - 1 uA － 200 - uA - 1200 - mA 3 VIN=3.6V、VOUT=1.8V Oscillation Frequency － 92 1 150 mA - 1.4 - MHz 100 - - % 2 - ■ Test Circuits Parameters：LX=2.2uH, C1=4.7uF, C2=22pF, C3=10uF. Vout=0.6Vx(1+R1/R2) According to the required output voltage regulate R1, R2, so V FB = 0.6V. Circuit 1 Circuit 2 FOSC L VIN LX VIN LX R1 R1 C2 Vin C1 CE C2 Iload FB Vin C3 GND C1 CE FB R2 Circuit3 IIN VIN Vin CE C1 C3 GND R2 FB GND 4 Advanced Monolithic Systems http://www.ams-semitech.com AMS1318 ■ Typical Performance Characteristics Output voltage vs output current Input voltage vs output voltage Output voltage vs Temperature 1.8V Efficiency vs output current 3.3V Efficiency vs output current 5 Advanced Monolithic Systems http://www.ams-semitech.com AMS1318 ■ Package Information SOT-23-5L 6 Advanced Monolithic Systems http://www.ams-semitech.com