AMS2566 Features General Description Wide 3.6V to 25V Input Voltage Range Output Adjustable from 0.8V to 24V Maximum Duty Cycle 100% Minimum Drop Out 0.6V Fixed 360KHz Switching Frequency 5A Constant Output Current Capability Internal Optimize Power MOSFET High efficiency up to 85~90% The AMS2566 is a 360 KHz fixed frequency PWM buck (step-down) DC/DC converter, capable of driving a 5A load with high efficiency, low ripple and excellent line and load regulation. Requiring a minimum number of external components, the regulator is simple to use and include internal frequency compensation and a fixed-frequency oscillator. Excellent line and load regulation TTL shutdown capability EN pin with hysteresis function Built in thermal shutdown function Built in current limit function Built in output short protection function Package in TO-263/TO252 and TO220 Applications LCD Monitor and LCD TV TO220 can supply 5A continues TO263 can supply 5A , TO252 can supply 4A ADSL Modem Telecom / Networking Equipment The PWM control circuit is able to adjust the duty ratio linearly from 0 to 100%. An enable function, an over current protection function is built inside. When short protection function happens, the operation frequency will be reduced from 360KHz to 70KHz. An internal compensation block is built in to minimize external component count. 1 Advanced Monolithic Systems http://www.ams-semitech.com AMS2566 Pin Configurations for TO263/TO220/TO252 : Important Note : Pin3 SW is shorted to Tab (heat -sink is not ground) Table 1 Pin Description Pin Number Pin Name 1 GND 2 FB 3 SW 4 EN 5 VIN Description Ground Pin. Care must be taken in layout. This pin should be placed outside of the Schottky Diode to output capacitor ground path to prevent switching current spikes from inducing voltage noise into AMS2566. Feedback Pin (FB). Through an external resistor divider network, FB senses the output voltage and regulates it. The feedback threshold voltage is 0.8V. Power Switch Output Pin (SW). SW is the switch node that supplies power to the output. Enable Pin. Drive EN pin high to turn on the device, drive it low to turn it off. Floating is default high. Supply Voltage Input AMS2566 operates from a 3.6V to 25V DC voltage. Bypass Vin to GND with a suitably large capacitor to eliminate noise on the input. 2 Advanced Monolithic Systems http://www.ams-semitech.com AMS2566 Function Block Figure3. Function Block Diagram of AMS2566 Typical Application Circuit 3 Advanced Monolithic Systems http://www.ams-semitech.com AMS2566 Ordering Information Package Temperature Range FACT Lead Free TO263-5/TO252-5 Part Number Lead Free AMS2566-XX AMS2566L-XX voltage XX TO220-5 (two lines, two pins back three front) XLSEMI Pb-free products, as designated with “E1” suffix in the par number, are RoHS compliant. Absolute Maximum Ratings（Note1） Parameter Symbol Vin VFB VEN VOutput PD Value -0.3 to 27 -0.3 to Vin -0.3 to Vin -0.3 to Vin Internally limited Unit V V V V mW Input Voltage Feedback Pin Voltage EN Pin Voltage Output Switch Pin Voltage Power Dissipation Thermal Resistance (TO263) (Junction to Ambient, No Heatsink, Free Air) Operating Junction Temperature Storage Temperature Lead Temperature (Soldering, 10 sec) ESD (HBM) RJA 50 ºC/W TJ TSTG TLEAD -40 to 125 -65 to 150 260 2000 ºC ºC ºC V Note1: Stresses greater than those listed under Maximum Ratings may cause permanent damage to the device. This is a stress rating only and functional operation of the device at these or any other conditions above those indicated in the operation is not implied. Exposure to absolute maximum rating conditions for extended periods may affect reliability. 4 Advanced Monolithic Systems http://www.ams-semitech.com AMS2566 Electrical Characteristics Ta = 25℃;unless otherwise specified. Symbol Parameter Test Condition Min. Typ. Max. Unit 0.776 0.8 0.824 V - 89 - % System parameters test circuit figure4 Feedback Voltage VFB Efficiency ŋ Vin = 5V to 25V, Vout=5V Iload=0.5A to 5A Vin=12V ,Vout=5V Iout=4.0A Electrical Characteristics (DC Parameters) Vin = 12V, GND=0V, Vin & GND parallel connect a 220uf/50V capacitor; Iout=500mA, Ta = 25℃; the others floating unless otherwise specified. Parameters Symbol Test Condition Min. Typ. 3.6 Max. Unit 25 V Input operation voltage Vin Shutdown Supply Current ISTBY VEN=0V 60 200 uA Quiescent Supply Current Iq VEN =2V, VFB =Vin 3 5 mA 360 402 Oscillator Frequency Fosc Switch Current Limit IL VFB =0 8 A VEN High (Regulator ON) Low (Regulator OFF) 1.4 0.8 V IH VEN =2V (ON) 1 15 uA IL VEN =0V (OFF) 1 15 uA DMAX VFB=0V 100 EN Pin Threshold EN Pin Input Leakage Current Max. Duty Cycle 298 5 Advanced Monolithic Systems http://www.ams-semitech.com Khz % AMS2566 Test Circuit and Layout guidelines Figure5. Standard Test Circuits and Layout Guides Select R1 to be approximately 2K, use a 1% resistor for best stability. C1 and CFF are optional; in order to increase stability and reduce the input power line noise, CIN and C1 must be placed near to PIN1 and PIN3; For output voltages greater than approximately 10V, an additional capacitor CFF is required. The compensation capacitor is typically between 100 pf and 33 nf, and is wired in parallel with the output voltage setting resistor, R2. It provides additional stability for high output voltage, low input-output voltages, and/or very low ESR output capacitors, such as solid tantalum capacitors. CFF=1/(31*1000*R2); This capacitor type can be ceramic, plastic, silver mica, etc. (Because of the unstable characteristics of ceramic capacitors made with Z5U material, they are not recommended.) 6 Advanced Monolithic Systems http://www.ams-semitech.com AMS2566 Schottky Diode Selection Table Current 1A 3A Surface Through VR (The same as system maximum input voltage) Mount Hole 20V 30V 40V 50V 1N5817 1N5818 1N5819 √ √ 1N5820 1N5821 1N5822 √ MBR320 MBR330 MBR340 MBR350 MBR360 SK32 SK33 SK34 SK36 30WQ03 30WQ04 30WQ05 31DQ03 31DQ04 31DQ05 SR305 SR306 √ √ √ 5A √ 60V SK35 √ SR302 SR303 SR304 √ 1N5823 1N5824 1N5825 √ SR502 SR503 SR504 SR505 SR506 √ SB520 SB530 SB540 SB550 SB560 50WQ03 50WQ04 50WQ05 7 Advanced Monolithic Systems http://www.ams-semitech.com AMS2566 Typical System Application for 24V ~ 12V/3A Version Figure6. AMS2566 System Parameters Test Circuit (24V ~ 12V/3A) Typical System Application for 24V ~ 5V/5A Figure7. AMS2566 System Parameters Test Circuit (24V ~ 5V/5A) 8 Advanced Monolithic Systems http://www.ams-semitech.com AMS2566 Package information: (1) TO263-5L (2) TO220-5 is 3pins front and 2 back same as BM2596-L so , it will not be described here . 9 Advanced Monolithic Systems http://www.ams-semitech.com AMS2566 (3) Package Information TO252-5L 10 Advanced Monolithic Systems http://www.ams-semitech.com