AMS3121 2A Fast Transient Linear Regulator General Description Features The AMS3121 is a high performance linear regulator with very low dropout voltage and excellent transient response. It is designed to operate with wide input voltage range of 1.5 – 7Volts making it ideal for two step conversion while maintaining high efficiency for many power sensitive applications. The device is capable of supplying 2A of output current with a typical dropout voltage of 550mV at 2A. The product is only available in a fixed output voltage option. The product includes complete short-circuit and thermal protection. The combination of these two internal protection circuits gives the device a comprehensive safety system to safe guard against extreme adverse operating conditions. The AMS3121 is available in both 3-pin TO-220 and TO-263 packages, and it is rated for -40°C to +125°C temperature range. • • • • • • • • • • • • • VIN range: 1.5 – 7V Fixed output voltage as low as 0.6V 2A maximum output current 550mV typical dropout voltage at 2A Low self noise 125µA typical supply current PSRR >40dB at 10KHz Stable with Electrolytic, Tantalum or Ceramic capacitors Current Limit protection Over-Temperature Shutdown -40 to +125°C temperature range Available in 3-pin TO-220 and TO-263 surface mount packages RoHS & WEEE compliant Applications • • • • • • • Set-top Box DVD, Blue-ray DVD writers LCD TVs and LCD monitors Battery Powered Equipment Infotainment Wireless & RF: applications High Efficiency “Green” Laptops & notebook Typical Application 02/11/2010 www.advanced-monolithic.com 1 Phone (925) 443-0722 Fax (925) 443-0723 AMS3121 2A Fast Transient Linear Regulator Pin Description (TO-220 and TO-263 3-Pin Package) Pin # Symbol Description 1 VIN 2 GND Ground 3 VOUT Output Voltage Input supply Voltage. It powers the internal control circuitry and the internal power switch. Bypass VIN with at ceramic capacitor from this pin to ground. Pin Configuration 02/11/2010 www.advanced-monolithic.com 2 Phone (925) 443-0722 Fax (925) 443-0723 AMS3121 2A Fast Transient Linear Regulator Absolute Maximum Ratings (1) Recommended Operating Conditions (2) Maximum Input Supply Voltage (VIN)………....…...… -0.3V to 15V Storage Temperature Range……………................ -65⁰C to 150⁰C Lead Temperature…………………..………….……….…..… 260⁰C Junction Temperature………...…………………..……..……..125⁰C Input Voltage………………………….………….……….. 1.5V to 7V Ambient Operating Temperature…….….………… -40⁰C to 125⁰C Thermal Information TO-220 3-pin θJA .. …………...…………….………….…...50⁰C/W (3) TO-263 3-pin θJA ………………………….………………30⁰C/W Electrical Characteristics Unless otherwise noted: VIN=3.3V; VOUT=1.8V; CIN=10 µF; COUT=22µF; -40⁰C≤TA=TJ≤85⁰C; TJ(Max.)= 125°C; Typical values are TA= 25°C Parameter Output Voltage Accuracy Maximum Output Current Load Regulation Line Regulation Supply Current Current Limit Dropout Voltage Output Noise Voltage Thermal Shutdown Thermal Shutdown Hysteresis Conditions VOUT ISUP ILIM VDO en Min. Typ. -3 2 IOUT_Max ΔVOUT/ΔVIN PSRR Notes: 1. 2. 3. Symbol Max. Units 3 % A % % mA A IOUT= 0 – 2A VIN=3.0 – 7.0V; IOUT=100mA VIN=3.3V, Io=0A 0.1 0.2 0.2 2.5 IOUT=0.1A; VOUT=95% of VOUT(NOM) 85 IOUT=0.5A; VOUT=95% of VOUT(NOM) 180 IOUT=1A; VOUT=95% of VOUT(NOM) 275 IOUT=2A; VOUT=95% of VOUT(NOM) 550 F=10KHz Io=20mA 40 dB BW= 100Hz –100 KHz COUT = 10µF IOUT = 500mA 125 µV(rms) 145 15 °C °C TSD TSD_HYS 0.5 mV Stresses above those listed in Absolute Maximum Ratings may cause permanent damage to the device. Measured on approximately 1” square of 1 oz. copper. With package soldering to 0.5in2 copper area over backside ground plane or internal power plane θJA can vary from 20°C/W to >40°C/W depending on mounting technique. The thermal resistance Junction to Case is 45⁰C/W. Total power dissipation for the switching regulator and the LDO should be taken in consideration when calculating the output current capability of each regulator 02/11/2010 www.advanced-monolithic.com 3 Phone (925) 443-0722 Fax (925) 443-0723 A AMS3 3121 2A Fas st Transien nt Linear Regulator Ground Current vs. Output Current C VOUT=2.5 5V, VIN=3.3V 70 60 50 40 30 20 10 0 Outp put Voltage Temperature T Variation Output Voltage (V) Ground Current ((mA)) Ty ypical Perfo ormance Characteris C stics (TA = 25°C 2 unless otherwise o sp pecified) 0.0 0.4 0.8 8 1.2 1.6 1.808 1.806 1.804 1.802 1.800 1.798 1.796 1.794 1.792 2.0 0 --25 0 2 25 50 75 5 100 Ambient Temperature T (ºC) -50 0.2 1.0 0.1 0.0 -0.1 0.8 2A 0.6 0.4 0.2 -0.2 1A 0.0 3 4 5 6 Input Voltage (V) 7 Load Regulation 0.2 --25 0 2 25 50 75 5 100 Ambient Temperature T e (°C) -50 125 5 Dro opout Voltag ge vs. Outpu ut Current 0.6 0.5 0.1 Voltage (V) Output Voltage Change (%) Dropout Volta age vs. Temp perature Line Regullation VOUT = 2.5V Voltage (V) Output p Voltage g Error (%) ( ) Output Cu urrent (A) 125 5 0.0 -0.1 0.4 0.3 0.2 VOUT = 2.5V O 0.1 -0.2 0.0 0.0 02/11/2010 0 0.1 1.0 Outputt Current (A) 10.0 0 0 0.5 1 1.5 Output Current C (A) www.ad dvanced-mono olithic.com 4 Phone (925)) 443-0722 Fax (925)) 443-0723 2 AMS3121 2A Fast Transient Linear Regulator Typical Performance Characteristics (TA = 25°C unless otherwise specified) Load Transient 100mA to 1.5A, VOUT=1.8V,VIN=3.3V, CIN=COUT=22µF VIN Start-Up 0-550mA, VOUT=1.8V,VIN=3.3V, CIN=COUT=22µF V OUT 50mVac /div V OUT 1V /div ISW OUT 500mA /div VIN 1V/div 10 µsec/div 02/11/2010 100 µsec/div www.advanced-monolithic.com 5 Phone (925) 443-0722 Fax (925) 443-0723 AMS3121 2A Fast Transient Linear Regulator Functional Block Diagram VIN VOUT Current Limit Enable R1 - Error Amp + R2 Over Temperature VREF= 0.6V GND Figure 1: Block Diagram of AMS 3121 3-Pin TO-220 (T) / TO-263 (M) 02/11/2010 www.advanced-monolithic.com 6 Phone (925) 443-0722 Fax (925) 443-0723 AMS3121 2A Fast Transient Linear Regulator Device Summary The AMS3121 is a high voltage low drop out linear regulator with a current capability of up to 2A. The LDO has an input voltage range of 1.5V to 7V with an output voltage as low as 0.6V and is stable with a wide range of ceramic, tantalum, and electrolytic output capacitors. Fault Protection Short circuit and over-temperature shutdown disable the converter and LDO in the event of an overload condition. Overtemp shutdown disables the device when the junction temperature exceeds 145 ºC. The output current is internally limited to 2.5A. Input Capacitor An input bypass capacitor ranging from 1µF to 10µF is required. The capacitor should be placed as close as possible to the device and not be placed more than 1 inch from the LDO. Output Capacitor The output capacitor requirements range from the minimum value required to guarantee stability to larger values required to meet the extreme transient response requirements. Values range from 10 to 22µF X5R ceramic capacitors. Due to the extreme voltage coefficient of X5R ceramic capacitors, the voltage rating should be at least double the maximum applied voltage. 02/11/2010 PCB Layout The following guidelines should be followed to insure proper layout. 1. VIN Capacitor. A low ESR ceramic bypass capacitor must be placed as close to the IC as possible. 2. Ground. 3. For good thermal performance vias are required to couple the exposed tab of both TO-220 and TO-263 packages to the PCB ground plane. The via diameter should be 0.3mm to 0.33mm positioned on a 1.2mm grid. Output Power and Thermal Limits The AMS3121 junction temperature and current capability depends on the internal dissipation and the junction to case thermal resistance of the TO-220 and TO-263 exposed tab packages. Additionally, the tab paddle and PCB temperature will be elevated due to the total losses of the LDO and of other circuits mounted to the PCB. Tjmax=Pd·θjc+Tpcb+Tamb The internal losses contribute to the junction temperature rise above the paddle and PCB temperature. www.advanced-monolithic.com 7 Phone (925) 443-0722 Fax (925) 443-0723 AMS3121 2A Fast Transient Linear Regulator Figure 2: AMS3121 TO-263 3-Pin Option Evaluation Board - Top Side Figure 3: AMS3121 TO-263 3-Pin Option Evaluation Board - Bottom Side C3 470uF *1 C4 22uF *2 GND VOUT 3 Vin 2 1 VIN U1 AMS3121 C1 22uF Vout C2 22uF C6 22uF *2 C5 470uF *1 gnd gnd C1, C2 22uF X5R 1210 10V Ceramic Capaci tor *1. Optional Electrolyti c Capaci tor in place of Ceramic Capacitor *2. Optional Tantalum Capacitor in place of Ceramic Capacitor Figure 4: AMS3121 Evaluation Board Schematic Table 1: Evaluation Board Bill of Materials Manufacturer Manufacturer Part Number Component Value C1,C2 C3,C5,C4,C6 U1 22µF, 10V, X5R, 0805, Ceramic Optional Low Drop Out Linear Regulator 02/11/2010 Taiyo Yuden LMK212BJ226MG-T AMS AMS3131 www.advanced-monolithic.com 8 Phone (925) 443-0722 Fax (925) 443-0723 AMS3121 2A Fast Transient Linear Regulator Ordering Information Device AMS3121T-XX(1)(2)(3) TO-220 3-Pin Package AMS3121M-XX(1)(2)(3) TO-263 3-Pin Notes: 1. Available in tape and reel only. A reel contains 2,500 devices. 2. Available in lead-free package only. Device is fully WEEE and RoHS compliant 3. Need to specify output voltage option ( ) Outline Drawing and Landing Pattern Package dimensions are inches (millimeters) unless otherwise noted. 0.060 (1.524) TYP 0.390-0.415 (9.906 -10.541 ) 0.165-0.180 (4.191-4.572) 0.004 +0.008 -0.004 ( 0.102 +0.203 -0.102 0.330 -0.370 (8.382-9.398 ) 0.199 -0.218 (5.05-5.54) 0.090-0.110 (2.286 -2.794) 02/11/2010 0.032 (0.81) TYP 0.045-0.055 (1.143-1.397) 0.108 (2.74) TYP 0.013-0.023 (0.330 -0.584) www.advanced-monolithic.com 9 ) 0.095-0.115 (2.413-2.921) 0.90-0.110 (2.29-2.79) M (DD3) AMS DRW # 042191R1 Phone (925) 443-0722 Fax (925) 443-0723