AMS3109 Micropower 700mA Low Noise Fast Transient Response LDO General Description Features The AMS3109 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 – 12Volts making it ideal for two step conversion while maintaining high efficiency for many power sensitive applications. The device is capable of supplying 700mA of output current with a typical dropout voltage of 550mV. The product is available in adjustable output voltage. The linear regulator has been optimized for noise sensitive applications. The device includes an Enable pin for electrical on/off of the regulator. Forcing the Enable pin to logic low shuts down the LDO and reduces the supply current below 1µA. 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 AMS3109 is available in a thermally enhanced SOIC-8 EDP package, and it is rated for -40°C to +125°C temperature range. • • • • • • • • • • • • • • • VIN range: 1.5 – 12V Adjustable output voltage as low as 0.6V 700mA maximum output current 550mV typical dropout voltage at 700mA Low self noise Enable (EN) pin for LDO on/off 120µA typical supply current ByPass (CBYP) Pin for low PSRR and output noise PSRR > 40dB at 10KHz Stable with Electrolytic, Tantalum or Ceramic capacitors Current Limit protection Over-Temperature Shutdown -40 to +125°C temperature range Thermally enhanced SOIC-8 exposed paddle package RoHS & WEEE compliant Applications • • • • • • • • ASIC Power Supplies In: ¾ Set-top Boxes, Desktops, Notebooks ¾ Graphic Cards, Printers and Copiers DVD, Blue-Ray DVD writers LCD TVs and LCD monitors Infotainment Wireless & RF: applications DSP and FPGA Power Supplies Medical Instrumentation SMPS Post-Regulator Typical Application 02/11/2010 www.advanced-monolithic.com 1 Phone (925) 443-0722 Fax (925) 443-0723 AMS3109 Micropower 700mA Low Noise Fast Transient Response LDO Pin Description (SOIC-8 EDP package) Pin # Symbol Description 1 BYP Reference Bypass pin. Connect an external capacitor from CBYP to ground to bypass the noise generated by the internal bandgap. This improves power supply rejection ratio and output noise. 2 NC No Connection 3 GND 4 VIN 5 VOUT Output Voltage 6 ADJ Provides feedback to error amplifier from the resistive divider that sets the output voltage. 7 NC No Connection 8 EN Enable pin. It controls the electrical on/off of the device. When connected to logic low, the device shuts off and consumes less than1µA of current. Logic high will resume normal operation. 9 GND Ground 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. Expose pad. Connected to PCB ground plane for good thermal dissipation. Pin Configuration SOIC-8EDP (Top View) 02/11/2010 www.advanced-monolithic.com 2 Phone (925) 443-0722 Fax (925) 443-0723 AMS3109 Micropower 700mA Low Noise Fast Transient Response LDO Absolute Maximum Ratings (1) Recommended Operating Conditions (2) Maximum Input Supply Voltage (VIN)………....……..… -0.3V to 15V Enable Voltage (EN)……………..…..………….……… -0.3V to 15V Adjustable Voltage (ADJ).……...………………………… -0.3V to 3V ByPass Voltage (BYP)…………..…..…………………… -0.3V to 3V Storage Temperature Range……………................. -65⁰C to 150⁰C Lead Temperature…………………..…………...……………… 260⁰C Junction Temperature………...………………..…..…………… 125⁰C Input Voltage……………………………..……….……….. 1.5V to 12V Ambient Operating Temperature…………….……… -40⁰C to 125⁰C Thermal Information 8L SOIC EP θJA (3) ……………………………….……….…...45⁰C/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 Symbol Conditions Min. Output Voltage Accuracy VOUT -3 Adjustable Voltage VADJ 0.588 Adjustable bias current IADJ_Bias Maximum Output Current IOUT_Max Typ. Max. Units 3 % 0.600 0.612 V 10 100 nA 700 mA Load Regulation IOUT= 0 – 700mA 0.6 % Line Regulation VIN=3.0 – 12V; IOUT=100mA 0.15 % Supply Current ISUP VIN=3.3V, Io=0A 120 Shutdown Current ISHDN VIN=3.3V, VEN=0V <1 µA 800 mA Current Limit Dropout Voltage ILIM Output Noise Voltage 220 IOUT=250mA; VOUT=95% of VOUT(NOM) 300 IOUT=500mA; VOUT=95% of VOUT(NOM) 425 IOUT=750mA; VOUT=95% of VOUT(NOM) 600 F=10KHz Io=20mA 33 VDO ΔVOUT/ΔVIN PSRR IOUT=100mA; VOUT=95% of VOUT(NOM) 150 en µA mV BW: 100Hz–100 KHz COUT = 22µF ILOAD = 150mA No CBYP dB 118 µV(rms) CBYP = 10nF 33 Enable Threshold Low VEN(L) 1 V Enable Threshold High VEN(H) 1.1 V Input Enable Low Current IEN(L) VEN = 0V Input Enable High Current IEN(H) VEN = 1.5V Thermal Shutdown TSD 145 °C TSD_HYS 15 °C Thermal Shutdown Hysteresis Notes: 1. 2. 3. 0 10 nA 150 300 nA Stresses above those listed in Absolute Maximum Ratings may cause permanent damage to the device. Measured on approximately 1” square of 1 oz. copper. The total power dissipation for SO-8 EDP package is recommended to 2.5W rated at 25⁰C ambient temperature. 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 3109 Mic cropower 700mA 7 Low w Noise Fa ast Transie ent Respon nse LDO Ad djust (ADJ) Voltage V Temperature Varriation (Adjus stable Voltag ge Option) 0.606 Output Voltage Error (%) Adjust Voltage (V) Ty ypical Perfo ormance Characteris C stics (TA = 25°C 2 unless otherwise o sp pecified) 0.604 0.602 0.600 -50 -25 0 25 50 7 75 R VO = 1.8V, IO = 100mA Line Regulation 0.2 0.1 0.0 -0.1 -0.2 100 12 25 6 9 Input Voltage (V) 3 Ambient Temperature e (ºC) ‐50°C 25 20 25°C 15 10 5 100°C 0 0 1 100 200 3 300 400 500 600 Shutdown Current (µA) IGND vs s. Output Currrent VO=1.8V V, Vin=2.5V Shutd down Curren nt vs. Input Voltage V 50 125°C 40 30 20 25°C 10 0 70 00 0 1 Outpu ut Current (A A) Output Change (%) O t t Voltage V lt Ch Ground Current (mA) 30 12 2 3 4 5 6 7 8 9 10 11 12 oltage (V) Input Vo Loa ad Regulation n 0.2 0 -0.2 -0.4 -0.6 0.0 02/11/2010 0 0.1 Outtput Current (A) www.ad dvanced-mono olithic.com 4 1.0 Phone (925)) 443-0722 Fax (925)) 443-0723 A AMS3 3109 Mic cropower 700mA 7 Low w Noise Fa ast Transie ent Respon nse LDO Ty ypical Perfo ormance Characteris C stics (TA = 25°C 2 unless otherwise o sp pecified) Dropout Voltage (mV) 600 500 400 100°C 25°C 300 ‐50°C 200 100 VOUT = 1.8V Dropout Voltage (mV) VDO vs. Output O Curren nt 700 VDO vs. Tempera ature (IO = 70 00mA) 7 700 6 600 5 500 4 400 3 300 2 200 0 0 1 100 200 300 3 400 5 500 600 700 -50 Outputt Current (mA A) 100 Enable Starrt-Up Load Transient 50mA to 550mA A, VOUT=1.8V, VIN=3.3V CIN= COUT=4.7µF 02/11/2010 0 0 25 50 75 -25 Ambient Tem mperature (°C) IOUT = 0 to 350mA, VOUT = 1.8V, VIN = 3.0V, CIN=C = OUT=10µF www.ad dvanced-mono olithic.com 5 Phone (925)) 443-0722 Fax (925)) 443-0723 AMS3109 Micropower 700mA Low Noise Fast Transient Response LDO Functional Block Diagram Figure 1: Block Diagram of AMS 3109 02/11/2010 www.advanced-monolithic.com 6 Phone (925) 443-0722 Fax (925) 443-0723 AMS3109 Micropower 700mA Low Noise Fast Transient Response LDO Device Summary The AMS3109 is a high voltage low drop out linear regulator with a current capability of up to 700mA. The LDO has an input voltage range of 1.5V to 12V with an output voltage as low as 0.6V and is stable with a wide range of ceramic, tantalum, and electrolytic output capacitors. Shutdown/Enable The enable (on/off) input threshold voltage is 1.1V. When disabled the LDO quiescent current decreases to a typical value of <1µA. 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 800mA. 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 a larger value 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. Bypass Capacitor Whether the LDO is configured to be in a fixed or adjustable voltage configuration, connecting a capacitor between the ByPass (BYP) pin and ground can significantly reduce output noise. Values can range from 0pF to 10nF, depending on the sensitivity to output noise in the application. The start-up speed of the AMS3109 is inversely proportional to the size of the bypass capacitor. Applications requiring a slow ramp-up of output voltage should consider larger values of bypass capacitance. Likewise, if rapid turnon is necessary, consider omitting CBYP. 02/11/2010 Because the ByPass (BYP) pin is high-impedance, careful considering must be taken in the PCB layout to minimize noise pickup, and capacitors must be selected to minimize current leakage. Current leakage into the BYP pin will directly affect the regulator’s accuracy and should be kept low as possible. Using high quality ceramic and film types capacitors are recommended for their low leakage characteristics. Adjustable Feedback Resistor Selection AMS 3109 uses a 0.6V reference voltage at the positive terminal of the error amplifier. To set the output voltage a programming resistor from the adjust pin (ADJ) to ground must be selected (See Pg.1). A 10kΩ resistor is a good selection for a programming resistor R2. A higher value may result in an excessively sensitive feedback node while a lower value will draw more current and degrade the light load efficiency. The equation for selecting the voltage specific resistor is: R1 = Vout Vref -1 ·R2 = 1.8V 0.6V -1 ·10kΩ = 20kΩ Table 1: Adjustable Feedback Resistor values R1 (kΩ) VOUT (V) (R2=10kΩ) 1.8 20.0 2.5 31.6 3.3 45.3 5.0 73.2 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. Adjustable (ADJ) Feedback Resistors. The adjustable feedback resistors should be placed as close as possible the IC. Minimize the length of the trace from the feedback pin to the resistors. This is a high impedance node susceptible to interference from external RF noise sources. 3. Ground. 4. For good thermal performance vias are required to couple the exposed tab of the SO-8 package to the PCB ground plane. The via diameter should be 0.3mm to 0.33mm positioned on a 1.2mm grid. www.advanced-monolithic.com 7 Phone (925) 443-0722 Fax (925) 443-0723 AMS3109 Micropower 700mA Low Noise Fast Transient Response LDO Output Power and Thermal Limits The AMS3109 junction temperature and current capability depends on the internal dissipation and the junction to case thermal resistance of the SO-8 exposed paddle package. Tjmax = Pd·θjc + Tpcb + Tamb The internal losses contribute to the junction temperature rise above the paddle and PCB temperature. Additionally, the paddle and PCB temperature will be elevated due to the total losses of the LDO and of other circuits mounted to the PCB. 02/11/2010 www.advanced-monolithic.com 8 Phone (925) 443-0722 Fax (925) 443-0723 AMS3109 Micropower 700mA Low Noise Fast Transient Response LDO Figure 2: AMS3109 Evaluation Board Top Side Figure 3: AMS3109 Evaluation Board Bottom Side 2 1 1 C4 10nF 2 3 4 Vin U1 BYP EN NC NC GND ADJ VIN VOUT Enable 8 7 6 R1 5 AMS3109 C2 22uF C1 10uF C3 n/a R2 10.0k gnd gnd Vout Figure 4: AMS3109 Evaluation Board Schematic Component C1 C2 C3 C4 1.2V 1.8V 2.5V 3.3V 5.0V R1 R2 U1 02/11/2010 Table 2: AMS3109 Evaluation Board Bill of Materials Value Manufacturer Manufacturer Part Number 10µF, 50V, X5R, 1210, Ceramic 22µF, 10V, X5R, 0805, Ceramic Optional Feedforward 10nF, 50V,20%,X7R,0603 10.0kΩ, 0.1W, 0603 1% 20.0kΩ, 0.1W, 0603 1% 31.6kΩ, 0.1W, 0603 1% 45.3kΩ, 0.1W, 0603 1% 73.2kΩ, 0.1W, 0603 1% 10.0kΩ, 0.1W, 0603 1% Linear Regulator Taiyo Yuden Taiyo Yuden UMK325BJ106KM-T LMK212BJ226MG-T Murata Various Various Various Various Various Various AMS GRM188R71H103MA01 CRCW0603xxKxFKEA CRCW0603xxKxFKEA CRCW0603xxKxFKEA CRCW0603xxKxFKEA CRCW0603xxKxFKEA CRCW060310K0FKEA AMS3109 SOIC-8 EDP www.advanced-monolithic.com 9 Phone (925) 443-0722 Fax (925) 443-0723 AMS3109 Micropower 700mA Low Noise Fast Transient Response LDO Ordering Information Device Package AMS3109S(1)(2) SOIC-8 EDP 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 Outline Drawing and Landing Pattern SOIC-8 package dimensions are inches (millimeters) unless otherwise noted. 0.189-0.197* (4.801-5.004) 8 7 6 8 5 0.228-0.244 (5.791-6.197) 5 0.150-0.157** (3.810-3.988) 1 2 3 0.090 (2.28) 0.102 (2.59) 1 4 2 3 4 0.010-0.020 x 45° (0.254-0.508) 0.053-0.069 (1.346-1.752) 0.004-0.010 (0.101-0.254) 0.014-0.019 (0.355-0.483) 0.024(0.61) 0.123 (3.12) 0.137 (3.48) 7 6 0.050 (1.270) TYP 0.008-0.010 (0.203-0.254) 0°-8° TYP 0.016-0.050 (0.406-1.270) S ( SO- 8 ) AMS DRW # 042293 *DIMENSION DOES NOT INCLUDE MOLD FLASH. MOLD FLASH SHALL NOT EXCEED 0.006" (0.152mm) PER SIDE 0.050(1.27) 0.063(1.60) **DIMENSION DOES NOT INCLUDE INTERLEAD FLASH. INTERLEAD FLASH SHALL NOT EXCEED 0.010" (0.254mm) PER SIDE 0.105(2.67) 0.213(5.41) 0.138 (3.50) RECOMMENDED LAYOUT PATTERN 02/11/2010 www.advanced-monolithic.com 10 Phone (925) 443-0722 Fax (925) 443-0723