AT9173EG

AME, Inc. AT9173 Bus Termination Regulator n General Description The AT9173 is a voltage regulator which could convert the input voltage ranging from 1.8V to 5V to an output voltage that user settled. The regulator can provide sourcing or sinking current.The AT9173, used in conjunction with series termination resistors, provides an excellent voltage source for active termination schemes of high speed transmission lines as those seen in high speed memory buses and distributed backplane designs. The voltage output of the regulator can be used as a termination voltage for DDR SDRAM. Current limits in both sourcing and sinking mode, plus on-chip thermal shutdown make the circuit tolerant of the output fault conditions. n Features ● Support Both DDR I (1.25VTT) and DDR II of Sourcing and Sinking Current (0.9VTT) Requirements ● Capable ● ● Current-limiting Protection Thermal Protection Power MOSFETs Termination Voltages for SSTL-2 ● Integrated ● Generates ● High ● ● Accuracy Output Voltage at Full-Load Adjustable VOUT by External Resistors Minimum External Components for Standby or Suspend Mode Operation with High-impedance Output ● Shutdown n Applications ● DDRI/DDRII ● ● ● Memory Termination Supply Active Termination Buses Desktop PC,NoTebook,Server and workstation Graphic Card Top Box Embedded System ● Set ● n Typical Application DDR _2.5 V AT9173 A-SOP 8 VCC_ 3.3 V 1 R2 100KO C4 0.1 uF C2 470uF 2 3 4 VIN GND REFEN VOUT VCNTL VCNTL 8 7 VCNTL VCNTL 6 5 DDR_VTT 1.25V/1.5A R4 100KO AT9173A SOP-8 C8 4.7uF C6 470uF Rev. C.04 1 AME, Inc. AT9173 Bus Termination Regulator n Typical Application(Contd.) VCC_ 3.3V DDR_2.5V AT9173 E-SOP 8 / PP VIN 1 NC G ND _PA D NC VCNTL NC 5 8 7 6 DDR_ VTT 1 .25V/2A R1 100 KO C3 0.1uF C4 470uF GND 2 REFEN 3 4 VOUTL R3 100KO AT9173E SOP-8/PP C7 4.7uF C5 470uF n Function Block Diagram VCNTL VIN Thermal Sensor + Thermal & Over Current Protection Circuit REFEN + GND VOUT VCNTL 2 Rev. C.04 AME, Inc. AT9173 Bus Termination Regulator n Pin Configuration SOP- 8 Top View 8 7 6 5 SOP- 8/PP Top View AT9173A 1. IN 2. GND 3. REFEN 4. OUT 5. VCNTL 6. VCNTL 7. VCNTL 8. VCNTL 8 7 6 5 AT9173 1 2 3 4 AT9173 1 2 3 4 AT9173E 1. IN 2. GND 3. REFEN 4. OUT 5. NC 6. VCNTL 7. NC 8. NC n Pin Description Pin name Pin Description Input voltage pin which supplies current to the V OUT pin. Connect this pin to a welldecoupled voltage to prevent the input rail from dropping during large load transient. A large and low ESR capacitor is recommended to use that should be placed as close as possible to the V IN pin. Ground pin. Tie directly to ground plance. Voltage control pin which supplies the internal control circuitry and provides the drive voltage. The driving capability of output current is proportioned to the VCNTL. Connect this pin to 5V bias supply to handle large output current with at least 1uF capacitor from this pin to GND. An important note is that VIN should be kept lower or equal to VCNTL. Reference voltage input and active low shutdown control pin. Two resistors dividing down the VIN voltage on this pin to create the regulatedoutput voltage. Pulling this pin to GND to turn off the device by an open-drain, such as 2N7002 N-Channel MOSFET. Regulator output. V OUT is regulated from REFEN voltage that is used to terminate the bus resistors. It is capable of sinking and sourcing current while regulating the output rail. To maintain adequate large signal transient response, typical value of 1000uF electrolytic capacitor with 10uF ceramic capacitors are recommended to reduce the effects of current transients on VOUT. No Connection. Not internal connected. Connected to GND plance for better heat dissipation. IN GND VCNTL REFEN OUT NC* GND Pad* * By SOP-8/PP only Rev. C.04 3 AME, Inc. AT9173 Bus Termination Regulator n Ordering Information Part Number AT9173AG Marking AT9173AG yyww* AB xxxxxxx##** AT9173EG yyww* AC xxxxxxx##** Output Voltage ADJ Package SOP-8 Operating Temp. Range -25 C to +85 C AT9173EG ADJ SOP-8/PP o o Note: * yy and ww represents the data code. ** XXXXXXX represents the wafer lot number, ## represents the wafer number 4 Rev. C.04 AME, Inc. AT9173 Bus Termination Regulator n Absolute Maximum Ratings Parameter Input Voltage. V IN to GND VCNTL to GND ESD Rating (Human Body Mode) Storage Temperature Lead Temperature (Soldering. 5sec) Symbol VIN VCNTL VESD TSTG TL Maximum 6 6 2 150 245 Unit V V KV O O C C n Recommended Operating Conditions Parameter Supply Voltage 1 Supply Voltage 2 Output Current of V OUT Pin * Junction Temperature Symbol VIN VCNTL *IOUT TJ Rating 1.8 or 2.5 3.3 -2 to 2 -25 to 125 Unit V V A O C *The symbol "+" means the VOUT sources current to load; the symbol "-" means the VOUT sinks current to GND n Thermal Characteristics Parameter Thermal Resistance* (Junction to Case) Package SOP-8 SOP-8/PP SOP-8 SOP-8/PP SOP-8 Die Attch Non-Conductive Epoxy Conductive Epoxy Non-Conductive Epoxy Conductive Epoxy Non-Conductive Epoxy Conductive Epoxy Symbol Maximum 55 θJC 19 Unit O C/W Thermal Resistance (Junction to Ambient) 120 θJA 84 1300 PD 1450 mW Internal Power Dissipation SOP-8/PP Rev. C.04 5 AME, Inc. AT9173 Bus Termination Regulator n Electrical Specifications Limits in standard typeface are for TA=25℃, unless otherwise specified: VIN=2.5V, VCNTL=3.3V, VREFEN =0.5V IN. Parameter Output Offset Voltage Load Regulation (DDR 1/2) Input Voltage Range (DDR 1/2) Operating Current of VCNTL Current In Shutdown Mode Short Circuit Protection SOP-8 Current Limit PSOP-8 Current Limit Over Temperature Protection Thermal Shutdown Temperature Thermal Shutdown Hysteresis Symbol VOS VLOAD VIN V CNTL ICNTL ISHDN ILIMIT ILIMIT Test Condition I OUT=0A (Note 1) I L=0~1.5A (Fig 4) I L=0~-1.5A KEEP VCNTL ≥ VIN on operation power on and power off No Load VREFEN < 0.2V, RL=180Ω (Fig 5) Min -20 -20 -20 1.6 2.5 Typ 0 0 0 2.5/1.8 3.3 1.4 25.6 Max 20 20 20 4 6 Units mV mV V mA µA Fig 6,7 Fig 6,7 2.1 2.4 A A TSD 3.3V ≤ VCNTL ≤ 5 V 125 O C Guaranteed by design 30 Note1: VOS offset is the voltage measurement defined as VOUT subtracted from VREFEN . 6 Rev. C.04 AME, Inc. AT9173 Bus Termination Regulator n Application Information VCNTL = 3.3V VIN = 1.8V RTT CIN CCNTL R1 VIN REFEN VCNTL 2N7002 EN AT9173 GND VOUT R2 CSS COUT RDUMMY R 1 = R2 = 100KO, RTT = 50O / 33O / 25O C OUT(MIN) = 10uF (Ceramic) + 1000uF under the worst case testing condition R DUMMY = 1KO as for VOUT discharge when V IN is not presented but VCNTL is presented C SS = 1uF, CIN = 470uF (Low ESR), C CNTL = 47uF n Application Circuit Typical application circuit is used as a regulator to provide termination voltage in double data rate (DDR) memory system. The regulator could source and sink up to 2A peak current. The output voltage will follow REFEN which generated by two external dividing resistors down from VIN or to the desired output voltage set externally by forcing a voltage level to REFEN pin. To add a shutdown function , connect a small transistor to REFEN pin. To perform shutdown function , put a logic high 5V signal to EN yield a low (0V) to REFEN pin thus force output voltage to zero voltage. The capacitor Css is used to softstart the output voltage since V OUT will follow REFEN. Time constant for this circuit is Css*(R1//R2). The Css could also used as the bypass capacitor to filter out noise in REFEN pin. So carefully layout should put Css close to REFEN pin to maintain noise immunity. The C IN an C CNTL is used as power decoupling capacitor. COUT is composed of 10uF ceramic plus 1000uF electrolyte capacitors. The first one is to used as high frequency filter and the second one is used to reduce voltage drop during load regulating. n General Regulator The AT9173 can be used as a general regulator. To get a desired output voltage, put a reference voltage to REFEN pin or dividing resistors down a input voltage source. To drive inside N-Channel MOSFET the VCNTL should be larger than VIN to get enough driving voltage. The minimum dropout voltage could be IOUT *0.1, where IOUT is the output current. n Layout issue Place a bypass capacitor as close as possible to VIN and VCNTL pin is necessary. A low ESR capacitor is recommended for this bypass capacitor. Use wide and short PCB traces to connect in between VIN power source VOUT to reduce PCB resistance thus to reduce undesired power dissipation. Rev. C.04 7 AME, Inc. AT9173 Bus Termination Regulator n Thermal issue AT9173 has a internal thermal protection to protect the device at any overload conditions. For safety reason the operation junction temperature should not exceed 125 ℃. The dissipation of the device is PD = (V IN − V OUT ) xI OUT And also the maximum power dissipation is PD , MAX = (T J , MAX − T A ) / θ JA Where Tj,max is the maximum operation junction 125 degree C, Ta is the ambient temperature and the is θ JA the junction to ambient thermal resistance. The junction to ambient thermal resistance is 70 ℃ /W for exposed pad SOP-8 package. It can be dramatically reduced by placing a large area PCB trace under exposed pad to emit heat generated by the die attached to the exposed pad. 8 Rev. C.04 AME, Inc. AT9173 Bus Termination Regulator n Test Circuit Fig 4: Output Voltage Tolerance, △ VOUT Fig 5: Current in Shutdown Mode, ISHDN Rev. C.04 9 AME, Inc. AT9173 Bus Termination Regulator Figure 6: Current Limit for High Side, ICLHIGH Figure 7: Current Limit for Low Side, ICLLOW 10 Rev. C.04 AME, Inc. AT9173 Bus Termination Regulator n Typical Characteristics Rev. C.04 11 AME, Inc. AT9173 Bus Termination Regulator n Operation Waveforms DDR1 Load Transient Response VIN=2.5V, VCNTL=3.3V VREF is 1.25V supplied by a regulator COUT=1000uF/35V IOUT slew rate = +-0.25A/mS + 0 A→ + 1.5 A→ + 0 A + 0 A→ + 2 A → + 0 A + 0 A→ + 2.5 A→ + 0 A Ch1= IOUT ,Ch4 = VOUT Ch1= I OUT ,Ch4 = VOUT Ch1= I OUT ,Ch4 = VOUT Load Transient Response VIN=2.5V, VCNTL=3.3V VREF is 1.25V supplied by a regulator COUT=1000uF/35V IOUT slew rate = +-0.25A/mS - 0 A→ - 1.5 A→ - 0 A - 0 A → - 2 A→ - 0 A - 0 A→ - 2.5 A - 0 A → Ch1= IOUT ,Ch4 = VOUT Ch1= I OUT ,Ch4 = VOUT Ch1= IOUT ,Ch4 = VOUT 12 Rev. C.04 AME, Inc. AT9173 Bus Termination Regulator n Operation Waveforms DDR2 Load Transient Response VIN=1.8V, VCNTL=3.3V VREF is 0.9V supplied by a regulator COUT=1000uF/35V IOUT slew rate = +-0.25A/mS + 0 A → + 1.5 A→ + 0 A + 0 A→ + 2 A→ + 0 A Ch1= V OUT, Ch4= IOUT Ch1= VOUT ,Ch4= IOUT Load Transient Response VIN=1.8V, VCNTL=3.3V VREF is 0.9V supplied by a regulator COUT=1000uF/35V IOUT slew rate = +-0.25A/mS - 0 A→ - 1.5 A - 0 A → - 0 A → - 2 A→ - 0 A Ch1= VOUT , Ch4 = IOUT Ch1= VOUT , Ch4 = IOUT Rev. C.04 13 AME, Inc. AT9173 Bus Termination Regulator n Date Code Rule Marking A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A Date Code W W W W W W W W W W W W W W W W W W W W Year xxx0 xxx1 xxx2 xxx3 xxx4 xxx5 xxx6 xxx7 xxx8 xxx9 n Tape and Reel Dimension SOP- 8 P W AME PIN 1 AME Carrier Tape, Number of Components Per Reel and Reel Size Package SOP-8 Carrier Width (W) 12.0±0.1 mm Pitch (P) 4.0±0.1 mm Part Per Full Reel 2500pcs Reel Size 330±1 mm 14 Rev. C.04 AME, Inc. AT9173 Bus Termination Regulator n Tape and Reel Dimension SOP- 8/PP P W AME PIN 1 AME Carrier Tape, Number of Components Per Reel and Reel Size Package SOP-8/PP Carrier Width (W) 12.0±0.1 mm Pitch (P) 4.0±0.1 mm Part Per Full Reel 2500pcs Reel Size 330±1 mm Rev. C.04 15 AME, Inc. AT9173 Bus Termination Regulator n Package Dimension SOP-8 Top View C Side View SYMBOLS A MILLIMETERS MIN 1.35 0.10 0.33 0.19 4.80 3.80 0.40 5.80 0 o INCHES MIN 0.05315 0.00394 0.01299 0.00748 0.18898 0.14961 MAX 1.75 0.30 0.51 0.25 5.33 4.00 1.27 6.30 0.10 8 o MAX 0.0689 0.01181 0.02008 0.00984 0.20984 0.15748 H E A1 A2 B C 1.473 REF 0.05799 REF D L θ D E e L H Front View 7 (4X) o 1.27 BSC 0.05000 BSC 0.01575 0.05000 0.22835 0.24803 0 o A2 y θ 0.00394 8 o B SOP-8/PP Top View D1 Side View θ A1 e A SYMBOLS A MILLIMETERS MIN 0 1.350 0.100 3.750 5.700 0.300 0.310 4.720 INCHES MIN 0 0.053 0.004 0.148 0.224 0.012 0.012 0.186 MAX 1.750 0.150 1.600 0.250 4.150 6.300 0.900 0.510 5.120 MAX 0.069 0.006 0.063 0.010 0.163 0.248 0.035 0.020 0.202 E1 E2 E L1 C 1 A1 A2 C E E1 L b D Front View D A2 A e θ E2 D1 1.270 BSC 0 o 0.05 BSC o A1 b e 8 0 o 8 o 2.150 2.150 2.500 3.400 0.085 0.085 0.098 0.134 16 Rev. C.04 www.ame.com.tw E-Mail: sales@ame.com.tw Life Support Policy: These products of AME, Inc. are not authorized for use as critical components in life-support devices or systems, without the express written approval of the president of AME, Inc. AME, Inc. reserves the right to make changes in the circuitry and specifications of its devices and advises its customers to obtain the latest version of relevant information. © AME, Inc. , December 2007 Document: ATT-DS9173-C.04 Corporate Headquarter AME, Inc. 2F, 302 Rui-Guang Road, Nei-Hu District Taipei 114, Taiwan. Tel: 886 2 2627-8687 Fax: 886 2 2659-2989 U.S.A (Subsidiary) Analog Microelectronics, Inc. 3100 De La Cruz Blvd., Suite 201 Santa Clara, CA. 95054-2046 Tel : (408) 988-2388 Fax: (408) 988-2489