SP2996B 2 Amp DDR Bus Termination Regulator FEATURES ■ Capable of sourcing and sinking 2A Continuous current ■ Supports both DDR1 (1.25VTT) and DDR2 (0.9VTT) requirements ■ Low Output Voltage Offset, + 20mV ■ Thermal and Current Limit Protection ■ Integrated Power MOSFETs ■ Generates Termination for SSTL-2 ■ High Accuracy Output at Full Load ■ Adjustable VOUT by External Resistors ■ Minimal External Components ■ Available in 8 pin NSOIC package VIN 1 8 VCNTL 7 VCNTL REFEN 3 6 VCNTL VOUT 4 5 VCNTL SP2996B GND 2 8 Pin NSOIC Now Available in Lead Free Packaging APPLICATIONS ■ DDR Memory Termination ■ Active Bus Termination ■ Supply Splitter DESCRIPTION The SP2996B voltage regulator is designed to convert voltage supplies ranging from 1.6V to 6V into a desired output voltage which is adjusted by an external resistor divider. The regulator is capable of sourcing or sinking up to 2A of Continuous current while regulating an output voltage to within 20mV. The SP2996B provides an excellent voltage source for active termination schemes of high speed transmission lines such as those seen in high speed memory buses and distributed backplane designs when used in conjunction with series termination resistors. The voltage output of the regulator can be used as a termination voltage for DDR SDRAM, and it meets the JEDEC SSTL-2 and SSTL-3 specifications . Current limits in both sourcing and sinking mode, plus on-chip thermal shutdown make the circuit tolerant of output fault conditions. TYPICAL APPLICATIONS CIRCUIT VCNTL= 3.3V VIN = 2.5V 1 VCNTL R1 100kΩ ¤ 3 VREF CES7002A EN R2 100kΩ VOUT SP2996B C1 1µF GND 2 Date: 3/16/06 + 5,6,7,8 VIN SP2996B 2A Termination Regulator 1 CIN 470µF Tant CCNTL 10µF 4 VOUT + COUT 220µF Tant © Copyright 2006 Sipex Corporation ABSOLUTE MAXIMUM RATINGS Supply Voltage ................................................... -0.4V to 7V Operating Temperature Range.......................-40°C to +85°C Junction Temperature ............. ..................................125°C Storage Temperature Range........................-65°C to +150°C ELECTRICAL CHARACTERISTICS VIN = 2.5V, VCTRL = 3.3V, VREF = 0.5VIN, COUT = 10µF (Ceramic), TA = 25ºC, unless otherwise specified. (Note 1) Parameter Test Conditions Min Typ Max Keep V CTRL ≥ VIN on operation power on and power off sequences 1.6 2.5/1.8 - V CNTL IOUT = 0mA 3.0 Output Voltage V OUT IOUT = 0mA Output Offset Voltage VOS No Load Input Voltage Range (DDR 1/2) (Note 5) Load Regulation (DDR 1/2) Quiescent Current Operating Current of VCNTL Symbol VIN ICNTL Bias Current of VREF Current Limit V 3.3 6 VREF V -20 - 20 IOUT = 0.1mA to +2A - 10 25 IOUT = 0.1mA to -2A - 10 25 VREF < 0.2V, VOUT = OFF - 8 30 µA No Load - 3 10 mA VREF = 1.25V - - 1 µA Note 4 2.2 3 4.5 A 3.3V ≤ VCNTL ≤ 5V Guaranteed by design 125 150 - ºC Guaranteed by design - 30 - ºC - - ∆ V LOR IQ IIL Units mV mV Thermal Protection Thermal Shutdown Temperature (Note 5) TSD Thermal Shutdown Hysteresis Shutdown Specifications Shutdown Threshold Shutdown Threshold VTRIGGER Output ON ( V REF = ZeroV ---->1 .25V) 0.8 VTRIGGER Output OFF ( V REF = 1.25V ----> ZeroV) - V - θJA 160 θJC 40 Thermal Resistance 0.2 ºC/W Note 1 . Specifications are tested for production at TA = 25ºC . Specifications over the -40ºC to 85ºC operating temperature range are assured by design, characterization and correlation with Statistical Quality Controls (SQC). Note 2. VOS offset is the voltage measurement defined as VOUT subtracted from VREF. Note 3. Load regulation is measured at constant junction temperature, using pulse testing with a low ON time. Note 4. Current limit is measured by pulsing a short time. Note 5. In order to safely operate your system, VCTRL must be > VIN. Date: 3/16/06 SP2996B 2A Termination Regulator 2 © Copyright 2006 Sipex Corporation PIN DESCRIPTIONS Pin Name Pin Number Description (8 pin NSOIC) VIN 1 Power Input Voltage GND 2 Ground REFEN 3 Reference Voltage Input V OUT 4 Output Voltage V CNTL 5 Voltage for the driver circuit and all analog blocks V CNTL 6 Voltage for the driver circuit and all analog blocks V CNTL 7 Voltage for the driver circuit and all analog blocks V CNTL 8 Voltage for the driver circuit and all analog blocks BLOCK DIAGRAM Date: 3/16/06 SP2996B 2A Termination Regulator 3 © Copyright 2006 Sipex Corporation TEST CIRCUITS 2.5V 3.3V VIN 1.25V VCNTL VOUT VOUT REFEN GND COUT V IL Testing Output Voltage Tolerance, ∆VLOAD 2.5V 3.3V A VIN 1.25V ZeroV VCNTL 1.25V VOUT VOUT REFEN 0V GND RL COUT V RL & COUT Time Delay Testing Current in Shutdown Mode, ISHDN Date: 3/16/06 SP2996B 2A Termination Regulator 4 © Copyright 2006 Sipex Corporation TEST CIRCUITS 2.5V 3.3V VIN VCNTL VOUT 1.25V VOUT REFEN GND A COUT V IL Testing Current Limit for High Side, ILIMIT Power Supply with Current Limit 3.3V 2.5V A VIN VCNTL IL VOUT VOUT REFEN 1.25V GND COUT V Testing Current Limit for Low Side, ILIMIT 3.3V 2.5V A VIN VREFEN 1.25V VCNTL 0.8V Shutdown Threshold VOUT VOUT REFEN 0.2V GND RL VOUT COUT V VOUT goes low for VREFEN < 0.2V VOUT goes low for VREFEN > 0.8V Testing REFEN Pin Shutdown Threshold, , VTRIGGER Date: 3/16/06 SP2996B 2A Termination Regulator 5 © Copyright 2006 Sipex Corporation TYPICAL PERFORMANCE CHARACTERISTICS Turn-on Threshold Vs. Temperature Turn-On Threshold vs. Temperature 520 Threshold Voltage (mV) Threshold Voltage (mV) 520 480 440 400 VCTRL = 3.3V Vin = 2.5V 360 320 -40 -20 0 20 40 60 Temperture 80 100 480 440 400 320 -40 120 -20 0 20 40 60 Temperature ºC 5.0 4 4.0 Current (A) 5 Sourcing 3 2 VCTRL = 3.3V Vin = 2.5V 1 80 2.0 VCTRL = 5V Vin = 2.5V 1.0 Vout = 1.25V 0.0 -40 0 -20 0 20 40 60 Temperature 80 120 3.0 Vout = 1.25V -40 100 ºC Sourcing Current (Peak) vs. Temperature Sinking Current (Peak) vs. Temperature Sinking Current (A) VCTRL = 3.3V Vin = 2.5V 360 100 120 -20 0 20 40 Temperature ºC 60 80 100 120 ºC Output Voltage Offset vs. Temperature 4.50 Output Voltage Offset (mV) 4.00 3.50 3.00 2.50 2.00 VCTRL = 5V 1.50 Vin = 2.5V 1.00 0.50 -40 Vout = 1.25V -20 0 20 40 Temperature Date: 3/16/06 60 80 100 120 (ºC) SP2996B 2A Termination Regulator 6 © Copyright 2006 Sipex Corporation TYPICAL PERFORMANCE CHARACTERISTICS VCNTL=3.3V, VCNTL=3.3V VIN=2.5V VIN=2.5V VREF=1.25V VREF=1.25V Output Short-Circuit (Sourcing) Output Short-Circuit (Sinking) VCNTL=3.3V, VCNTL=3.3V VIN=2.5V VIN=1.8V VREF=0.9V VREF=1.25V Transient Response at 1.25VTT/2A Date: 3/16/06 Transient Response at 0.9VTT/2A SP2996B 2A Termination Regulator 7 © Copyright 2006 Sipex Corporation APPLICATION INFORMATION Internal parasitic diode Avoid forward-biasing the internal parasitic diode, VOUT to VCNTL, and VOUT to VIN. Positive voltage should not be applied to the output if VIN and VCNTL are not present. Layout Considerations The SP2996B is offered in the NSOIC-8 package , resulting in attention needing to be paid to dissipating heat effectively when it operates in high current. In order to prevent maximum junction temperature from being exceeded, suitable copper area is necessary. The large copper area at VCNTL pins is available, and by taking advantage of this, much heat dissipation is attained. Use vias to direct heat into the bottom layer as the layout examples show below. All capacitors should be placed as close as possible to relative pins. Considerations for designing, resistance of voltage divider When the reference voltage is programmed below 0.2V the pulldown capability of the internal NMOS transistor is limited. It is recommened to place a filter capacitor from VRE to ground in order to reduce sensitivity to noise and improve power up characteristics (soft start). Top layer Date: 3/16/06 Bottom layer SP2996B 2A Termination Regulator 8 Placement © Copyright 2006 Sipex Corporation PACKAGE: 8 PIN NSOIC D D/2 SIDE VIEW 7 8 5 6 A2 A E/2 E1/2 A1 2 1 Pin1 Designator to be within this INDEX AREA (D/2 x E1/2) Seating Plane E E1 4 3 (L1) e b TOP VIEW ø1 h FRONT VIEW ø2 h R1 Gauge Plane R L2 ø 8 Pin NSOIC SYMBOL A A1 A2 b c E E1 e h L L1 L2 R R1 ø ø1 ø2 D Seating Plane L JEDEC MS-012 MIN NOM MAX MIN 1.35 0.10 1.25 0.31 0.17 6.00 BSC 3.90 BSC 1.27 BSC 1.75 0.25 1.65 0.51 0.25 0.053 0.004 0.049 0.012 0.007 0.50 1.27 0.010 0.016 8º 15º - 0.003 0.003 0º 5º 0º 0.25 0.40 SP2996B 2A Termination Regulator 9 c Variation AA Dimensions in Inches Conversion Factor: 1 Inch = 25.40 mm Dimensions in Millimeters: Controlling Dimension 1.04 REF 0.25 BSC 0.07 0.07 0º 5º 0º 4.90 BSC SIPEX Pkg Signoff Date/Rev: Date: 3/16/06 ø1 NOM MAX 0.069 0.010 0.065 0.020 0.010 0.236 BSC 0.154 BSC 0.050 BSC 0.020 0.050 0.041 REF 0.010 BSC 8º 15º 0.193 BSC JL Aug16-05 / Rev A © Copyright 2006 Sipex Corporation ORDERING INFORMATION PART NUMBER TEMPERATURE RANGE PACKAGE SP2996BEN ........ ............................................................... -40ºC to 85ºC....................................................8 Lead NSOIC SP2996BEN/TR .. ............................................................... -40ºC to 85ºC................................................... 8 Lead NSOIC Available in lead free packaging. To order add "-L" suffix to part number. Example: SP2996BEN/TR = standard; SP2996BEN-L/TR = lead free. /TR = Tape and Reel Pack quantity is 2,500 for NSOIC. Date: 3/16/06 SP2996B 2A Termination Regulator 10 © Copyright 2006 Sipex Corporation