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Texas Instruments LP2997MX/NOPB
- Part No.:
- LP2997MX/NOPB
- Manufacturer:
- Texas Instruments
- Category:
- Power Management - Specialized
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
LP2997MX/NOPB.pdf
- Description:
- IC REGULATOR DDR-II TERM 8-SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:1,036
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Product details
Overview
LP2997MX/NOPB from Texas Instruments is a linear DDR-II termination regulator designed to meet JEDEC SSTL-18 specifications. It sources and sinks up to ±500 mA while regulating VTT to precisely VDDQ/2 (e.g., 0.9 V at VDDQ = 1.8 V), features integrated VREF buffer, active-low shutdown for Suspend-to-RAM, and operates across 0°C to +125°C ambient. It serves as the bus termination voltage source in DDR-II memory subsystems.
For engineers reviewing the LP2997MX/NOPB datasheet, LP2997MX/NOPB pinout, LP2997MX/NOPB application, or LP2997MX/NOPB equivalent, key selection considerations include its dual-rail architecture (AVIN/PVIN separation), VSENSE remote sensing capability, thermal shutdown behavior, and SOIC-8 package compatibility with standard JEDEC board layouts.
Technical Context
The LP2997MX/NOPB implements a linear topology with split analog (AVIN) and power (PVIN) rails to minimize internal dissipation and improve thermal performance. Its high-speed op-amp feedback loop enables fast transient response to DDR-II bus current demands.
VTT regulation is achieved via internal 50 kΩ resistor divider referenced to VDDQ, ensuring precise VDDQ/2 tracking; VSENSE provides remote load regulation by sensing voltage at the bus midpoint. Shutdown mode tri-states VTT while maintaining active VREF output for chipset reference continuity.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VTT Output Voltage | 0.908 V (typ) at VDDQ = 1.8 V, IOUT = 0 A - matches JEDEC SSTL-18 termination requirement |
| Output Current | ±500 mA continuous - supports full DDR-II SDRAM bus termination under dynamic load |
| VREF Output | Buffered VDDQ/2 (0.910 V typ at VDDQ = 1.8 V) - supplies stable reference to Northbridge and DIMMs |
| Quiescent Current | 500 µA max (AVIN supply) - enables low-power operation during active state |
| Shutdown Current | 150 µA max (ISD) - reduces system power during Suspend-to-RAM without losing VREF |
| Thermal Shutdown | 165°C with 10°C hysteresis - protects device during overload or poor PCB thermal design |
| Package | SOIC-8 (D package, 6.5 mm × 4.4 mm) - industry-standard footprint with θJA = 151°C/W on JEDEC board |
Pinout & Package
LP2997MX/NOPB is housed in an 8-pin SOIC (Package D, JEDEC MS-012AA) with exposed pad not present - distinct from PowerPAD variant. Pin 1 is top-left corner (quadrant Q1), with GND at Pin 1 and VTT at Pin 8.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 GND | Ground reference | Primary return path for AVIN, PVIN, and internal circuitry; must be low-impedance connection |
| 2 SD | Active-low shutdown control | Pull low to tri-state VTT while retaining active VREF - enables Suspend-to-RAM functionality |
| 3 VSENSE | Remote feedback sense | Connects to midpoint of VTT bus plane to compensate for IR drop; improves load regulation accuracy |
| 4 VREF | Buffered reference output | Provides stable VDDQ/2 (0.91 V typ) to chipset/DIMM reference inputs; remains active in shutdown |
| 5 VDDQ | Reference input rail | Direct connection to DDR-II 1.8 V memory rail; sets VTT target via internal 50kΩ/50kΩ divider |
| 6 AVIN | Analog supply input | 2.2–5.5 V supply for control circuitry; decoupled with 0.1 µF ceramic capacitor near pin |
| 7 PVIN | Power stage supply input | 1.8 V or 2.5 V rail for output stage; must be ≤ AVIN; determines maximum sourcing headroom |
| 8 VTT | Regulated termination output | Sources/sinks ±500 mA to maintain VDDQ/2; connects directly to parallel termination resistors on DDR-II bus |
Key Features
| Feature | Design Value |
|---|---|
| No external resistors required | Internal 50 kΩ/50 kΩ divider sets VTT = VDDQ/2 - eliminates calibration components and layout sensitivity |
| VSENSE remote sensing | Enables <15 mV load regulation error across long VTT planes - critical for multi-DIMM motherboard designs |
| Suspend-to-RAM (STR) support | VTT tri-states while VREF remains active - preserves memory reference integrity during low-power states |
| Split-rail architecture | Separate AVIN (control) and PVIN (power) supplies reduce thermal stress and allow optimized PCB routing |
| Thermal shutdown with hysteresis | 165°C trip with 10°C hysteresis prevents oscillation during thermal overload - ensures safe recovery |
Applications
| DDR-II Memory Termination | SSTL-18 Bus Interface |
|---|---|
Use Scenario: Termination of bidirectional data/address/control lines in DDR-II SDRAM modules on desktop/server motherboards. IC Role / Device Role / Timing Role: Provides dynamically regulated VTT termination voltage equal to VDDQ/2, sourcing/sinking transient currents up to ±900 mA peak. Use Value: Ensures signal integrity across high-speed DDR-II buses by maintaining precise 0.9 V termination under varying load conditions. |
Use Scenario: Interface between memory controller and DDR-II DIMMs requiring JEDEC-compliant SSTL-18 signaling. IC Role / Device Role / Timing Role: Delivers stable VREF reference and tightly regulated VTT to match SSTL-18 input thresholds and drive strength requirements. Use Value: Eliminates need for discrete resistor networks and external op-amps, reducing BOM count and improving timing margin. |
| Low-Power Memory Subsystem | Thermally Constrained Embedded DDR |
Use Scenario: Power management in portable or fanless systems where Suspend-to-RAM is frequently used. IC Role / Device Role / Timing Role: Tri-states VTT on SD assertion while sustaining VREF - maintains memory retention voltage without drawing termination current. Use Value: Reduces system standby power by >60% versus always-on termination regulators, with no loss of reference stability. |
Use Scenario: DDR-II termination in space-constrained industrial controllers with limited airflow and no heatsink. IC Role / Device Role / Timing Role: Linear regulator with SOIC-8 package and 151°C/W θJA - enables thermal design using only PCB copper and vias. Use Value: Supports continuous ±500 mA operation at 70°C ambient when mounted on 2-oz copper with 6 thermal vias under package. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar DDR-II termination regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TPS51100DGQR | Switching architecture; higher efficiency but requires external inductor/filter; no integrated VREF buffer | Used where >85% efficiency is mandatory and board area allows inductor placement; lacks native STR support | Select when thermal budget is extremely tight and system can tolerate switching noise on VTT rail |
| LP2998MRX/NOPB | Same family, SO PowerPAD-8 package; θJA = 43°C/W vs 151°C/W; identical electrical specs and pinout | Preferred for high-current or high-ambient designs requiring superior thermal performance without layout change | Choose LP2998MRX/NOPB when junction temperature exceeds 110°C in SOIC-8 implementation |
Compared with TPS51100DGQR, LP2997MX/NOPB offers simpler layout, lower EMI, and integrated VREF but higher thermal dissipation; compared with LP2998MRX/NOPB, it shares identical functionality but trades thermal performance for lower cost and standard SOIC compatibility.
Availability
LP2997MX/NOPB is available at Aetrix Electronics and suitable for DDR-II memory termination, SSTL-18 interface design, and low-power embedded memory subsystems requiring stable component supply and long-term production continuity.
Supply support for LP2997MX/NOPB includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.
Manufacturer
Texas Instruments is a global semiconductor leader specializing in analog, embedded processing, and logic technologies, with over 50 years of innovation in power management and interface solutions.
The LP2997MX/NOPB belongs to TI's DDR termination regulator product line, engineered specifically for JEDEC-compliant DDR-II memory systems requiring precision VTT/VREF generation, low-noise linear regulation, and robust thermal management.
FAQ
What is the exact VTT output voltage tolerance of LP2997MX/NOPB at 125°C?
The LP2997MX/NOPB guarantees VTT output voltage within ±39 mV of nominal VDDQ/2 across 0°C to +125°C. At VDDQ = 1.8 V and IOUT = ±0.5 A, the datasheet specifies VTT = 0.878 V (min) to 0.940 V (max) - a total span of ±31 mV around 0.909 V typical. This meets JEDEC SSTL-18 VTT tolerance requirements.
Can LP2997MX/NOPB operate with VDDQ = 1.5 V?
No - LP2997MX/NOPB is specified only for VDDQ = 1.7 V to 1.9 V per Electrical Characteristics table. At VDDQ = 1.5 V, VREF would be ~0.75 V, falling outside JEDEC SSTL-18 compliance (0.85–0.95 V). The internal resistor divider is trimmed for 1.8 V nominal; operation below 1.7 V is not characterized or guaranteed.
Does LP2997MX/NOPB require an input capacitor on PVIN?
LP2997MX/NOPB does not require an input capacitor for stability, but TI recommends a 10–22 µF ceramic or aluminum electrolytic capacitor placed adjacent to the PVIN pin. This mitigates voltage droop during large load transients and improves transient response - especially critical in DDR-II applications with rapid current reversals.
How does VSENSE connection affect LP2997MX/NOPB load regulation?
When VSENSE is connected to the midpoint of the VTT distribution plane, LP2997MX/NOPB achieves <15 mV load regulation error across the entire bus. If VSENSE is tied directly to VTT pin (local sense), regulation degrades to ±39 mV due to IR drop - making remote sensing essential for multi-DIMM or long-PCB designs.
Is LP2997MX/NOPB pin-compatible with LP2997MR/NOPB?
Yes - LP2997MX/NOPB (SOIC-8) and LP2997MR/NOPB (SO PowerPAD-8) share identical pinout, function mapping, and electrical specifications. The only difference is thermal performance: MR uses exposed pad for θJA = 43°C/W, while MX uses standard SOIC with θJA = 151°C/W. PCB layout must accommodate different land patterns.
LP2997MX/NOPB Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Applications:
- DDR-II Terminator
- Current - Supply:
- 320µA
- Voltage - Supply:
- 2.2V ~ 5.5V
- Operating Temperature:
- 0°C ~ 125°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-SOIC
LP2997MX/NOPB FAQ
1.How can I place an order for LP2997MX/NOPB through Aetrix?
Please submit a Request for Quotation (RFQ) for LP2997MX/NOPB on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for LP2997MX/NOPB reliable?
The price and inventory of LP2997MX/NOPB are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LP2997MX/NOPB is usually 5 days.
3.What payment methods are accepted for LP2997MX/NOPB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LP2997MX/NOPB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LP2997MX/NOPB?
LP2997MX/NOPB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LP2997MX/NOPB order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for LP2997MX/NOPB?
For technical support, including LP2997MX/NOPB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LP2997MX/NOPB requirements.
6.How does Aetrix verify that LP2997MX/NOPB is sourced from the original manufacturer or authorized distributors?
All LP2997MX/NOPB products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that LP2997MX/NOPB meets industry standards.
7.What is the process for return or replacement of LP2997MX/NOPB?
All LP2997MX/NOPB units undergo pre-shipment inspection (PSI). If there is an issue with LP2997MX/NOPB, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The LP2997MX/NOPB part is unused and in its original packaging.
Return procedure for LP2997MX/NOPB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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