Texas Instruments LP2995MX/NOPB

Overview

LP2995MX/NOPB from Texas Instruments is a linear DDR termination regulator designed for SSTL-2 and SSTL-3 bus termination in DDR-SDRAM systems. It sources and sinks up to ±1.5 A continuous current, regulates VTT to VDDQ/2 (e.g., 1.25 V at VDDQ = 2.5 V), and provides a buffered VREF output with ±15 mV offset tolerance for chipset reference.

For engineers reviewing the LP2995MX/NOPB datasheet, LP2995MX/NOPB pinout, LP2995MX/NOPB application, or LP2995MX/NOPB equivalent, this device is selected for precise DDR memory bus termination where tight VTT–VREF tracking, fast transient response to ±3 A peaks, and low external component count are critical in high-speed motherboard and DIMM designs.

Technical Context

The LP2995MX/NOPB integrates two high-speed operational amplifiers: one controls the VTT output stage to prevent shoot-through while delivering bidirectional current, and the other buffers the internal VDDQ/2 reference onto VREF. Its feedback architecture uses VSENSE for remote load regulation, enabling accurate VTT control at the center of long termination buses.

It operates with AVIN and PVIN tied to the same 2.2–5.5 V rail, accepts VDDQ as a remote-sense input to set the reference scaling, and supports configurable reference voltage via external resistors on VDDQ or VSENSE-enabling adaptation to SSTL-2 (0.5×), SSTL-3 (0.45×), or custom termination ratios.

Key Specifications

Pinout & Package

LP2995MX/NOPB is packaged in an 8-pin SOIC (D) with exposed thermal pad not connected internally (PowerPAD variant uses separate package). Pin 1 is marked by notch or bevel; pins 1–4 and 5–8 run counter-clockwise from top-left corner.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar DDR termination regulator applications.

Compared with LP2995MR/NOPB, LP2995MX/NOPB offers lower cost and simpler layout but requires careful thermal design above 0.8 A continuous load; versus TPS51100DGQR, it delivers lower noise and zero inductor-related EMI, making it preferred for noise-sensitive server memory subsystems.

Availability

LP2995MX/NOPB is available at Aetrix Electronics and suitable for DDR-SDRAM termination, SSTL-2 interface design, and chipset reference distribution requiring stable component supply across industrial, computing, and embedded memory applications.

Supply support for LP2995MX/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 U.S.-based semiconductor company specializing in analog, embedded processing, and logic solutions, with leadership in power management and interface ICs.

The LP2995MX/NOPB belongs to TI's DDR termination regulator product line, engineered specifically to meet JEDEC SSTL-2/SSTL-3 requirements for high-speed memory subsystems in servers, workstations, and industrial controllers.

FAQ

What is the primary function of the LP2995MX/NOPB in a DDR-SDRAM system?

The LP2995MX/NOPB serves as a linear bus termination regulator that generates and maintains the VTT termination voltage equal to VDDQ/2 (e.g., 1.25 V for 2.5 V DDR) and provides a buffered VREF reference. It sources and sinks bidirectional current up to ±1.5 A to stabilize the memory bus during high-speed data transitions, directly supporting JEDEC SSTL-2 and SSTL-3 compliance in systems using LP2995MX/NOPB.

Can the LP2995MX/NOPB be used for SSTL-3 applications requiring VTT = 1.5 V?

Yes - the LP2995MX/NOPB supports SSTL-3 by adding an external resistor in series with the VDDQ pin to adjust the internal resistor divider ratio from 0.5× to 0.45×, yielding VTT ≈ 1.485 V when VDDQ = 3.3 V. This configuration is documented in the LP2995MX/NOPB datasheet Figure 18 and requires no changes to the LP2995MX/NOPB's internal circuitry.

How does the VSENSE pin improve performance in motherboard layouts?

The VSENSE pin enables remote sensing by connecting to the midpoint of the VTT termination bus, compensating for IR voltage drop along long PCB traces. This ensures the LP2995MX/NOPB regulates VTT precisely at the point of load rather than at the regulator output, maintaining <±15 mV regulation accuracy across multi-DIMM configurations - a capability confirmed in LP2995MX/NOPB electrical characteristics testing.

What is the maximum continuous output current rating for the LP2995MX/NOPB in SOIC-8 package?

The LP2995MX/NOPB in SOIC-8 package supports ±1.5 A continuous output current under specified thermal conditions (TA ≤ 55°C, θJA = 151°C/W). At higher ambient temperatures or without airflow, derating is required per the thermal dissipation equations in the LP2995MX/NOPB datasheet to avoid exceeding 125°C junction temperature.

Is the LP2995MX/NOPB pin-compatible with other packages in the LP2995 family?

No - the LP2995MX/NOPB (SOIC-8) has a different pinout than the WQFN-16 (LP2995LQ/NOPB) and SO PowerPAD-8 (LP2995MR/NOPB) variants. While functional behavior is identical, pin assignments for AVIN, PVIN, VSENSE, and GND differ across packages; board redesign is required when substituting LP2995MX/NOPB for other LP2995 package options.