Texas Instruments LP2996M/NOPB

Overview

LP2996M/NOPB from Texas Instruments is a linear DDR termination regulator designed for precise VTT generation in DDR1–DDR3L memory systems. It delivers ±1.5 A continuous and ±3 A peak sink/source current, regulates VTT = VDDQ/2 with ≤30 mV offset, and supports SSTL-2/3 and HSTL termination in industrial PC and FPGA applications.

For engineers reviewing the LP2996M/NOPB datasheet, LP2996M/NOPB pinout, LP2996M/NOPB application, or LP2996M/NOPB equivalent, this page provides verified electrical specs, thermal derating guidance, VSENSE remote sensing implementation, and STR-mode shutdown behavior critical for DDR bus stability and power sequencing compliance.

Technical Context

The LP2996M/NOPB implements a high-speed error amplifier driving a shoot-through-protected output stage to maintain tight regulation during fast DDR load transients. Its dual-rail architecture separates analog control (AVIN) from power delivery (PVIN), enabling optimized thermal performance and flexible supply partitioning.

VDDQ feeds an internal 50 kΩ/50 kΩ resistor divider to generate VREF = VDDQ/2, which is buffered and supplied to chipset/DIMM reference inputs. The VSENSE pin enables remote feedback at the bus midpoint to compensate for PCB IR drop, ensuring uniform termination voltage across long memory planes.

Key Specifications

Pinout & Package

LP2996M/NOPB is packaged in an 8-pin SOIC (D package) with exposed thermal pad (PowerPAD), measuring 4.90 mm × 3.90 mm. The PowerPAD must be soldered to a PCB ground plane for thermal management and EMI reduction.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LP2996N/NOPB, LP2996M/NOPB adds DDR3L compatibility and tighter VTT regulation, while TPS51200DRCT trades layout simplicity for higher efficiency in thermally constrained, high-current applications.

Availability

LP2996M/NOPB is available at Aetrix Electronics and suitable for DDR3L memory subsystems, FPGA I/O termination, and industrial medical PC designs requiring stable component supply with guaranteed long-term availability.

Supply support for LP2996M/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 power management ICs, with decades of DDR interface expertise and JEDEC-compliant design validation.

The LP2996M/NOPB belongs to TI's DDR termination regulator product line, engineered specifically for low-noise, high-transient-response VTT generation in memory-intensive computing and industrial systems.

FAQ

What is the minimum VDDQ voltage supported by the LP2996M/NOPB?

The LP2996M/NOPB supports a minimum VDDQ of 1.35 V, enabling full compliance with DDR3L JEDEC specifications. This is confirmed in the Electrical Characteristics table for DDR III operation, where VDDQ = 1.35 V yields VREF = 0.669–0.699 V and VTT = 0.656–0.698 V. The LP2996M/NOPB datasheet explicitly states this lower limit distinguishes it from the LP2996N/NOPB, which requires ≥1.8 V VDDQ.

How does the VSENSE pin improve termination accuracy in LP2996M/NOPB designs?

The VSENSE pin in the LP2996M/NOPB enables remote feedback by connecting to the midpoint of the DDR bus, compensating for IR voltage drop across PCB traces. This ensures VTT regulation accuracy remains within ±1% at all DIMM locations-not just at the regulator output-critical for high-speed signal integrity. The datasheet specifies that without VSENSE, VTT error increases significantly across long memory planes, and recommends placing a 0.1 µF ceramic capacitor near the VSENSE pin to suppress noise.

Can LP2996M/NOPB operate with separate AVIN and PVIN supplies?

Yes, the LP2996M/NOPB supports independent AVIN and PVIN rails per its Pin Functions description: AVIN powers internal control circuitry, while PVIN supplies the output stage. This split-rail architecture reduces thermal stress and improves efficiency-for example, AVIN can be set to 2.5 V for analog stability while PVIN is optimized at 3.3 V for higher output current capability. However, PVIN must never exceed AVIN to prevent damage, as specified in Absolute Maximum Ratings.

What happens to VREF during LP2996M/NOPB shutdown mode?

During shutdown (SD pin pulled low), the LP2996M/NOPB tri-states the VTT output but keeps VREF fully active and regulated at VDDQ/2. This behavior is essential for Suspend-to-RAM functionality, allowing the memory controller to retain reference voltage while terminating the bus in high-impedance state. The datasheet confirms VREF remains operational with 2.5 kΩ output impedance and continues supplying reference to chipset and DIMMs even when VTT is disabled.

Is thermal derating required for LP2996M/NOPB in SOIC package at full load?

Yes-thermal derating is mandatory for LP2996M/NOPB in SOIC (D package) at full ±1.5 A load. With RθJA = 119.5°C/W, even modest power dissipation (e.g., 1.5 A × 1.25 V dropout ≈ 1.875 W) raises junction temperature by ~224°C above ambient, far exceeding the 125°C max operating limit. The datasheet requires heatsinking, airflow, or reduced load current; use of the PowerPAD and PCB copper area is essential to achieve safe operation.