NXP Semiconductors NE57810S/G,518

Overview

NE57810S/G,518 from NXP Semiconductors is a linear DDR termination regulator designed to supply VTT (termination voltage) at precisely half the DDR memory supply voltage (VDD), supporting both DDR-I (2.5 V) and DDR-II (1.8 V) systems. It delivers ±3.5 A continuous output current, features internal overcurrent and overtemperature protection, and eliminates need for external inductors or switching FETs. It is used on DIMM modules and memory controllers in high-speed computing platforms.

For engineers reviewing the NE57810S/G,518 datasheet, NE57810S/G,518 pinout, NE57810S/G,518 application, or NE57810S/G,518 equivalent, key selection criteria include its VDD/2 tracking accuracy (±15 mV), fast transient response under ±3.5 A load steps, thermal robustness in SOT756 package, and support for external reference programming via ExtRefIn pin.

Technical Context

The NE57810S/G,518 implements a precision linear regulator architecture with an internal 100 kΩ/100 kΩ resistor divider between VDD and VSS, establishing the reference node for both VTT regulation and RefOut buffering. Its output stage sources and sinks current instantaneously-critical for DDR bus termination where aggregate bus state changes occur at 266 MHz.

It operates exclusively in linear mode: no switching components are required, and stability relies on ceramic + bulk capacitor combinations (e.g., 100 µF electrolytic + distributed 10 µF ceramics). The ExtRefIn pin enables externally set VTT voltages outside the VDD/2 default, allowing decoupling of termination power from memory VDD rails.

Key Specifications

Pinout & Package

The NE57810S/G,518 is housed in a thermally enhanced plastic single-ended surface-mounted SOT756 package (5 leads), featuring an exposed thermal pad electrically connected to VSS for improved heat dissipation. PCB layout must use the dedicated VSS pin-not the thermal pad-as the primary ground connection per device specifications.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS51100DGQ and ISL6537CRZ, the NE57810S/G,518 uniquely balances linear simplicity (no inductor/EMI concerns) with advanced flexibility (ExtRefIn, RefOut, ±3.5 A), making it optimal for DDR-I/II systems prioritizing signal integrity, layout density, and design reuse.

Availability

NE57810S/G,518 is available at Aetrix Electronics and suitable for desktop microcomputers, server memory subsystems, and embedded DDR memory interfaces requiring stable component supply, long-lifecycle availability, and JEDEC-compliant termination performance.

Supply support for NE57810S/G,518 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

NXP Semiconductors is a global semiconductor company headquartered in Eindhoven, Netherlands, specializing in secure connectivity solutions for automotive, industrial, and consumer applications.

The NE57810S/G,518 belongs to NXP's advanced memory interface power portfolio, engineered specifically to replace discrete termination networks in DDR-I and DDR-II systems while simplifying thermal and layout design.

FAQ

What is the primary function of the NE57810S/G,518 in a DDR memory system?

The NE57810S/G,518 serves as a linear DDR termination regulator that generates VTT-the termination voltage-at exactly half the DDR memory supply voltage (VDD). It sources and sinks up to ±3.5 A to maintain signal integrity on high-speed DDR-I and DDR-II buses, replacing discrete resistor networks and eliminating need for external inductors or switching FETs. Its design directly targets JEDEC-compliant termination requirements.

Can the NE57810S/G,518 operate with DDR-II memory running at 1.8 V VDD?

Yes, the NE57810S/G,518 is explicitly compatible with DDR-II systems operating at 1.8 V VDD. When VDD = 1.8 V, the internal divider sets VTT to 0.9 V (±15 mV), and the device delivers ±2.5 A maximum output current under this condition. This capability is confirmed in Table 5 of the datasheet and supports seamless migration from DDR-I (2.5 V) to DDR-II (1.8 V) platforms using the same NE57810S/G,518 footprint.

How does the ExtRefIn pin change the behavior of the NE57810S/G,518?

The ExtRefIn pin (Pin 4) allows the NE57810S/G,518 to generate a VTT voltage independent of VDD/2-enabling programmable termination such as 0.9 V for DDR-II even when VDD is derived from a different rail. When an external reference is applied, the internal 100 kΩ/100 kΩ divider is overridden, and VTT tracks ExtRefIn with ±15 mV accuracy. This feature supports power architecture optimization, like separating termination power from memory VDD to balance system-level load distribution.

What thermal design considerations apply to the NE57810S/G,518 in a real-world PCB layout?

The NE57810S/G,518 has a junction-to-ambient thermal resistance of 16.5 °C/W on a JEDEC 4-layer test board, but typical layouts achieve ~36.6 °C/W. To keep junction temperature ≤125 °C at 70 °C ambient and 1.5 W average dissipation, a minimum 225 mm² copper island (15 mm × 15 mm) is required. The thermal pad must be soldered to a solid VSS plane-but the VSS pin (Pin 3), not the pad, remains the designated ground reference per datasheet specification.

Is the RefOut pin of the NE57810S/G,518 buffered, and what is its drive capability?

Yes, the RefOut pin (Pin 5) is a buffered, low-impedance copy of the internal reference-either VDD/2 (when ExtRefIn is unconnected) or the applied ExtRefIn voltage. It can source or sink up to ±3 mA while maintaining ±15 mV accuracy, enabling direct connection to DDR memory VREF inputs or other analog control circuits without additional op-amps or level shifters. This eliminates external reference buffers in multi-IC memory subsystems.