NXP Semiconductors NE1617ADS,118

Overview

NE1617ADS,118 from NXP Semiconductors is a dual-channel SMBus temperature monitor IC that measures local (on-die) and remote (diode-connected transistor) temperatures with ±2 °C accuracy at 60–100 °C for local sensing and ±3 °C over the same range for remote sensing. It features programmable over/undertemperature alarms, one-shot conversion trigger, and hardware/software standby modes - deployed in microprocessor thermal management systems including desktop and notebook computers.

For engineers reviewing the NE1617ADS,118 datasheet, NE1617ADS,118 pinout, NE1617ADS,118 application, or NE1617ADS,118 equivalent, key selection criteria include its 16-pin SSOP package, SMBus 2-wire interface (≤100 kHz), 3–5.5 V supply range, 70 μA operating current, and support for Intel Pentium III–compatible thermal diodes.

Technical Context

The NE1617ADS,118 integrates an analog multiplexer, integrating A-to-D converter, and SMBus interface to perform simultaneous local and remote temperature conversions every 125 ms to 16 s (programmable via conversion rate register). Its measurement method relies on ΔV_BE across two precisely controlled current sources (10 μA / 100 μA) applied to the remote diode, eliminating dependence on saturation current and enabling calibration-free operation.

It implements full SMBus protocol compliance including Write Byte, Read Byte, Send Byte (for one-shot command), and Receive Byte, with Alert interrupt signaling via open-drain ALERT pin. Addressing supports nine unique slave addresses via ADD0/ADD1 pins configured as LOW, HIGH, or floating - enabling multi-device thermal monitoring on a single bus without conflict.

Key Specifications

Pinout & Package

NE1617ADS,118 is housed in a 16-lead plastic shrink small outline package (SSOP16, SOT519-1), 3.9 mm body width, 0.635 mm lead pitch - suitable for high-density PCB layouts in computing and telecom equipment.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar temperature monitor applications.

Compared with MAX1617AESA+ and ADM1021ARQZ, NE1617ADS,118 uniquely combines hardware STBY pin control, lower 3 μA standby current, and explicit Intel PIII diode compatibility - making it optimal for new x86 client platform designs prioritizing power efficiency and thermal precision.

Availability

NE1617ADS,118 is available at Aetrix Electronics and suitable for desktop computers, notebook computers, and industrial controllers requiring stable component supply, long-term lifecycle support, and RoHS-compliant sourcing.

Supply support for NE1617ADS,118 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 NE1617ADS,118 belongs to NXP's precision analog sensor product line, designed specifically for microprocessor thermal management in computing and embedded systems - emphasizing SMBus interoperability, low-power operation, and factory-trimmed accuracy.

FAQ

What is the remote temperature sensing accuracy of NE1617ADS,118 across its full operating range?

The NE1617ADS,118 achieves ±3 °C accuracy for remote temperature sensing at 60–100 °C and ±5 °C over the full −40 °C to +125 °C range. This specification applies to diode-connected transistors such as 2N3904/2N3906 or Intel Pentium III substrate diodes, and assumes proper external filtering (2200 pF capacitor between D+ and D−) and ideality factor matching (n ≈ 1.008).

How does the NE1617ADS,118 enter and exit standby mode?

The NE1617ADS,118 supports two independent standby entry methods: hardware standby (pull STBY pin LOW) and software standby (set bit 6 of the configuration register via SMBus). In hardware standby, ADC conversion is fully inhibited and one-shot commands are ignored; in software standby, one-shot commands still initiate a single conversion. Exit occurs automatically when STBY returns HIGH or the RUN/STOP bit is cleared.

Which SMBus protocols does NE1617ADS,118 support and how is the one-shot command executed?

The NE1617ADS,118 supports four standard SMBus protocols: Write Byte, Read Byte, Send Byte, and Receive Byte. The one-shot command is issued using the Send Byte protocol with command byte 0Fh (OSHT), which immediately triggers a full local and remote temperature conversion cycle - regardless of the current auto-conversion rate setting.

What happens if the remote diode connection fails on NE1617ADS,118, and how is it reported?

If the remote diode is disconnected (OPEN) or shorted between D+ and D−, the NE1617ADS,118 detects the fault during conversion and sets the OPEN flag (bit 2) in the status register. Concurrently, the ALERT pin is driven LOW, and the remote temperature register (RET) returns 127 °C. The fault condition persists until the physical connection is restored and the status register is read.

Can NE1617ADS,118 be used with NPN transistors as the remote sensor, and what is the correct connection?

Yes, NE1617ADS,118 supports NPN transistors as remote sensors. For an NPN device like the 2N3904, connect the base and collector to D+, and the emitter to D−. This configuration ensures proper forward biasing under the NE1617ADS,118's 10 μA/100 μA current sources and maintains compatibility with the ΔV_BE measurement algorithm.