NXP Semiconductors PCT2075D,118

Overview

PCT2075D,118 from NXP Semiconductors is an I²C-bus Fast-mode Plus digital temperature sensor and thermal watchdog IC with ±1 °C accuracy from −25 °C to +100 °C, 0.125 °C resolution, open-drain OS output, and programmable overtemperature thresholds. It serves as a system-level thermal monitor in embedded controllers and PC power management circuits.

For engineers reviewing the PCT2075D,118 datasheet, PCT2075D,118 pinout, PCT2075D,118 application, or PCT2075D,118 equivalent, key selection considerations include its SO8 package compatibility, 2.7–5.5 V supply range, 1 MHz I²C interface with SMBus timeout, 11-bit ADC architecture, and drop-in replaceability for LM75-series sensors in thermal shutdown designs.

Technical Context

The PCT2075D,118 integrates an on-chip band gap temperature sensor with a Sigma-Delta A-to-D converter delivering 11-bit two's complement output at 0.125 °C resolution. Its conversion cycle defaults to 100 ms (28 ms active, 72 ms idle), enabling low-power thermal monitoring without interrupting I²C communication.

It implements dual OS operating modes-comparator mode (thermostat behavior with hysteresis) and interrupt mode (latched fault signaling)-both configurable via the 8-bit Configuration register. The OS output is open-drain, polarity-selectable (HIGH/LOW), and fault-queue programmable (1/2/4/6 consecutive faults).

Key Specifications

Pinout & Package

Package: SO8 (plastic small outline, 8 leads, 3.9 mm body width, SOT96-1).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar digital temperature sensor and thermal watchdog applications.

Compared with LM75BIMM/NOPB, PCT2075D,118 delivers tighter accuracy and finer resolution for early thermal anomaly detection; compared with STTS751DT, it integrates actionable OS signaling but trades off absolute precision for system-level simplicity and lower BOM count.

Availability

PCT2075D,118 is available at Aetrix Electronics and suitable for server thermal management, industrial PLC cabinet monitoring, and automotive infotainment SoC thermal supervision requiring stable component supply across extended product lifecycles.

Supply support for PCT2075D,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 IoT applications.

The PCT2075D,118 belongs to NXP's precision analog sensor portfolio, designed specifically for high-reliability thermal monitoring in systems where accurate, programmable, and autonomous overtemperature response is critical.

FAQ

What is the default power-up configuration of the PCT2075D,118?

At power-up, the PCT2075D,118 initializes in normal operation mode with OS comparator mode enabled, OS active LOW, Tos = 80 °C, Thyst = 75 °C, and fault queue = 1. The Temp register holds 0 °C until the first 28 ms conversion completes. This allows immediate stand-alone thermostat functionality without host initialization - a key feature distinguishing PCT2075D,118 from earlier LM75 variants.

Does the PCT2075D,118 support multiple devices on the same I²C bus?

Yes, the PCT2075D,118 supports up to 27 devices on a single I²C bus using its three address pins (A0/A1/A2), each configurable as HIGH, LOW, or floating. This capability is implemented in hardware and does not require software arbitration. The PCT2075D,118 achieves this while maintaining full 1 MHz Fast-mode Plus compliance - a significant advantage over standard LM75 parts limited to 8 addresses.

How does the OS output behave in comparator versus interrupt mode on the PCT2075D,118?

In comparator mode, the PCT2075D,118 OS output activates when temperature exceeds Tos and deactivates only when it falls below Thyst - behaving like a hardware thermostat. In interrupt mode, OS activates on Tos crossing and remains latched until any register is read or shutdown mode is entered. This makes PCT2075D,118 suitable for both continuous thermal regulation (comparator) and event-driven fault logging (interrupt).

Can the PCT2075D,118 operate from a 1.8 V supply?

No, the PCT2075D,118 requires a minimum supply voltage of 2.7 V and operates up to 5.5 V. It is not rated for 1.8 V logic domains. For 1.8 V systems, designers must use level-shifting circuitry or select alternative sensors such as the STTS751DT, which explicitly supports 1.8 V operation - a key distinction that affects system-level power architecture decisions involving PCT2075D,118.

What is the purpose of the Tidle register in the PCT2075D,118?

The Tidle register in the PCT2075D,118 controls the interval between temperature conversions, ranging from 100 ms to 3.1 s in 100 ms increments. By extending idle time, the device reduces average current consumption - critical in always-on thermal supervision. For example, setting Tidle = 0x0A yields a 1 s sampling period, lowering power vs. default 100 ms, while still ensuring timely response to thermal events. This parameter is unique to PCT2075D,118 and absent in LM75-family predecessors.