Analog Devices Inc. ADT7420UCPZ-RL7

Overview

ADT7420UCPZ-RL7 from Analog Devices is a high-accuracy, 16-bit digital I²C temperature sensor in a 4 mm × 4 mm LFCSP package, delivering ±0.25°C accuracy from −20°C to +105°C at 2.7 V–3.3 V, 0.0078°C resolution, and fast 6 ms first-conversion time on power-up-used for thermocouple cold-junction compensation and laser diode thermal control in industrial instrumentation.

For engineers reviewing the ADT7420UCPZ-RL7 datasheet, ADT7420UCPZ-RL7 pinout, ADT7420UCPZ-RL7 application, or ADT7420UCPZ-RL7 equivalent, key selection considerations include its programmable 13/16-bit ADC resolution, dual open-drain interrupt outputs (INT/CT), four I²C address options via A0/A1, ultralow 2.0 µA shutdown current at 3.3 V, and NIST-traceable calibration without user correction.

Technical Context

The ADT7420UCPZ-RL7 integrates a band gap reference, sigma-delta (Σ-Δ) modulator, and 16-bit ADC with internal oscillator-enabling 0.0078°C resolution in programmable 16-bit mode or 0.0625°C in default 13-bit mode. Its Σ-Δ architecture uses oversampling and digital filtering to achieve ±0.25°C accuracy across −20°C to +105°C without linearity correction.

It supports four operating modes: normal (240 ms conversion), one-shot (240 ms, then shutdown), 1 SPS (60 ms conversion + 940 ms idle), and shutdown (2.0 µA typical). INT and CT pins operate as programmable active-low/open-drain comparator or interrupt outputs, configurable via THIGH/TLOW/TCRIT/THYST registers and fault queue (1–4 consecutive faults).

Key Specifications

Pinout & Package

ADT7420UCPZ-RL7 is housed in a RoHS-compliant 16-lead, 4 mm × 4 mm LFCSP package with exposed pad (EP); EP may be left floating or connected to GND per datasheet guidance. Pins 5–8 and 13–16 are no-connect (NC) and must remain unconnected.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-accuracy digital temperature sensing applications.

Compared with MAX31875ASA+T and LM75BIMM/NOPB, the ADT7420UCPZ-RL7 uniquely combines NIST-traceable ±0.25°C accuracy, dual independent interrupt outputs (INT/CT), and configurable fault queue-making it the only option among the three qualified for thermocouple cold-junction compensation and laser diode thermal control in safety-critical systems.

Availability

ADT7420UCPZ-RL7 is available at Aetrix Electronics and suitable for industrial control and test, medical equipment, and environmental monitoring requiring stable component supply, long-lifecycle assurance, and full traceability from wafer to shipment.

Supply support for ADT7420UCPZ-RL7 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

Analog Devices, Inc. is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, headquartered in Norwood, MA, with design centers worldwide and ISO 9001-certified manufacturing.

The ADT7420UCPZ-RL7 belongs to Analog Devices' precision temperature sensor product line, engineered specifically for applications demanding metrology-grade accuracy, long-term stability, and autonomous thermal protection without host intervention.

FAQ

What is the guaranteed accuracy specification for ADT7420UCPZ-RL7 across its full operating range?

The ADT7420UCPZ-RL7 guarantees ±0.25°C accuracy from −20°C to +105°C at supply voltages of 2.7 V to 3.3 V. At wider ranges-such as −40°C to +105°C-it specifies ±0.35°C (at 3.0 V) and ±0.50°C (at 2.7 V–3.3 V). Accuracy degrades slightly above +125°C, reaching ±0.50°C at −40°C to +125°C and −0.85°C at +150°C under 4.5 V–5.5 V operation. These values are measured and specified per the Rev. A datasheet, Table 1.

Does ADT7420UCPZ-RL7 require external calibration or linearization in the host system?

No, the ADT7420UCPZ-RL7 does not require external calibration or linearization. Its internal band gap reference, sigma-delta ADC, and factory-trimmed temperature sensor deliver NIST-traceable ±0.25°C accuracy across −20°C to +105°C. The datasheet explicitly states "no temperature calibration/correction required by user" and "no linearity correction required," enabling plug-and-play integration into medical, industrial, and instrumentation systems without firmware compensation routines.

How many I²C addresses can be assigned to ADT7420UCPZ-RL7 on a shared bus?

The ADT7420UCPZ-RL7 supports four unique I²C slave addresses (0x48, 0x49, 0x4A, 0x4B) using the A0 and A1 pins. Each pin accepts logic high (VDD) or low (GND), forming a 2-bit address select code. This allows up to four ADT7420UCPZ-RL7 sensors to coexist on the same I²C bus without address conflict-ideal for multi-zone thermal monitoring in servers, power supplies, or industrial PLCs.

What is the function of the CT pin on ADT7420UCPZ-RL7, and how does it differ from the INT pin?

The CT (Critical Temperature) pin on ADT7420UCPZ-RL7 is an open-drain output that asserts only when temperature exceeds the programmable TCRIT threshold-designed for hardware-level safety shutdown. In contrast, the INT pin responds to both overtemperature (THIGH) and undertemperature (TLOW) conditions. CT operates independently, supports configurable polarity, and can be reset via register write or fault queue timeout-providing fail-safe thermal protection distinct from general-purpose alerting handled by INT.

Can ADT7420UCPZ-RL7 operate from a 5.0 V supply, and what impact does this have on accuracy?

Yes, ADT7420UCPZ-RL7 operates from 2.7 V to 5.5 V, including 5.0 V. However, accuracy at 5.0 V is reduced: ±0.50°C from −40°C to +105°C and ±0.66°C from −10°C to +105°C. The datasheet notes that "for higher accuracy at 5 V operation, contact Analog Devices, Inc."-indicating that optimal ±0.25°C performance is achieved at 2.7 V–3.3 V. Designers should use 3.3 V regulation where metrology-grade accuracy is mandatory.