Analog Devices Inc. AD590KH

Overview

AD590KH from Analog Devices is a 2-terminal integrated circuit temperature transducer that outputs a precise current of 1 μA/K proportional to absolute temperature (0 K to 423 K), calibrated to ±2.5°C at 25°C, with operating range from −55°C to +150°C and supply voltage compatibility from 4 V to 30 V - used in remote industrial temperature monitoring where long-line immunity and minimal support circuitry are required.

For engineers reviewing the AD590KH datasheet, AD590KH pinout, AD590KH application, or AD590KH equivalent, key selection considerations include its two-terminal current-output architecture, laser-trimmed calibration accuracy, high-impedance output for noise rejection over twisted-pair wiring, and compatibility with current-input ADCs or simple I-to-V conversion without linearization circuitry.

Technical Context

The AD590KH implements a PTAT (Proportional-To-Absolute-Temperature) current regulation architecture using matched silicon transistor pairs and laser-trimmed thin-film resistors to generate a stable 1 μA/K output. Its two-terminal configuration eliminates separate power and signal paths, enabling direct series connection in current-loop systems.

It operates as a high-impedance (>10 MΩ) current source across 4 V–30 V supply, delivering inherent rejection of supply drift (≤0.5 μA/V change from 4–5 V) and reverse-voltage tolerance up to −20 V. Electrical turn-on time is 20 μs, and effective shunt capacitance is 100 pF - supporting fast multiplexing via CMOS switches without signal degradation.

Key Specifications

Pinout & Package

AD590KH is supplied in a 3-pin TO-52 metal can package with two active terminals and one mechanical case pin. The device functions as a bidirectional 2-terminal current source: polarity determines forward conduction direction, but current magnitude remains strictly temperature-dependent.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM34DH and TSIC 506, the AD590KH provides superior noise immunity over distance, wider supply flexibility, and true absolute-temperature linearity - making it optimal for industrial analog signal chains where wiring constraints and supply instability dominate design trade-offs.

Availability

AD590KH is available at Aetrix Electronics and suitable for remote sensing, cold-junction compensation, and multiplexed temperature monitoring requiring stable component supply across extended temperature ranges and long cable runs.

Supply support for AD590KH 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 is a global semiconductor company specializing in high-performance analog, mixed-signal, and digital signal processing technologies for precision measurement and control.

The AD590 product line was engineered as monolithic 2-terminal current-output temperature transducers to replace discrete thermistor/RTD assemblies in industrial, automotive, and instrumentation systems demanding long-line reliability and minimal external components.

FAQ

What is the calibration accuracy specification for AD590KH?

The AD590KH is calibrated to ±2.5°C at 25°C (298.2 K), as specified in the AD590J/K family datasheet Rev. G. This represents the maximum deviation between indicated and actual temperature at that point, before any user trimming. Over the full −55°C to +150°C range, absolute error is ±5.5°C without external calibration adjustment - a value confirmed in Table 1 of the official Analog Devices datasheet.

Can AD590KH operate with a 3.3 V supply?

No, AD590KH requires a minimum supply voltage of 4 V to ensure proper regulation and specified output current accuracy. At 3.3 V, the device falls outside its guaranteed operating range and may exhibit nonlinear output or failure to regulate - per Absolute Maximum Ratings and Specifications sections in the AD590 Rev. G datasheet.

Is AD590KH pin-compatible with other AD590 variants like AD590J or AD590M?

Yes, AD590KH shares identical pinout and package (3-pin TO-52) with all AD590 variants including AD590J and AD590M. Differences lie solely in calibration grade and performance specifications - not physical layout or electrical interface - as confirmed in the Pin Configurations and Ordering Guide sections of the AD590 Rev. G datasheet.

How does AD590KH handle reverse polarity connection?

AD590KH withstands reverse voltage up to −20 V without damage, as stated in the Absolute Maximum Ratings table. During reverse bias, leakage current remains ≤10 pA at −10 V (doubling every 10°C), preserving device integrity - a key reliability feature for field-deployed sensors subject to wiring errors.

What is the thermal time constant of AD590KH in still air?

In still air without a heat sink, the AD590KH (TO-52 package) has an effective thermal time constant τ of 60 seconds, meaning it reaches 63.2% of a step temperature change within that interval - per Table 4 in the AD590 Rev. G datasheet. This value assumes standard mounting and accounts for both chip and case thermal mass.