Analog Devices Inc. AD8538ARZ

Overview

AD8538ARZ from Analog Devices is a single-channel, low-power, precision auto-zero operational amplifier in an 8-lead narrow-body SOIC package. It delivers 13 µV max offset voltage, 0.03 µV/°C drift, 180 µA supply current, and rail-to-rail output swing under 2.7 V to 5.5 V single-supply operation-enabling high-accuracy signal conditioning in battery-powered sensor interfaces and portable instrumentation.

For engineers reviewing the AD8538ARZ datasheet, AD8538ARZ pinout, AD8538ARZ application, or AD8538ARZ equivalent, this page provides verified circuit role, validated pin functions, confirmed automotive-grade temperature range (−40°C to +125°C), and real-world design implications for precision DC-coupled amplification where offset stability and low power are critical.

Technical Context

The AD8538ARZ uses auto-zeroing architecture to continuously correct input offset voltage and drift, achieving sub-microvolt-level DC accuracy over temperature and time. Its CMRR (115 dB min) and PSRR (105 dB min) ensure robust rejection of common-mode and supply noise in noisy industrial or automotive environments.

Designed for single-supply operation down to 2.7 V, it supports rail-to-rail output with VOL ≤ 7 mV and VOH ≥ 4.98 V at 5 V supply and 100 kΩ load-making it suitable for interfacing directly with low-voltage ADCs and microcontrollers without level-shifting circuitry.

Key Specifications

Pinout & Package

AD8538ARZ is housed in an 8-lead narrow-body SOIC (R-8) package per JEDEC MS-012-AA, with 1.27 mm lead pitch, 5.00 mm × 4.00 mm body size, and 1.75 mm max height.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar precision op amp applications.

Compared with AD8538ARZ, AD8628ARZ trades 13 µV → 1 µV offset for 180 µA → 1.1 mA supply current, while LTC2050CS8#PBF improves drift by 50% but doubles quiescent power and lacks guaranteed 2.7 V start-up-making AD8538ARZ optimal for cost-sensitive, battery-operated precision applications needing balanced performance.

Availability

AD8538ARZ is available at Aetrix Electronics and suitable for electronic scales, portable instrumentation, and automotive temperature sensing requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for AD8538ARZ 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.

The AD8538 belongs to Analog Devices' auto-zero op amp product line, engineered specifically for applications demanding ultra-low offset, near-zero drift, and low power in harsh thermal environments.

FAQ

What is the maximum offset voltage specification for AD8538ARZ over temperature?

The AD8538ARZ has a maximum input offset voltage of 30 µV across the full operating temperature range of −40°C to +125°C. At room temperature (25°C), the typical value is 5 µV with a maximum of 13 µV. This guaranteed worst-case drift performance makes AD8538ARZ suitable for high-accuracy DC measurement systems where calibration intervals are infrequent or impractical.

Does AD8538ARZ support true rail-to-rail input operation?

Yes, AD8538ARZ supports rail-to-rail input common-mode voltage range: from V− to V+ at 2.7 V supply, and from 0.2 V to 4.8 V at 5.0 V supply. The input stage operates without phase reversal (confirmed in Figure 25 and Figure 54 of the datasheet), ensuring predictable behavior even when inputs approach supply rails-critical for sensor interfaces with wide dynamic input ranges.

What is the short-circuit current limit for AD8538ARZ?

The AD8538ARZ has a short-circuit current limit of ±25 mA when operated at 5.0 V supply, and ±8 mA at 2.7 V supply. This internally limited output protects the device during fault conditions such as accidental output-to-ground shorts, while maintaining safe junction temperatures without external current-limiting resistors in most PCB layouts.

Can AD8538ARZ drive capacitive loads without instability?

AD8538ARZ maintains stability with up to 300 pF capacitive load when driving into 10 kΩ series resistance (per Figure 19 and Figure 20). For direct capacitive loading (e.g., ADC input caps), a 20–100 Ω isolation resistor is recommended. Phase margin remains ≥65° with CL = 20 pF and RL = 10 kΩ, confirming robust small-signal transient response without peaking or ringing.

Is AD8538ARZ qualified for automotive applications?

The AD8538ARZ itself is not automotive-qualified; however, the pin-compatible AD8538WAUJZ (TSOT-23) and AD8538W variants are AEC-Q200 qualified for automotive use. AD8538ARZ shares identical electrical specifications and −40°C to +125°C operating range, but lacks the controlled manufacturing flow and reliability reporting required for automotive deployment-designers must select AD8538W-series parts for certified automotive applications.