Analog Devices Inc. LTC2055HDD#PBF

Overview

LTC2055HDD#PBF from Analog Devices (formerly Linear Technology) is a dual, micropower, zero-drift operational amplifier in an 8-lead 3mm × 3mm DFN package, rated for operation from –40°C to 125°C. It delivers 3μV max input offset voltage, 30nV/°C max drift, 130dB PSRR/CMRR, rail-to-rail output swing, and 500kHz gain-bandwidth - enabling precision DC-coupled signal conditioning in battery-powered instrumentation and industrial sensors.

For engineers reviewing the LTC2055HDD#PBF datasheet, LTC2055HDD#PBF pinout, LTC2055HDD#PBF application, or LTC2055HDD#PBF equivalent, key selection criteria include guaranteed high-temperature performance (–40°C to 125°C), ultra-low offset stability over temperature and supply, sub-150μA per amplifier supply current, and DFN package thermal performance with exposed V– pad.

Technical Context

The LTC2055HDD#PBF uses auto-zeroing architecture with a 1kHz internal clock to continuously correct input offset voltage and drift, achieving near-zero DC error across temperature and common-mode voltage. Its input stage supports rail-to-rail common-mode range (V– to V+ – 0.5V) and features 1pA typical input bias current at 25°C.

It operates from single 2.7V to 6V or dual ±2.5V supplies, delivering 140dB open-loop gain, 1.6μV_P-P (0.01Hz–10Hz) input-referred noise, and 0.5V/μs slew rate - optimized for low-frequency, high-accuracy applications where long-term DC stability is critical.

Key Specifications

Pinout & Package

Package: 8-lead (3mm × 3mm × 0.8mm) plastic DFN with underside metal pad internally connected to V–; JEDEC MO-229 variation, θ_JA = 160°C/W with minimal PCB copper.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LTC2055IDD#PBF, the LTC2055HDD#PBF provides guaranteed operation up to 125°C - essential for enclosed industrial enclosures - while matching all electrical specs. Versus AD8628ARZ, it offers dual-channel integration and 8× lower supply current, trading minor offset improvement for system-level integration and efficiency.

Availability

LTC2055HDD#PBF is available at Aetrix Electronics and suitable for thermocouple amplification, electronic scales, medical instrumentation, and low-side current sense applications requiring stable component supply across extended temperature ranges and long product lifecycles.

Supply support for LTC2055HDD#PBF 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 acquired Linear Technology in 2017 and maintains its precision analog portfolio with rigorous qualification and long-term product support.

The LTC2055HDD#PBF belongs to Linear's zero-drift op amp family, designed specifically for DC-accurate signal conditioning in harsh environments where temperature, aging, and supply variation degrade conventional amplifiers.

FAQ

What is the maximum operating temperature range for the LTC2055HDD#PBF?

The LTC2055HDD#PBF is specified for continuous operation from –40°C to +125°C. This extended temperature grade is validated per manufacturer test conditions and applies to all key DC parameters including input offset voltage, drift, PSRR, and CMRR. The DFN package's thermal design supports this rating with appropriate PCB copper area.

Does the LTC2055HDD#PBF require external capacitors for stability?

No, the LTC2055HDD#PBF is unity-gain stable and does not require external compensation capacitors. However, a 0.1μF ceramic capacitor placed close to the V+ and V– pins (within 2mm) is mandatory for supply decoupling to suppress 1kHz auto-zero clock feedthrough and ensure PSRR performance. Feedback networks may benefit from small (<10pF) capacitors to reduce high-frequency peaking.

How does the 1kHz auto-zero clock affect system-level noise performance?

The LTC2055HDD#PBF's 1kHz auto-zero clock introduces two forms of feedthrough: input-referred residue (<0.2μV_RMS) and output voltage spikes dependent on input impedance. At frequencies below 10Hz, noise remains dominated by 1.6μV_P-P (0.01–10Hz) broadband noise. For applications sensitive to 1kHz artifacts (e.g., lock-in amplifiers), adding a 100Hz low-pass filter after the amplifier effectively suppresses clock-related components without degrading DC accuracy.

Can the LTC2055HDD#PBF drive ADC inputs directly?

Yes - the LTC2055HDD#PBF's rail-to-rail output swing (within 10mV of rails at 5kΩ) and low output impedance (<1Ω) allow direct interface with SAR and sigma-delta ADCs. For 24-bit converters, place a 10Ω series resistor + 1nF capacitor at the output to limit charge kickback and prevent sampling errors. Avoid capacitive loads >100pF without isolation resistance to maintain stability.

Is the exposed metal pad on the bottom of the LTC2055HDD#PBF package electrically connected?

Yes - the underside metal pad of the LTC2055HDD#PBF's DFN package is internally connected to the V– pin (Pin 4). It must be soldered to a PCB copper pour tied to the system ground or negative supply plane. This connection is critical for thermal dissipation (reducing θ_JA from 160°C/W to ~60°C/W) and lowering output noise by providing a low-impedance return path for substrate currents.