Analog Devices Inc. LTC6269IDD#PBF

Overview

LTC6269IDD#PBF from Analog Devices (formerly Linear Technology) is a dual-channel, 500MHz FET-input operational amplifier optimized for ultra-low input bias current (±3fA typ. at 25°C), low input capacitance (450fF common-mode), and high-speed transimpedance amplifier (TIA) applications. It operates from 3.1V to 5.25V, delivers rail-to-rail output swing, and features shutdown control - making it ideal for photodiode amplification in optical sensing, precision CCD output buffering, and low-noise SAR ADC driving.

For engineers reviewing the LTC6269IDD#PBF datasheet, LTC6269IDD#PBF pinout, LTC6269IDD#PBF application, or LTC6269IDD#PBF equivalent, key selection criteria include confirmed fA-level input bias current, validated 350MHz –3dB bandwidth at unity gain, guaranteed operation over –40°C to 85°C, and compatibility with 10-lead 3mm × 3mm DFN packaging requiring exposed pad soldering to V–.

Technical Context

The LTC6269IDD#PBF implements a complementary CMOS input stage with bootstrapped ESD protection, enabling stable ultra-low I_B across its full input common-mode range (0V to 2.8V on 3.3V supply). Its architecture separates differential amplification into two overlapping ranges to maintain low distortion and high CMRR (>70dB) up to 10MHz.

It integrates active shutdown logic with 0.75V/1.5V thresholds, delivering <1µA shutdown current per amplifier and sub-700ns turn-on/off timing. The output stage uses a common-emitter topology to achieve rail-to-rail swing with 400V/µs slew rate and 135mA short-circuit capability while maintaining 4.3nV/√Hz voltage noise at 1MHz.

Key Specifications

Pinout & Package

The LTC6269IDD#PBF is housed in a 10-lead, 3mm × 3mm plastic DFN package (DD) with exposed thermal pad connected to V–. The package requires soldering the exposed pad to a PCB copper area tied to V– for thermal and electrical performance.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual FET-input op amp applications.

Compared with ADA4817-2ARMZ and OPA2140IDGKR, the LTC6269IDD#PBF uniquely balances femtoamp input bias, 500MHz bandwidth, and dual-channel shutdown - making it the only option among the three for high-speed, ultra-low-current optical front-ends requiring thermal stability across –40°C to 85°C.

Availability

LTC6269IDD#PBF is available at Aetrix Electronics and suitable for optical sensing, precision data acquisition, and industrial imaging systems requiring stable component supply with traceable sourcing and long-term lifecycle support.

Supply support for LTC6269IDD#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, Inc. (acquired Linear Technology in 2017) is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors.

The LTC6269 belongs to Linear's ultra-low bias current op amp product line, engineered specifically for photonics, scientific instrumentation, and high-impedance sensor signal conditioning where femtoamp leakage and picofarad capacitance directly impact measurement fidelity.

FAQ

What is the maximum operating temperature range specified for the LTC6269IDD#PBF?

The LTC6269IDD#PBF is rated for operation from –40°C to +85°C, as confirmed in the "ORDER INFORMATION" table and electrical characteristics sections. This grade is designated by the "I" suffix in the part family and is distinct from the H-grade (–40°C to 125°C) variant LTC6269HDD#PBF. Thermal derating is not required within this range when the exposed pad is properly soldered to a V–-referenced copper plane.

Does the LTC6269IDD#PBF support rail-to-rail input voltage range?

No, the LTC6269IDD#PBF does not support rail-to-rail input. Its input common-mode voltage range is specified as 0V to 2.8V on a 3.3V supply and 0V to 4.5V on a 5V supply - i.e., up to 0.5V below V+. This limitation is inherent to its CMOS input stage architecture and is explicitly stated in the "Input Voltage Range (IVR)" parameter (guaranteed by CMRR). Input voltages exceeding these limits may degrade CMRR or cause increased bias current.

How is the exposed thermal pad on the LTC6269IDD#PBF package connected?

The exposed pad (Pin 11) of the LTC6269IDD#PBF is internally connected to V– and must be soldered to a PCB copper area tied to the V– net. This connection is mandatory for both thermal dissipation (θ_JA = 43°C/W) and electrical stability. Leaving the pad floating or connecting it to ground (if V– ≠ GND) violates the Absolute Maximum Ratings and risks parametric shift or latch-up under transient conditions.

Can the LTC6269IDD#PBF be used in single-supply 3.3V applications?

Yes, the LTC6269IDD#PBF is fully specified for 3.3V operation (V+ = 3.3V, V– = 0V), with all key parameters - including 350MHz –3dB bandwidth, ±3fA input bias current, and 4.3nV/√Hz voltage noise - validated at this supply. The 3.3V Electrical Characteristics table confirms performance across the full –40°C to 85°C range, and the input voltage range (0V to 2.8V) accommodates typical single-ended sensor interfaces referenced to mid-supply.

What is the function of the SDA and SDB pins on the LTC6269IDD#PBF?

SDA and SDB are independent active-low shutdown control inputs for Channel A and Channel B, respectively. Driving either pin below 0.75V disables its associated amplifier channel, reducing quiescent current to ≤0.8mA per channel. Leaving either pin unconnected enables that channel by default. This dual-control capability allows asymmetric power management - for example, keeping Channel A active for continuous monitoring while cycling Channel B for burst-mode signal acquisition.