Analog Devices Inc. LTC6268IS6-10#TRMPBF

Overview

LTC6268IS6-10#TRMPBF from Analog Devices (formerly Linear Technology) is a single-channel, decompensated FET-input operational amplifier optimized for ultra-low input bias current (±3 fA typ. at 25°C), 0.45 pF common-mode input capacitance, and 4 GHz gain-bandwidth product. It operates from 3.1V to 5.25V, delivers rail-to-rail output swing, and features active shutdown - making it ideal for high-speed transimpedance amplifiers in photodiode-based optical sensing systems.

For engineers reviewing the LTC6268IS6-10#TRMPBF datasheet, LTC6268IS6-10#TRMPBF pinout, LTC6268IS6-10#TRMPBF application, or LTC6268IS6-10#TRMPBF equivalent, key selection criteria include femtoamp-level input bias stability over temperature, sub-0.5 pF input capacitance for TIA bandwidth optimization, gain-of-10 stability, and TSOT-23 package compatibility with space-constrained photonic front-ends.

Technical Context

The LTC6268IS6-10#TRMPBF employs a CMOS input buffer stage that bootstraps protection diodes to suppress leakage, enabling ±3 fA typical input bias current. Its complementary differential input pair covers the full –0.1 V to 4.5 V input voltage range while maintaining >64 dB CMRR across 0.1 Hz–100 MHz.

This op amp uses a cascode-output topology with common-emitter transistors (Q1/Q2) to achieve rail-to-rail output swing and +1500 V/µs / –1000 V/µs slew rate. It is gain-stable only at AV ≥ 10 and requires careful feedback compensation (e.g., CF ≥ CIN × GBW / RF) to avoid instability in transimpedance configurations.

Key Specifications

Pinout & Package

The LTC6268IS6-10#TRMPBF is housed in a 6-lead plastic TSOT-23 package (S6), with thermal pad exposed on bottom (not electrically connected). Pin 1 is marked by dot; pin numbering follows standard TSOT-23 convention (counterclockwise from mark).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar ultra-low-bias-current op amp applications.

Compared with ADA4530-1ARMZ and OPA810IDBVR, the LTC6268IS6-10#TRMPBF uniquely balances 4 GHz bandwidth, ±3 fA bias, 0.45 pF capacitance, and integrated shutdown - making it the only option for compact, battery-aware, >100 MHz optical front-ends demanding femtoamp fidelity.

Availability

LTC6268IS6-10#TRMPBF is available at Aetrix Electronics and suitable for photodiode transimpedance amplifiers, high-speed ADC drivers, and photomultiplier tube post-amplifiers requiring stable component supply across industrial temperature ranges and long production lifecycles.

Supply support for LTC6268IS6-10#TRMPBF 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 legacy of high-performance analog ICs for precision, speed, and low-noise applications.

The LTC6268-10 product line was designed specifically for ultra-low-leakage, high-bandwidth signal conditioning in optical sensing - targeting photodiode, SiPM, and PMT front-ends where femtoamp bias and sub-picofarad capacitance are non-negotiable.

FAQ

What is the minimum stable gain for LTC6268IS6-10#TRMPBF?

The LTC6268IS6-10#TRMPBF is decompensated and specified as gain-of-10 stable. It must be used with closed-loop gain ≥10 (AV ≥ 10) to ensure phase margin and prevent oscillation. Using it at unity gain or gain-of-2 will result in instability and peaking in frequency response.

Does LTC6268IS6-10#TRMPBF require external compensation in transimpedance amplifier circuits?

Yes - the LTC6268IS6-10#TRMPBF requires a small feedback capacitor (CF) in parallel with RF to stabilize the loop. For example, with RF = 20 kΩ and CIN = 1 pF, CF ≥ 60 fF is needed. The exact value depends on total input capacitance and desired damping factor, per the manufacturer's stability equations.

What is the maximum junction temperature and thermal resistance for LTC6268IS6-10#TRMPBF in TSOT-23?

The maximum junction temperature for LTC6268IS6-10#TRMPBF is 150°C. Its thermal resistance θJA is 192°C/W (measured with short PCB traces), meaning power dissipation >83 mW (16.5 mA × 5 V) requires careful thermal layout or derating above 25°C ambient to avoid exceeding TJMAX.

Can LTC6268IS6-10#TRMPBF operate with split supplies?

Yes - LTC6268IS6-10#TRMPBF supports split supplies as long as the total voltage between V+ and V– remains within 3.1 V to 5.25 V. For example, ±2.5 V (5 V total) is valid; however, input common-mode range remains referenced to V–, and output swing is rail-to-rail relative to V+ and V–.

How does the shutdown feature affect output state in LTC6268IS6-10#TRMPBF?

When SHDN is pulled low (≤0.75 V), the LTC6268IS6-10#TRMPBF enters high-impedance shutdown mode within 183 ns (tOFF), disabling output drive. The output floats - it is not clamped or pulled to any rail. External pull-up/down resistors may be needed to define idle state in system-level logic.