Texas Instruments OPA2846IDR

Overview

OPA2846IDR from Texas Instruments is a dual, voltage-feedback operational amplifier optimized for high-dynamic-range signal conditioning in wideband, low-noise applications. It delivers 1.2nV/√Hz input voltage noise, 300MHz closed-loop bandwidth at G = +10, 600V/µs slew rate, 1650MHz gain bandwidth product, and ±150µV input offset voltage - enabling precision differential receivers and ADC preamplifiers in ultrasound, VDSL, and security sensor front ends.

For engineers reviewing the OPA2846IDR datasheet, OPA2846IDR pinout, OPA2846IDR application, or OPA2846IDR equivalent, this page provides verified technical context, real-world design meaning of key specs, SO-8 package terminal roles, matched-channel performance implications, and validated alternative options for broadband transimpedance and high-SFDR receiver designs.

Technical Context

The OPA2846IDR employs a decompensated voltage-feedback architecture with minimum stable gain of +7V/V, enabling flat frequency response up to 100MHz at G = +10 while preserving 600V/µs slew rate and ultra-low distortion (–100dBc at 5MHz). Its dual-channel layout ensures tight gain and phase matching (<0.02° differential phase error), critical for I/Q channel amplification and differential ADC driving.

Each channel operates at 12.6mA quiescent current on ±5V supplies, delivering 1.65GHz GBP and 1.2nV/√Hz input voltage noise - making it suitable for photodiode transimpedance stages where noise gain stability and bandwidth optimization require external compensation networks (e.g., CF/CS tuning per Figure 6).

Key Specifications

Pinout & Package

OPA2846IDR is housed in an SO-8 (D) package with exposed pad for thermal enhancement, rated for –40°C to +85°C operation. Pin numbering follows standard SO-8 top-view orientation.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar wideband, low-noise op amp applications.

Compared with OPA2843IDR, OPA2846IDR offers 1.6× higher GBP and 1.7× lower input voltage noise - directly enabling 300MHz bandwidth at G = +10 and >10dB SFDR improvement in ADC preamp stages. Against OPA2846ID, the only distinction is packaging format; both share identical electrical behavior and SO-8 thermal performance.

Availability

OPA2846IDR is available at Aetrix Electronics and suitable for high-frequency ADC driving, photodiode transimpedance conversion, and VDSL line receiver applications requiring stable component supply, consistent parametric performance, and long-term industrial availability.

Supply support for OPA2846IDR 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

Texas Instruments is a global semiconductor leader specializing in analog and embedded processing technologies, with decades of expertise in high-performance op amp design and manufacturing.

The OPA2846IDR belongs to TI's OPAx846 family of decompensated, low-noise voltage-feedback op amps engineered specifically for wideband, high-SFDR signal chains in communications, test equipment, and medical imaging systems.

FAQ

What is the minimum stable gain for OPA2846IDR, and why does it matter?

The OPA2846IDR has a minimum stable gain of +7V/V due to its decompensated internal architecture. Operating below this gain risks peaking, ringing, or oscillation in closed-loop configurations. This constraint enables the device's 1650MHz GBP and 600V/µs slew rate - trade-offs that deliver superior bandwidth and linearity at moderate gains. For gains < +7, external compensation (e.g., CS/CF network per Figure 6) is required to maintain stability while preserving speed and noise performance. The OPA2846IDR datasheet specifies peaking of 3dB at G = +7, confirming marginal stability at the threshold.

Can OPA2846IDR be used in single-supply applications?

Yes, the OPA2846IDR supports single-supply operation when the input common-mode voltage remains within its specified range (±3.2V at ±5V supplies). To operate from a single +10V rail, bias inputs at +2.5V using precision resistive dividers and decouple with 0.1µF ceramics. Output swing will be limited to ~±3.3V into 100Ω, so ensure downstream circuitry accepts this range. The OPA2846IDR's rail-to-rail input capability and 110dB CMRR at DC make it viable for single-supply high-fidelity signal conditioning - but dual ±5V supplies are recommended for maximum dynamic range and distortion performance in ADC driver applications.

How does OPA2846IDR achieve –100dBc harmonic distortion at 5MHz?

The OPA2846IDR achieves –100dBc 2nd-harmonic distortion at 5MHz through a combination of ultra-low input voltage noise (1.2nV/√Hz), high slew rate (600V/µs), and optimized output stage linearity - all enabled by its decompensated voltage-feedback topology. This performance is measured under specific conditions: G = +10, VO = 2VPP differential, RL = 500Ω, and TA = 25°C. At lower loads (e.g., 100Ω), distortion degrades to –76dBc due to increased output current demand. The OPA2846IDR's matched dual channels further suppress even-order harmonics in differential configurations, making it ideal for high-SFDR receiver designs where distortion cancellation is critical.

What is the role of the exposed pad on the OPA2846IDR SO-8 package?

The exposed thermal pad on the OPA2846IDR's SO-8 (D) package must be soldered to a PCB copper pour connected to V− (pin 1) for optimal thermal performance. With θJA = 125°C/W, the pad reduces junction-to-board thermal resistance by ~30%, preventing thermal runaway during sustained 25mA total quiescent current operation. TI recommends a 6×6 array of 0.3mm thermal vias beneath the pad, filled or capped, and connected to an internal ground or negative supply plane. Failure to thermally connect the pad may cause junction temperatures to exceed +150°C at ambient +85°C - triggering permanent parametric shift or failure. The OPA2846IDR's absolute max junction temperature is +150°C, and thermal derating begins above +125°C.

Is OPA2846IDR pin-compatible with other dual op amps in SO-8 packages?

No, the OPA2846IDR is not pin-compatible with generic dual op amps (e.g., LM358, TL072, or OPA2350) due to its unique SO-8 pinout: V− (1), +In A (2), −In A (3), Out A (4), Out B (5), −In B (6), +In B (7), V+ (8). Standard dual op amps place V+ at pin 8 and V− at pin 4, with outputs at pins 1 and 7 - a completely different mapping. Interchanging OPA2846IDR with non-matched devices will cause immediate power rail shorting or signal inversion. Always verify pin functions against the OPA2846IDR datasheet (SBOS274C, page 2) before board layout or replacement. The OPA2846IDR shares pinout only with other members of the OPA2846 family (e.g., OPA2846ID).