Texas Instruments OPA842IDBVTG4

Overview

OPA842IDBVTG4 from Texas Instruments is a unity-gain stable, voltage-feedback operational amplifier optimized for high-speed, low-distortion signal conditioning. It delivers 400MHz unity-gain bandwidth, 2.6nV/√Hz input voltage noise, –93dBc third-harmonic distortion at 5MHz, and 22ns 0.01% settling time - enabling precision buffering of 14-bit, 10MSPS ADCs like the ADS850 in professional video and test instrumentation.

For engineers reviewing the OPA842IDBVTG4 datasheet, OPA842IDBVTG4 pinout, OPA842IDBVTG4 application, or OPA842IDBVTG4 equivalent, key selection criteria include its SOT-23-5 package compatibility with space-constrained layouts, ±5V supply operation, differential gain/phase error of 0.003%/0.008°, and verified performance driving capacitive loads up to 100pF with external series isolation.

Technical Context

The OPA842IDBVTG4 employs a two-stage voltage-feedback architecture that achieves unity-gain stability without external compensation while maintaining 200MHz gain-bandwidth product and 110dB open-loop gain. Its differential input stage enables precise bias current cancellation and supports dc-coupled configurations with matched impedance networks.

It operates across –40°C to +85°C with ±3.5V to ±6V supply range, delivers ±100mA output current, and maintains <0.001Ω closed-loop output impedance at 1kHz - critical for driving low-impedance video lines (75Ω) or ADC input capacitance without peaking or instability.

Key Specifications

Pinout & Package

SOT-23-5 package (DBV), 5-pin surface-mount, 2.9mm × 1.6mm footprint, 1.0mm height, thermal resistance θ_JA = 150°C/W.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-speed op amp applications.

Compared with OPA842IDBVTG4, OPA843IDBVT trades unity-gain stability for lower noise and higher bandwidth - making it unsuitable for G = +1 ADC buffers but superior in fixed-gain IF stages; OPA642U offers lower cost and proven reliability at the expense of dynamic range and speed.

Availability

OPA842IDBVTG4 is available at Aetrix Electronics and suitable for professional video line driving, high-resolution imaging front-ends, and test instrumentation signal conditioning requiring stable component supply and guaranteed long-term manufacturability.

Supply support for OPA842IDBVTG4 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 amps and data converter interface solutions.

The OPA842IDBVTG4 belongs to TI's precision high-speed op amp product line, engineered specifically for demanding applications requiring simultaneous wide bandwidth, ultra-low distortion, and dc accuracy - including professional video, medical imaging, and automated test equipment.

FAQ

What is the maximum capacitive load the OPA842IDBVTG4 can drive without external isolation?

The OPA842IDBVTG4 is not characterized for direct driving of capacitive loads >10pF without series isolation. Figure 15 in the SBOS267D datasheet recommends a 50Ω series resistor for 100pF loads. For stable operation into ADC inputs (typically 10–20pF), a 20–47Ω resistor is required to prevent peaking and ensure flat frequency response - verified in the OPA842IDBVTG4's typical characteristics at 5MHz.

Does the OPA842IDBVTG4 support single-supply operation?

No, the OPA842IDBVTG4 is specified only for dual-supply operation from ±3.5V to ±6V. Its input common-mode range extends to ±3.2V (at +25°C) and output swing is asymmetric (±3.2V positive, ±3.7V negative into high-Z), confirming it is not designed for rail-to-rail or single-supply use. Attempting single-supply operation violates absolute maximum ratings and degrades distortion and settling performance.

How does the OPA842IDBVTG4 achieve unity-gain stability with 400MHz bandwidth?

The OPA842IDBVTG4 achieves unity-gain stability through internal compensation of its two-stage voltage-feedback architecture - eliminating the need for external poles. This design maintains 400MHz unity-gain bandwidth while ensuring phase margin >45° across temperature and process corners, as validated in the SBOS267D stability testing (Figures 17–18). No external capacitor or resistor is required for G = +1 operation.

Can the OPA842IDBVTG4 replace the OPA642 in existing designs?

Yes, the OPA842IDBVTG4 is a functional upgrade to the OPA642 in most applications: it offers 400MHz vs 500MHz GBW, –93dBc vs –85dBc distortion at 5MHz, and 22ns vs 35ns settling. Pinout is identical in SO-8 (D) and SOT-23-5 (DBV) packages. However, verify power supply decoupling - OPA842IDBVTG4 requires tighter 0.1µF local ceramics due to higher slew rate (400V/µs) and wider bandwidth.

What is the recommended PCB layout practice for minimizing distortion in OPA842IDBVTG4 circuits?

Minimize distortion by using symmetric, short (<5mm) traces for IN+ and IN–, placing 0.1µF X7R ceramic decoupling caps ≤2mm from each supply pin, routing the output directly to the load with no stubs, and grounding the exposed pad (if present on DBV) to a solid thermal plane. Avoid routing digital traces near analog inputs - the OPA842IDBVTG4's 2.6nV/√Hz noise floor makes it sensitive to coupling-induced interference.