Texas Instruments OPA704NA/3K

Overview

OPA704NA/3K from Texas Instruments is a single-channel, rail-to-rail input/output CMOS operational amplifier optimized for non-inverting gains ≥5. It delivers 3MHz gain-bandwidth product, 3V/µs slew rate, 160µA quiescent current, ±160µV input offset voltage, and operates from ±2V to ±6V (or 4V–12V single supply). It is used in precision transducer amplification and high-speed data acquisition front-ends where low power and stable high-gain performance are required.

For engineers reviewing the OPA704NA/3K datasheet, OPA704NA/3K pinout, OPA704NA/3K application, or OPA704NA/3K equivalent, this page provides verified package mapping (SOT23-5), confirmed pin functions, real-world application constraints (e.g., gain ≥5 requirement), thermal derating guidance (θ_JA = 200°C/W), and validated alternatives with documented performance trade-offs.

Technical Context

The OPA704NA/3K uses a complementary input stage enabling rail-to-rail common-mode input range extending 300mV beyond rails, and a class-AB output stage achieving 40mV rail-to-rail swing into 100kΩ. Its internal compensation is optimized for closed-loop gains of 5 or greater-unity-gain configurations risk instability without external compensation.

It features ultra-low input bias current (±1pA typ), 90dB full-scale CMRR, and 45nV/√Hz input voltage noise density at 1kHz. The device is fully specified over –40°C to +85°C and supports capacitive loads up to 1000pF when gain ≥5, with typical overshoot <5% at 100pF.

Key Specifications

Pinout & Package

SOT23-5 surface-mount package (5-pin, 2.9mm × 1.6mm footprint) with exposed pad for thermal enhancement; JEDEC MO-178AC compliant; moisture sensitivity level (MSL) 2 (260°C peak reflow, 1-year floor life).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar rail-to-rail operational amplifier applications.

Compared with OPA704NA/3K, OPA333AIDBVR offers superior long-term DC stability but sacrifices bandwidth and slew rate, while MCP6001UT-E/OT reduces cost and power but compromises input impedance and dynamic response-making OPA704NA/3K the optimal balance for G ≥ 5, low-power, rail-to-rail precision amplification.

Availability

OPA704NA/3K is available at Aetrix Electronics and suitable for portable instrumentation, automotive cabin sensors, and battery-powered data acquisition requiring stable component supply, consistent parametric performance, and long-term manufacturability.

Supply support for OPA704NA/3K 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 precision op amps and signal-chain solutions.

The OPA704NA/3K belongs to TI's precision rail-to-rail CMOS op amp family, designed specifically for low-power, high-accuracy signal conditioning in space-constrained and energy-sensitive applications such as portable medical devices and industrial IoT endpoints.

FAQ

What is the minimum recommended gain for stable operation of the OPA704NA/3K?

The OPA704NA/3K is internally compensated for stable operation at closed-loop gains of 5 or greater. Using it at unity gain or G = 2 risks peaking and oscillation due to reduced phase margin; TI explicitly recommends G ≥ 5 for unmodified use. For lower gains, external compensation (e.g., feedback capacitor) is required-refer to Figure 6 in SBOS180A for G = 5 implementation.

Can the OPA704NA/3K operate from a single 3.3V supply?

Yes, the OPA704NA/3K supports single-supply operation from 4V to 12V per datasheet specifications. While 3.3V is below the 4V minimum, operation at 3.3V is not guaranteed-parameters like output swing, CMRR, and GBW degrade outside spec. For true 3.3V systems, consider the OPA333 or TLV2461 as alternatives rated down to 1.8V.

What is the maximum capacitive load the OPA704NA/3K can drive without instability?

The OPA704NA/3K can drive up to 1000pF of pure capacitive load when configured at G ≥ 5, as confirmed by typical overshoot curves in SBOS180A. At G = 5, overshoot remains <5% even at 1000pF. Driving >100pF at unity gain requires series isolation resistor (10–20Ω) inside the feedback loop per Figure 5 to maintain stability.

Does the OPA704NA/3K have phase reversal protection when input voltages exceed the supply rails?

Yes-the OPA704NA/3K (like the OPA703) does not exhibit phase reversal when inputs exceed the supply rails, provided input current is limited to ≤10mA via series resistance. This behavior is confirmed in Figure 4 of SBOS180A and stems from its complementary input stage architecture, making it robust in overvoltage sensor interface scenarios.

What is the thermal resistance (θ_JA) of the OPA704NA/3K in its SOT23-5 package?

The OPA704NA/3K in SOT23-5 package has a junction-to-ambient thermal resistance (θ_JA) of 200°C/W, as specified in the Electrical Characteristics table on page 4 of SBOS180A. This value assumes standard JEDEC 2-layer board conditions; adding copper pour under the exposed pad reduces effective θ_JA by ~30–40°C/W in production layouts.