Texas Instruments OPA1642AIDGKT

Overview

OPA1642AIDGKT from Texas Instruments is a dual-channel, JFET-input audio operational amplifier optimized for high-fidelity signal conditioning in professional and consumer audio systems. It delivers 5.1 nV/√Hz input voltage noise, 0.00005% THD+N at 1 kHz, 20 V/μs slew rate, ±2.25 V to ±18 V dual-supply operation, and rail-to-rail output swing - enabling low-distortion amplification in microphone preamps, line drivers, and active filters.

For engineers reviewing the OPA1642AIDGKT datasheet, OPA1642AIDGKT pinout, OPA1642AIDGKT application, or OPA1642AIDGKT equivalent, key selection criteria include its JFET-input bias current (±2 pA), channel separation (–126 dB at 1 kHz), wide common-mode range ((V–)–0.1 V to (V+)–3.5 V), EMI rejection ratio (86.8 dB at 2.4 GHz), and thermal performance in the VSSOP-8 package (R_θJA = 180 °C/W).

Technical Context

The OPA1642AIDGKT employs a true JFET-input stage with extremely stable input capacitance and no phase reversal - critical for maintaining signal integrity during overdrive in noninverting configurations. Its rail-to-rail output stage supports full-swing operation into 2-kΩ loads while sustaining ultralow distortion across ±2.25 V to ±18 V supply rails.

Internally, the device features completely independent channel circuitry to minimize crosstalk, and integrated output current limiting (±30 mA to ±36 mA) for short-circuit protection. It achieves unity-gain stability without external compensation and maintains >120 dB open-loop gain (A_OL) under 2-kΩ load conditions.

Key Specifications

Pinout & Package

VSSOP-8 (DGK) package: 3.00 mm × 3.00 mm body, 0.65 mm lead pitch, exposed thermal pad (not electrically connected), RoHS-compliant.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual-channel JFET-input audio amplifier applications.

Compared with OPA2134PA and NE5532DR, the OPA1642AIDGKT provides superior noise performance, guaranteed phase reversal immunity, and industry-leading EMI rejection - making it the preferred choice for new high-fidelity audio designs targeting THD+N < 0.0001% and operation in mixed-signal environments.

Availability

OPA1642AIDGKT is available at Aetrix Electronics and suitable for professional audio equipment, broadcast studio gear, and high-end A/V receivers requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for OPA1642AIDGKT 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 audio signal chain solutions.

The OPA1642AIDGKT belongs to TI's SoundPlus™ audio op amp product line, engineered specifically for ultralow distortion, low-noise, and high-EMI-immunity audio signal conditioning in professional and consumer equipment.

FAQ

What is the maximum capacitive load the OPA1642AIDGKT can drive without instability?

The OPA1642AIDGKT remains stable driving up to 100 pF with appropriate output series resistance (e.g., 24 Ω). Figure 19 in the datasheet shows overshoot remains below 10% at 100-pF load with R_OUT = 24 Ω. For larger loads, external compensation or isolation resistors are required. This behavior is confirmed across the full ±2.25 V to ±18 V supply range and –40°C to +85°C operating temperature.

Does the OPA1642AIDGKT support single-supply operation?

Yes, the OPA1642AIDGKT operates from a single 4.5 V to 36 V supply, with input common-mode range extending to (V–)–0.1 V and output swing within 350 mV of each rail at 2-kΩ load. Its rail-to-rail output and JFET input enable true single-supply audio buffering and filtering - verified in Section 6.3 and Figure 3 of the SBOS484D datasheet.

How does the OPA1642AIDGKT handle input overvoltage beyond the common-mode range?

The OPA1642AIDGKT incorporates internal phase-reversal protection: when input voltage exceeds the linear common-mode range, the output saturates at the nearest rail instead of inverting polarity. This behavior is documented in Section 7.3.1 and Figure 29 of SBOS484D, ensuring predictable clipping in noninverting amplifier configurations.

What is the thermal resistance of the OPA1642AIDGKT in its VSSOP-8 package?

The OPA1642AIDGKT in DGK (VSSOP-8) package has a junction-to-ambient thermal resistance (R_θJA) of 180 °C/W, junction-to-board (R_θJB) of 130 °C/W, and junction-to-case (top) of 55 °C/W - values specified in Table 6-4 of SBOS484D. These metrics assume standard JEDEC 2-layer board layout with 1-in² copper pour under the exposed pad.

Is the OPA1642AIDGKT pin-compatible with other members of the OPA164x family?

No - the OPA1642AIDGKT (dual, VSSOP-8) uses a different pinout than the OPA1641 (single, VSSOP-8) and OPA1644 (quad, TSSOP-14). Pin mapping is explicitly defined in Section 5 of SBOS484D: OPA1642AIDGKT assigns Pins 1/7 to OUT A/B, Pins 2/6 to –IN A/B, Pins 3/5 to +IN A/B, and Pins 4/8 to V–/V+, respectively.