Texas Instruments THS4021CDGN

Overview

THS4021CDGN from Texas Instruments is a single-channel, ultra-low-noise (1.2 nV/√Hz), high-speed voltage-feedback operational amplifier optimized for gain ≥10 V/V stable operation. It delivers 290 MHz small-signal bandwidth, 470 V/µs slew rate, and 30 ns 0.1% settling time at G = 10, enabling precision signal conditioning in ultrasound front-ends and source measurement units.

For engineers reviewing the THS4021CDGN datasheet, THS4021CDGN pinout, THS4021CDGN application, or THS4021CDGN equivalent, this device is selected for low-distortion, wide-supply-range (±4.5 V to ±16 V), high-output-drive (200 mA) analog signal paths requiring sub-1.5 nV/√Hz noise and stable ≥10× gain configuration.

Technical Context

The THS4021CDGN employs a voltage-feedback architecture with internal compensation tailored for stability at closed-loop gains of 10 V/V and above - eliminating need for external compensation networks. Its offset nulling pins (Pins 1 & 8) enable precise DC calibration in high-gain sensor interfaces.

Designed for demanding AC performance, it achieves –68 dBc THD at 1 MHz (RL = 150 Ω), supports dual- or single-supply operation (±4.5 V to ±16 V or +9 V to +32 V), and maintains 1.2 nV/√Hz input voltage noise across >10 kHz - critical for preserving SNR in wideband medical and test equipment signal chains.

Key Specifications

Pinout & Package

THS4021CDGN is housed in an 8-pin HVSSOP (DGN) package with exposed thermal pad, optimized for high-frequency layout and thermal dissipation in compact PCB designs.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-speed, low-noise amplifier applications.

Compared with OPA656IDBVR and LMH6629MA/NOPB, THS4021CDGN uniquely balances ultra-low noise (1.2 nV/√Hz), high slew rate (470 V/µs), built-in offset nulling, and guaranteed ≥10 V/V stability - making it optimal for time-critical, high-fidelity analog signal chains where both AC fidelity and DC precision matter.

Availability

THS4021CDGN is available at Aetrix Electronics and suitable for ultrasound scanner front-ends, source measurement units, and power quality meters requiring stable component supply, long-term manufacturability, and consistent electrical performance across temperature.

Supply support for THS4021CDGN 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 precision signal-chain solutions.

The THS402x family was designed specifically for high-fidelity, wideband analog signal conditioning in medical imaging, automated test equipment, and precision instrumentation - prioritizing noise, speed, and stability in real-world layouts.

FAQ

What is the minimum stable gain for THS4021CDGN?

The THS4021CDGN is specified as stable at closed-loop gains ≥10 V/V and ≤–9 V/V. This means it can be used in non-inverting configurations with gain set to 10 or higher, or in inverting configurations with magnitude ≥9, without risk of oscillation - no external compensation is required under these conditions. This is confirmed in Section 3 of the SLOS265F datasheet.

Does THS4021CDGN support single-supply operation?

Yes, THS4021CDGN supports single-supply operation from +9 V to +32 V, as specified in Section 5.3 Recommended Operating Conditions. When used in single-supply mode, the input common-mode range extends to within 1.2 V of the negative rail (typically ground), and output swing reaches within ~1.5 V of each rail depending on load - enabling rail-to-rail input/output compatibility in many applications.

How do I use the NULL pins on THS4021CDGN?

The NULL pins (Pins 1 and 8) on THS4021CDGN are dedicated to offset voltage trimming. Connect a 10-kΩ potentiometer between Pin 1 and Pin 8, with its wiper tied to VCC– (Pin 4). Adjusting the potentiometer changes the internal bias current balance, reducing input offset voltage to typically <0.5 mV. This is especially valuable in DC-coupled, high-gain circuits like SMU sense amplifiers where offset drift affects measurement accuracy.

What is the thermal resistance (RθJA) of THS4021CDGN in the DGN package?

The junction-to-ambient thermal resistance (RθJA) for THS4021CDGN in the 8-pin HVSSOP (DGN) package is 58.4 °C/W, as listed in Table 5.4 Thermal Information. This value assumes standard JEDEC 2-layer board conditions (2 oz copper, 1 in² copper area). With typical 7.8 mA supply current at ±15 V, power dissipation is ~0.23 W, resulting in ~13.5 °C junction-to-ambient rise - well within safe limits for industrial ambient temperatures.

Can THS4021CDGN drive a 50 Ω load directly?

Yes, THS4021CDGN can drive a 50 Ω load directly: its output current capability is rated at 200 mA (typical) with ±15 V supplies, sufficient to deliver ±7.5 V into 50 Ω (15 Vpp). However, sustained high-current operation increases junction temperature - ensure adequate PCB copper area under the thermal pad and verify thermal performance per Figure 5-29 and Table 5.4. For continuous 50 Ω driving, derate output swing to ±6 V to maintain reliability.