Texas Instruments THS4601CDDARG3

Overview

THS4601CDDARG3 from Texas Instruments is a high-speed FET-input operational amplifier optimized for wideband transimpedance gain stages, photodiode amplification, and high-impedance signal conditioning. It delivers 180 MHz gain-bandwidth product, 100 V/µs slew rate, 5.4 nV/√Hz input voltage noise, ±15 V supply operation, and 100 pA maximum input bias current - enabling low-noise amplification of weak current signals in optical sensing and test equipment.

For engineers reviewing the THS4601CDDARG3 datasheet, THS4601CDDARG3 pinout, THS4601CDDARG3 application, or THS4601CDDARG3 equivalent, key selection criteria include transimpedance stability with capacitive sources (e.g., 18–220 pF photodiodes), output swing capability (±12.8 V @ ±15 V supplies), thermal performance (θ_JA = 66.6 °C/W with PowerPAD™), and unity-gain stability without external compensation.

Technical Context

The THS4601CDDARG3 employs a JFET-input stage to achieve ultra-low input bias current (≤100 pA) and high differential input impedance (10⁹ Ω || 3.5 pF), making it suitable for interfacing with high-impedance, low-current sources such as photodiodes. Its internal compensation ensures unity-gain stability while maintaining 180 MHz gain-bandwidth product across ±5 V to ±15 V supplies.

It supports wideband transimpedance configurations with feedback resistors up to 1 MΩ and source capacitances up to 220 pF - validated via measured −3 dB bandwidths (e.g., 3.3 MHz at 100 kΩ RF / 18 pF C_S). Output drive capability includes ±80 mA sourcing/sinking into 20 Ω and ±12.8 V swing into 1 kΩ at ±15 V supplies.

Key Specifications

Pinout & Package

THS4601CDDARG3 uses an 8-pin SOIC surface-mount package with PowerPAD™ (package designator 8DDA), featuring an exposed thermal pad for enhanced heat dissipation. The PowerPAD™ must be soldered to a PCB copper pour for optimal thermal performance (θ_JA = 66.6 °C/W).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-speed FET-input operational amplifier applications.

Compared with OPA655 and OPA637, THS4601CDDARG3 uniquely balances ±15 V operation, unity-gain stability, 180 MHz GBW, and sub-100 pA input bias - making it the only option among the three qualified for wideband photodiode amplification with high-RF feedback and capacitive source stabilization.

Availability

THS4601CDDARG3 is available at Aetrix Electronics and suitable for optical sensing, automated test equipment, and high-fidelity signal acquisition systems requiring stable component supply, long-term manufacturability, and traceable sourcing.

Supply support for THS4601CDDARG3 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 THS4601 series was designed specifically for wideband transimpedance amplification and high-impedance buffering in optical, test, and measurement applications - emphasizing low input bias current, high GBW, and robust thermal performance in SOIC PowerPAD™ packages.

FAQ

What is the maximum recommended feedback resistor value for stable transimpedance operation with THS4601CDDARG3?

The THS4601CDDARG3 supports stable transimpedance operation with feedback resistors up to 1 MΩ, as verified in TI's SLOS388B datasheet (Table 1). At 1 MΩ and 18 pF source capacitance, the measured −3 dB bandwidth is 1.1 MHz. Stability requires proper feedback capacitor selection (e.g., 0 pF for this case) and attention to parasitic capacitance at the inverting node. Always validate with lab measurements using the network analyzer interface method described in the datasheet.

Does THS4601CDDARG3 require external compensation for unity-gain operation?

No, THS4601CDDARG3 is internally compensated for unity-gain stability. The datasheet explicitly states "Unity Gain Stable" in its FEATURES section and confirms stable small-signal and large-signal frequency response at G = +1 in Figures 2 and 3. No external compensation components are needed for gains from +1 through +100, simplifying design and reducing board area.

What is the thermal performance advantage of the PowerPAD™ package in THS4601CDDARG3 versus standard SOIC?

The THS4601CDDARG3's SOIC-8 PowerPAD™ package achieves θ_JA = 66.6 °C/W, compared to 170 °C/W for the standard 8D SOIC (THS4601CD). This 61% reduction in junction-to-ambient thermal resistance allows sustained high-output-current operation - e.g., ±80 mA sourcing/sinking - without exceeding 150°C junction temperature, which is critical for reliability in continuous-duty test equipment.

Can THS4601CDDARG3 operate from a single +10 V supply?

Yes, THS4601CDDARG3 supports single-supply operation. With VS+ = +10 V and VS− = 0 V, the common-mode input range is +2.7 V to −2.0 V (min), and output swing is +2.9 V to −3.5 V (min) into 1 kΩ. Input biasing (e.g., IN+ tied to +2.5 V) and level-shifting networks are required to keep signals within valid ranges. Full ±15 V performance metrics do not apply under single-supply conditions.

How does THS4601CDDARG3 handle photodiode capacitance in transimpedance designs?

THS4601CDDARG3 is characterized for photodiode capacitances from 18 pF to 220 pF. Datasheet Table 1 shows validated −3 dB bandwidths (e.g., 3.3 MHz at 18 pF / 100 kΩ RF) using optimized feedback capacitance (0.6 pF). Its high GBW and low input capacitance (3.5 pF differential) minimize peaking and ensure stable, maximally flat response when CF is calculated per Equation 1 - enabling reliable design for diverse optical sensor interfaces.