Texas Instruments THS4509RGTR

Overview

THS4509RGTR from Texas Instruments is a wideband, low-noise, fully-differential amplifier optimized for 5-V data acquisition systems. It delivers 1.9 nV/√Hz input voltage noise, –75 dBc HD2 and –80 dBc HD3 at 100 MHz, 6600 V/μs slew rate, and operates with 3–5 V supply. It drives high-speed ADCs such as the ADS5500 at 125 MSPS in pulsed, high-linearity applications.

For engineers reviewing the THS4509RGTR datasheet, THS4509RGTR pinout, THS4509RGTR application, or THS4509RGTR equivalent, key selection criteria include differential output common-mode control accuracy (±3 mV offset), minimum stable gain of 2 V/V (6 dB), 1900 MHz small-signal bandwidth at G = 10 dB, and power-down capability reducing quiescent current to 0.65 mA.

Technical Context

The THS4509RGTR employs a fully-differential architecture with centered input common-mode range (1.1–3.9 V at 5 V supply) and independent output common-mode voltage control via dedicated CM pins. Its internal feedback network stabilizes operation down to 6 dB gain while maintaining >90 dB CMRR and <4 mV differential input offset.

It integrates a precision output common-mode servo loop with 700 MHz small-signal bandwidth and 110 V/μs slew rate, enabling DC-coupled interfacing to ADCs without external level-shifting. The device supports single-supply operation with rail-to-rail output swing (4.4–5.6 V differential) and fast turn-on/turn-off timing (55 ns / 10 μs).

Key Specifications

Pinout & Package

The THS4509RGTR is housed in a 3.00 mm × 3.00 mm, 16-pin VQFN package (RGT) with exposed thermal pad for enhanced thermal dissipation. Pin 1 is marked by a dot; pins 4 and 9 are dual CM inputs; pins 5–8 are tied VS+; pins 13–16 are tied VS−.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar fully-differential amplifier applications.

Compared with THS4509RGTR, THS4508RGTR offers identical footprint but narrower input common-mode range and higher distortion, while LMH5401RTVT provides ultra-wideband performance at the cost of increased power and loss of integrated common-mode control - making THS4509RGTR optimal for precision 5-V DC-coupled ADC driver applications.

Availability

THS4509RGTR is available at Aetrix Electronics and suitable for high-speed data acquisition, wireless infrastructure, test and measurement, and medical imaging applications requiring stable component supply, full industrial temperature support (–40°C to +85°C), and long-term production continuity.

Supply support for THS4509RGTR 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, embedded processing, and connectivity technologies, with over 90 years of innovation in precision signal chain solutions.

The THS4509RGTR belongs to TI's high-speed differential amplifier product line, engineered specifically for DC-coupled, low-distortion interfacing between precision sensors, DACs, and high-resolution ADCs in 3–5 V systems.

FAQ

What is the minimum stable gain for THS4509RGTR and why does it matter?

The THS4509RGTR has a minimum stable gain of 2 V/V (6 dB). This is critical because attempting to operate below this gain risks oscillation due to phase margin degradation. The internal compensation is optimized for gains ≥6 dB, ensuring stability without external components - simplifying design for fixed-gain IF amplifiers and anti-aliasing filters in data acquisition systems using THS4509RGTR.

How does THS4509RGTR achieve DC-coupled operation with ADCs?

THS4509RGTR achieves DC-coupled operation via its dedicated CM input pins (pins 4 and 9), which allow precise control of output common-mode voltage with ±3-mV typical offset from the set value. When configured to match the ADC's reference common-mode (e.g., 2.5 V for a 5-V ADC), THS4509RGTR eliminates the need for AC-coupling capacitors and level-shifting circuitry - preserving low-frequency response and reducing component count in systems like ultrasound receivers using THS4509RGTR.

What thermal considerations apply to THS4509RGTR in the RGT package?

The THS4509RGTR in the 16-pin VQFN (RGT) package features an exposed thermal pad that must be soldered to a PCB copper pour for effective heat dissipation. With R_θJA = 49.8°C/W and maximum power dissipation of 225 mW at +85°C ambient, proper thermal land design - including ≥4 thermal vias under the pad connected to inner ground planes - is essential to prevent junction temperature exceedance. Failure to implement this per TI SLMA002/SLMA004 guidelines risks permanent damage to THS4509RGTR.

Can THS4509RGTR operate from a 3-V supply, and how does performance change?

Yes, THS4509RGTR is specified for 3 V to 5.25 V operation. At 3 V supply, small-signal bandwidth drops to 1.6 GHz (vs. 1.9 GHz at 5 V), slew rate decreases to 3500 V/μs, and harmonic distortion degrades (HD3 = –54 dBc at 100 MHz vs. –80 dBc). Input common-mode range narrows to –0.4 V to +0.4 V. These trade-offs make THS4509RGTR viable for low-power portable instruments but favor 5-V operation for maximum linearity and bandwidth in THS4509RGTR-based designs.

What is the function of the PD pin on THS4509RGTR and how is it controlled?

The PD (power-down) pin (pin 12) places THS4509RGTR into low-power mode when driven logic-low (≤0.7 V + VS−), reducing quiescent current to 0.65 mA. It remains active when open or logic-high (>2.1 V + VS−). Turnon delay is 55 ns; turnoff delay is 10 μs. This enables dynamic power management in multi-channel DAQ systems - for example, cycling individual THS4509RGTR channels during idle periods to extend battery life in portable test gear.