Texas Instruments THS4508RGTR

Overview

THS4508RGTR from Texas Instruments is a wideband, low-noise, fully differential amplifier optimized for 5-V single-supply data acquisition systems. It delivers 2 GHz small-signal bandwidth, –72 dBc HD2 and –79 dBc HD3 at 100 MHz (2 V_PP, G = 10 dB), 6400 V/µs slew rate, and 2 ns 1% settling time-enabling high-fidelity signal conditioning ahead of high-speed ADCs like the ADS5500.

For engineers reviewing the THS4508RGTR datasheet, THS4508RGTR pinout, THS4508RGTR application, or THS4508RGTR equivalent, key selection criteria include its output common-mode control accuracy (±5 mV offset), power-down capability (0.65 mA quiescent), QFN-16 thermal performance, and verified SFDR of 82 dBc when driving 125 MSPS ADCs at 70 MHz.

Technical Context

The THS4508RGTR employs a fully differential architecture with independent input and output common-mode control paths. Its input stage supports rail-to-rail common-mode range down to the negative rail (–0.3 V), while the output common-mode circuit maintains setpoint accuracy within ±5 mV across 1.25–3.75 V CM input range and provides 700 MHz small-signal bandwidth for CM feedback.

It operates with minimum gain of 2 V/V (6 dB) but is characterized and optimized for 10-dB gain configurations, achieving 1.5 GHz large-signal bandwidth and 400 MHz 0.1-dB flatness under 2 V_PP conditions-critical for pulsed RF and high-resolution imaging front-ends.

Key Specifications

Pinout & Package

The THS4508RGTR is housed in a thermally enhanced 16-pin QFN package (RGT) with exposed thermal pad requiring connection to PCB ground plane for reliable 125°C junction operation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with THS4508RGTR, THS4521RGTT trades 0.5 GHz bandwidth and power-down capability for 17 mA lower quiescent current, while LMH5401RTVT extends bandwidth by 2.5 GHz but increases power consumption by 11 mA and removes on-chip CM control-requiring additional external components for dc-coupled ADC interfacing.

Availability

THS4508RGTR is available at Aetrix Electronics and suitable for high-speed data acquisition, wireless infrastructure, medical ultrasound imaging, and test & measurement equipment requiring stable component supply and guaranteed long-term industrial temperature support (–40°C to +85°C).

Supply support for THS4508RGTR 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 over 50 years of innovation in precision amplifiers and data converter interfaces.

The THS4508RGTR belongs to TI's high-speed differential amplifier product line, designed specifically for dc-coupled, single-supply 5-V data acquisition systems demanding ultra-low distortion, wide bandwidth, and robust thermal performance in compact QFN packages.

FAQ

What is the maximum operating supply voltage for the THS4508RGTR?

The THS4508RGTR has an absolute maximum supply voltage rating of 5.5 V (VS+ to VS–), with specified operation from 3.75 V to 5.25 V. At 5 V nominal supply, it draws 39.2 mA quiescent current and achieves full AC performance including 2 GHz bandwidth and –79 dBc HD3. Operation outside the 3.75–5.25 V range may degrade distortion or stability and is not characterized.

Does the THS4508RGTR support dc-coupled ADC interfaces?

Yes, the THS4508RGTR supports dc-coupled ADC interfaces via its integrated output common-mode control circuit. When the CM pin is left open, the internal default sets output common-mode to 2.5 V (mid-supply); applying an external voltage (1.25–3.75 V) allows precise adjustment with ≤5-mV offset error. This eliminates need for ac-coupling capacitors when interfacing to mid-supply-referenced ADCs such as the ADS5500.

What is the purpose of the PD (power-down) pin on the THS4508RGTR?

Pin 12 (PD) on the THS4508RGTR controls power-down mode: logic low (≤0.7 V) reduces quiescent current to 0.65 mA, while logic high (≥2.1 V) or open circuit enables normal operation at 39.2 mA. Turn-on delay is 55 ns; turn-off delay is 10 µs. This feature enables dynamic power gating in battery-powered or duty-cycled systems without requiring supply rail sequencing.

Can the THS4508RGTR be used with gains below 2 V/V?

No, the THS4508RGTR is not stable at gains below 2 V/V (6 dB). Its minimum stable gain is 2 V/V, as confirmed by stability analysis and layout recommendations in the datasheet. Attempting unity-gain or inverting configurations risks oscillation or degraded phase margin. For lower-gain applications, consider alternatives such as the THS4521RGTT (minimum gain = 1 V/V) or redesign with external attenuation.

How should the thermal pad on the THS4508RGTR QFN package be handled?

The exposed thermal pad on the THS4508RGTR's RGT package must be soldered to a solid copper ground plane using a standard thermal via pattern (≥4 vias, 0.3-mm diameter, spaced ≤1 mm apart). Failure to connect the pad results in θ_JA degrading from 39.5°C/W to >60°C/W, risking junction temperature exceedance above 125°C during continuous 39.2-mA operation at +85°C ambient - potentially causing reliability failure or parametric shift.