Texas Instruments LMH3401IRMST

Overview

LMH3401IRMST from Texas Instruments is a 7-GHz ultra-wideband, fixed-gain (16 dB), fully-differential amplifier optimized for single-ended-to-differential conversion in RF/IF and high-speed data acquisition systems. It delivers –96 dBc HD2 / –102 dBc HD3 at 10 MHz, 45 dBm OIP3 at 200 MHz, and operates from ±1.65 V to ±2.5 V supplies with 55 mA quiescent current. It drives GSPS ADCs such as the ADC12J4000 in broadband communications and test equipment.

For engineers reviewing the LMH3401IRMST datasheet, LMH3401IRMST pinout, LMH3401IRMST application, or LMH3401IRMST equivalent, key selection criteria include its 7-GHz –3-dB bandwidth, differential output impedance of 20 Ω, CM control bandwidth of 3.3 GHz, power-down functionality with 10 ns turn-on delay, and UQFN-14 package compatibility with high-density RF layouts.

Technical Context

The LMH3401IRMST employs a complementary BiCMOS architecture enabling simultaneous wide bandwidth and low distortion. Its internal resistor network eliminates external gain-setting components and ensures stable 16 dB voltage gain across DC–2 GHz with <0.1-dB flatness up to 700 MHz.

It features a dedicated CM pin (Pin 2) that directly controls output common-mode voltage with 0.98–1.01 V/V gain and ±27 mV offset, enabling precise alignment with ADC input requirements. The device supports both split-supply (±1.65 V to ±2.5 V) and single-supply operation, with independent PD (Pin 9) control for sub-6 mA power-down current.

Key Specifications

Pinout & Package

LMH3401IRMST is housed in a 2.50 mm × 2.50 mm, 14-lead UQFN package with wettable flanks, optimized for RF signal integrity and thermal dissipation (R_θJA = 101 °C/W). The exposed thermal pad must be soldered to PCB ground for optimal performance.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LMH5401RTAJ and LMH6554MA/NOPB, the LMH3401IRMST uniquely combines 7-GHz bandwidth with –96 dBc HD2 at 10 MHz and UQFN-14 packaging-making it the only option for compact, wideband ADC driver designs requiring DC–2 GHz linearity and sub-10 ns power management.

Availability

LMH3401IRMST is available at Aetrix Electronics and suitable for test & measurement equipment, broadband wireless infrastructure, and high-speed data acquisition systems requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for LMH3401IRMST 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 signal chain solutions.

The LMH3401IRMST belongs to TI's ultra-wideband amplifier product line, engineered specifically for demanding RF/IF and GSPS data converter interface applications where bandwidth, linearity, and power efficiency are co-critical.

FAQ

What is the maximum operating frequency of the LMH3401IRMST before gain drops by 3 dB?

The LMH3401IRMST has a guaranteed –3-dB small-signal bandwidth of 7 GHz when tested at VO = 200 mVPP under split-supply conditions (VS+ = 2.5 V, VS– = –2.5 V). This bandwidth is maintained across temperature (–40°C to 85°C) and supply voltage (3.3 V to 5.0 V), making LMH3401IRMST suitable for L-band and S-band RF sampling applications without external compensation.

How does the CM pin (Pin 2) function in the LMH3401IRMST?

The CM pin on the LMH3401IRMST directly controls the output common-mode voltage (V_{OUT_CM} = (OUT+ + OUT–)/2) with near-unity gain (0.98–1.01 V/V) and 3.3 GHz bandwidth. When set to 0 V, V_{OUT_CM} settles to –27 mV; it tracks V_CM within ±1.55 V of each rail. This allows precise alignment with ADC input common-mode requirements-essential for maximizing SNR in LMH3401IRMST-driven data converters.

Can the LMH3401IRMST drive a 100-Ω differential load effectively?

Yes-the LMH3401IRMST maintains –64 dBc HD2 and –72 dBc HD3 at 1 GHz into a 100-Ω differential load (RL = 100 Ω), as verified in Figure 14 of the SBOS695A datasheet. Its 20 Ω nominal output impedance provides good match to 100 Ω with <0.2 dB insertion loss, though optimal harmonic suppression is achieved at 200 Ω. For 100 Ω loads, LMH3401IRMST retains full 7-GHz bandwidth and 16 dB gain.

What is the power-down behavior of the LMH3401IRMST?

When the PD pin (Pin 9) is driven above 1.2 V, the LMH3401IRMST enters low-power sleep mode with quiescent current reduced to ≤6 mA. Turn-off and turn-on delays are both ≤10 ns, ensuring minimal disruption in time-division duplex (TDD) systems. In sleep mode, output is high-impedance, preserving signal chain integrity-critical for shared-bus architectures using LMH3401IRMST in multi-channel receivers.

Is the LMH3401IRMST compatible with single-supply operation?

Yes-the LMH3401IRMST supports true single-supply operation from 3.3 V to 5.0 V. With VS+ = 3.3 V and VS– = 0 V, it delivers 6.5 GHz bandwidth, –97 dBc HD2 at 10 MHz, and 16 dB gain. Input common-mode range extends from –0.3 V to 1.8 V, and output swings from 0.95 V to 2.25 V (single-ended), enabling direct interfacing with 3.3-V ADCs without level-shifting circuitry-simplifying design when using LMH3401IRMST in portable instrumentation.