Texas Instruments LMH6503MA

Overview

LMH6503MA from Texas Instruments is a wideband, DC-coupled, differential-input voltage-controlled gain amplifier with 135MHz −3dB bandwidth, 100MHz gain control bandwidth, and 70dB typical gain adjustment range over 10MHz. It integrates a linear V/V gain control interface (−1V to +1V), high-speed current-feedback output stage (1800 V/µs slew rate), and ±75mA linear output drive capability-designed for precision analog signal conditioning in RF receiver AGC loops and video line drivers.

For engineers reviewing the LMH6503MA datasheet, LMH6503MA pinout, LMH6503MA application, or LMH6503MA equivalent, this device requires attention to its dual-supply operation (±2.5V to ±6V), differential input common-mode range (±2.2V), VG input impedance (70kΩ), and external RG/RF resistor dependencies for gain calibration and bandwidth setting.

Technical Context

The LMH6503MA implements a two-stage architecture: an input transconductance stage converts differential voltage to current (IRG = VIN_DIFF / RG), followed by a voltage-controlled two-quadrant multiplier (K ≈ 1.72) and current-feedback op-amp output stage (transimpedance gain = RF). Gain is precisely expressed as AV = (RF / RG) × K × (VG + 1)/2, where VG ∈ [−1V, +1V] defines linear V/V scaling.

Its differential input supports >67dB CMRR up to 1MHz and enables noise-rejecting signal acquisition in long-line applications; the current-feedback output delivers stable large-signal response into 100Ω loads with <10% overshoot and 2.2ns rise time, while maintaining −57dBc THD at 20MHz with 2VPP output.

Key Specifications

Pinout & Package

LMH6503MA is housed in a 14-pin SOIC package (Package Code: D0014A) with standard JEDEC MS-012AC footprint (5.3mm × 10.2mm, 1.27mm pitch). Thermal resistance θJA = 138°C/W enables operation up to +85°C ambient with minimal heatsinking.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar variable-gain amplifier applications.

Compared with LMH6502MA and AD8367ARUZ, the LMH6503MA uniquely combines linear V/V gain control, differential DC-coupled inputs, and current-feedback output drive-making it the only option among the three suitable for precision video, instrumentation, and multi-channel coherent signal paths requiring matched gain and phase response.

Availability

LMH6503MA is available at Aetrix Electronics and suitable for RF receiver AGC, broadcast video line driving, high-speed DAC buffering, and voltage-controlled filter applications requiring stable component supply, full traceability, and long-term industrial lifecycle support.

Supply support for LMH6503MA 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-speed amplifiers and signal chain solutions.

The LMH6503MA belongs to TI's LMH™ high-speed amplifier family, engineered specifically for wideband, precision analog signal conditioning in communications infrastructure, test & measurement, and professional video systems.

FAQ

What is the maximum recommended supply voltage for LMH6503MA?

The absolute maximum supply voltage for LMH6503MA is ±6.3V (12.6V total), but the recommended operating range is ±2.5V to ±6V. At ±6V, supply current increases to 53mA and thermal dissipation must be managed via PCB copper area or heatsinking; TI specifies θJA = 138°C/W for SOIC. Operation at ±2.5V reduces power to 23mA while maintaining 100MHz gain control bandwidth and 70dB range, making it ideal for portable instrumentation.

How does LMH6503MA achieve linear V/V gain control across its full range?

The LMH6503MA achieves linear V/V gain control via an internal two-quadrant voltage-controlled multiplier with nominal gain factor K = 1.72. Its gain equation AV = (RF / RG) × K × (VG + 1)/2 explicitly defines linear dependence on VG over −1V to +1V. This architecture avoids log-antilog compression, delivering <±0.7dB gain matching between units and <±0.4dB accuracy over temperature-critical for multi-channel beamforming and calibrated test equipment where gain error directly impacts measurement uncertainty.

Can LMH6503MA be used with single-supply operation?

Yes, LMH6503MA supports single-supply operation by biasing the V− pin to ground and referencing VG to a "virtual ground" (e.g., V+/2 via resistor divider or op-amp buffer). The datasheet confirms VG range remains −1V to +1V relative to pin 11 (GND), and input common-mode range extends to ±2.2V. However, output swing is reduced to ±3.2V into 100Ω (vs. ±4.05V with dual supply), and PSRR degrades slightly-TI recommends using bypass capacitors and low-noise LDOs to maintain SNR in +5V-only systems.

What external components are required to set gain and bandwidth for LMH6503MA?

LMH6503MA requires two external resistors: RG (gain-setting) and RF (transimpedance feedback). RG determines input transconductance (IRG = VIN_DIFF / RG); TI recommends RG ≤ 1kΩ to limit input noise contribution. RF sets output gain (AV ∝ RF) and affects bandwidth-higher RF reduces bandwidth (e.g., RF = 2.4kΩ yields ~50MHz BW at AVMAX = 100). Both resistors must be 1% metal-film types placed close to pins 4/5 (RG) and pin 9 (RF) to preserve 135MHz small-signal response and minimize parasitic inductance.

How is output offset voltage managed in LMH6503MA designs?

LMH6503MA output offset is managed in two stages: first, apply −1.1V to VG to isolate the output stage and null its offset using an external trim pot (e.g., R14 on TI's LMH730033 eval board); second, apply +1.1V to VG and null residual input/multiplier offset with a second trim (e.g., R10). This two-point calibration reduces output offset to <80mV over temperature, though residual drift (~0.5mV/°C) remains due to VG-dependent offset terms-TI specifies ±350mV max over full VG range at 25°C.