Texas Instruments LMH6704MAX/NOPB

Overview

LMH6704MAX/NOPB from Texas Instruments is a 650 MHz current-feedback selectable-gain buffer IC with user-configurable +1, +2, or −1 V/V gain, ±90 mA output drive, 3000 V/µs slew rate, and integrated 465 Ω feedback/gain resistors-designed for high-fidelity video distribution, ADC/DAC buffering, and RGB signal routing in HDTV and broadcast systems.

For engineers reviewing the LMH6704MAX/NOPB datasheet, LMH6704MAX/NOPB pinout, LMH6704MAX/NOPB application, or LMH6704MAX/NOPB equivalent, key selection criteria include small-signal bandwidth at AV = +1 (650 MHz), differential gain/phase accuracy (0.02%/0.02°), disable timing (10 ns enable/disable), output noise (9.3 nV/√Hz at AV = +1), and SOIC-8 thermal resistance (θJA = 160°C/W).

Technical Context

The LMH6704MAX/NOPB implements a current-feedback amplifier architecture with on-die RF = RG = 465 Ω, enabling stable gain configuration without external resistors. Its internal bias circuitry supports split-supply (±4 V to ±6 V) or single-supply operation with no internal ground reference.

Gain selection is achieved by configuring pins 3 (+IN) and 4 (−IN): AV = +2 requires −IN grounded and +IN driven; AV = +1 connects +IN to signal and leaves −IN open; AV = −1 grounds +IN and drives −IN. The disable pin (Pin 5) provides TTL-compatible control (VIH ≥ 2.0 V, VIL ≤ 0.8 V) to place output in high-Z state with 250 µA quiescent current.

Key Specifications

Pinout & Package

LMH6704MAX/NOPB is housed in an 8-pin SOIC package (Package Number D0008A), 3.91 mm wide, 4.9 mm long, 1.75 mm max height, RoHS-compliant matte tin lead finish, MSL Level-1.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar selectable-gain buffer applications.

Compared with LMH6704MAX/NOPB, LMH6703MAX/NOPB trades disable capability for 700 MHz more bandwidth, while THS3201DGNR offers greater flexibility and drive strength at the cost of board space and design complexity from external resistors.

Availability

LMH6704MAX/NOPB is available at Aetrix Electronics and suitable for HDTV signal distribution, ADC driver interface, and RGB graphics routing requiring stable component supply, long-term industrial lifecycle support, and traceable sourcing.

Supply support for LMH6704MAX/NOPB 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 high-performance signal chain solutions with over 50 years of innovation in amplifier design.

The LMH6704MAX/NOPB belongs to TI's LMH™ high-speed buffer family, engineered specifically for wide-dynamic-range video, instrumentation, and communications systems demanding ultra-low distortion and DC-coupled fidelity.

FAQ

What gain configurations does the LMH6704MAX/NOPB support, and how are they selected?

The LMH6704MAX/NOPB supports three fixed gain configurations: +1 V/V, +2 V/V, and −1 V/V. Selection is accomplished by connecting pins 3 (+IN) and 4 (−IN) as specified in Table 1 of the datasheet-no external resistors are needed. For AV = +2, −IN is grounded and +IN receives the signal; for AV = +1, +IN is driven and −IN is left open; for AV = −1, +IN is grounded and −IN is driven. All configurations leverage the internal 465 Ω RF/RG network for precision and temperature stability.

How does the disable function operate on the LMH6704MAX/NOPB, and what is its impact on power consumption?

The LMH6704MAX/NOPB disable pin (Pin 5) is TTL-compatible: applying ≤0.8 V disables the amplifier, placing output, input, and feedback nodes in high-impedance state with 250 µA total supply current (350 µA on VS+, 250 µA on VS−, plus 100 µA flowing out the DIS pin). At ≥2.0 V or floating, the device enables fully with 12.5 mA typical supply current. Disable timing is 10 ns for both enable and disable transitions, with <50 mVPP output glitch.

Can the LMH6704MAX/NOPB drive 75 Ω video loads directly, and what layout practices improve stability?

Yes-the LMH6704MAX/NOPB delivers ±90 mA and is explicitly characterized for 75 Ω loads in video applications. To ensure stability with capacitive loads (e.g., coaxial cables), TI recommends adding a series output resistor (RISO): 22 Ω for 47 pF, 39 Ω for 15 pF, or 56 Ω for 4.7 pF, as shown in Figure 5. Layout best practices include removing ground/power planes near pins 1–4, using 0.01 µF + 0.1 µF bypass capacitors placed <2 mm from each supply pin, and back-terminating 75 Ω lines at the load.

What is the small-signal bandwidth of the LMH6704MAX/NOPB at different output amplitudes and gains?

At AV = +1, the LMH6704MAX/NOPB achieves 650 MHz (−3 dB) with 0.5 VPP output. At AV = +2, bandwidth is 450 MHz (0.5 VPP) and 400 MHz (2 VPP). Full-power gain flatness extends to 200 MHz, verified under 2 VPP conditions. These values are measured with RL = 100 Ω and ±5 V supplies; bandwidth scales predictably with supply voltage and load, as confirmed in Figures 1–4 of the datasheet.

Does the LMH6704MAX/NOPB require external compensation, and how is unity-gain stability ensured?

No external compensation is required for standard gain configurations. However, for AV = +1, the integrated 465 Ω feedback resistor causes slight peaking; TI recommends the "Alternate Unity Gain Configuration" (Figure 20) using a 75 Ω resistor between +IN and ground to raise noise gain and eliminate peaking-verified in Figure 21. This method maintains 650 MHz bandwidth while increasing output-referred voltage noise by only 10% (from 9.3 to 10.5 nV/√Hz).