Texas Instruments BUF634P

Overview

BUF634P from Texas Instruments is a high-speed, unity-gain, open-loop buffer IC designed for current-boosting and capacitive load driving in precision analog signal paths. It delivers 250mA continuous output current, 2000V/µs slew rate, and pin-selectable bandwidth from 30MHz to 180MHz across ±2.25V to ±18V supplies - enabling use as an op amp current booster in test equipment and ATE pin drivers.

For engineers reviewing the BUF634P datasheet, BUF634P pinout, BUF634P application, or BUF634P equivalent, key selection criteria include its adjustable bandwidth via external resistor, thermal shutdown protection, internal current limiting, low-quiescent-current mode (1.5mA), and compatibility with SOIC-8, TO-220-5, and TO-263-5 packages.

Technical Context

The BUF634P implements an open-loop complementary follower architecture with externally configurable quiescent current and bandwidth via the BW pin. Its dual operating modes-low-IQ (1.5mA, 30MHz) and wide-BW (15mA, 180MHz)-are selected by connecting a resistor between V– and BW, directly setting bias current without altering gain or topology.

It operates as a unity-gain voltage buffer with no internal feedback network, relying on external system-level compensation. Input impedance exceeds 1400MΩ || 5pF in low-IQ mode, while output drive capability maintains ±250mA into 67Ω loads with <0.9V headroom at ±15V supplies and includes robust short-circuit and thermal shutdown protection.

Key Specifications

Pinout & Package

BUF634P is available in 8-pin SOIC (D package), 5-pin TO-220 (KC package), and 5-pin TO-263 (KTT package). Pin functions are identical across packages: VIN (input), VO (output), V+ and V– (power rails), and BW (bandwidth adjust). NC pins are unconnected.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BUF634A and LMH6321, the BUF634P offers the lowest quiescent current in low-power mode (1.5mA), widest supply range (±2.25V to ±18V), and proven ruggedness in industrial valve and solenoid driver roles - making it optimal for cost-sensitive, thermally constrained, or wide-rail applications where 180MHz bandwidth suffices.

Availability

BUF634P is available at Aetrix Electronics and suitable for valve driver, solenoid driver, and op amp current booster applications requiring stable component supply, long-term industrial lifecycle support, and traceable sourcing from authorized channels.

Supply support for BUF634P 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 company specializing in analog and embedded processing technologies, with leadership in high-performance amplifiers and precision signal chain solutions.

The BUF634P belongs to TI's high-speed buffer product line, engineered for applications demanding high output current, wide bandwidth, and robust protection - particularly in industrial automation, test equipment, and video signal distribution.

FAQ

What is the maximum continuous output current of the BUF634P?

The BUF634P delivers ±250mA continuous output current across all supported packages and operating conditions. This rating holds for both sourcing and sinking, with output voltage swing degrading predictably under load - e.g., maintaining ≥±12.9V at ±150mA with ±15V supplies. Short-circuit current reaches ±350mA to ±550mA depending on mode and temperature.

How does the BW pin function on the BUF634P?

The BW pin on the BUF634P sets quiescent current and bandwidth by connecting an external resistor between BW and V–. A high resistance (open circuit) selects low-IQ mode (1.5mA, 30MHz); decreasing resistance increases IQ and bandwidth up to 180MHz at ~15mA. Figure 6-9 in the datasheet provides the exact R–IQ–BW relationship, and no external capacitor or bias network is required.

Does the BUF634P require external compensation or feedback components?

No, the BUF634P is an open-loop unity-gain buffer and requires no external feedback or compensation components. It is internally compensated for stability under all specified loads, including 1nF capacitive loads. However, when used inside an op amp's feedback loop (e.g., as a current booster), the host op amp's compensation remains unchanged - the BUF634P adds no phase shift that affects overall loop stability.

What thermal protection features does the BUF634P include?

The BUF634P integrates thermal shutdown that activates at ~175°C junction temperature, disabling output until junction cools by ~10°C. This protection is fully internal, requires no external circuitry, and recovers automatically. Thermal performance varies by package: TO-220 offers 32.1°C/W RθJA, TO-263 offers 41.8°C/W, and SOIC-8 offers 123°C/W - so heatsinking is essential in high-power wide-BW mode.

Can the BUF634P operate from a single supply?

Yes, the BUF634P supports single-supply operation by referencing V– to ground and applying positive voltage to V+. For example, with V– = 0V and V+ = +36V, it operates across 0V to +36V - but input and output voltage ranges scale accordingly (e.g., linear input range becomes 0V to +34V). The device retains full functionality, including BW pin adjustment and thermal protection, in single-supply configurations.