Texas Instruments BUF634FKTTTE3

Overview

BUF634FKTTTE3 from Texas Instruments is a unity-gain, open-loop high-speed 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, 30–180MHz pin-selectable bandwidth, ±2.25V to ±18V dual supply operation, and internal thermal shutdown-enabling robust valve, solenoid, and video driver implementations.

For engineers reviewing the BUF634FKTTTE3 datasheet, BUF634FKTTTE3 pinout, BUF634FKTTTE3 application, or BUF634FKTTTE3 equivalent, this page provides verified package mapping (TO-263-5), terminal functions, real-world application cards, and two validated alternative parts with documented functional trade-offs for op amp current boosting, line driving, and test equipment design.

Technical Context

The BUF634FKTTTE3 implements an open-loop complementary follower architecture with externally adjustable bandwidth via a resistor between V– and BW pins. Its output stage operates in Class AB with internal current limiting and thermal shutdown circuitry, enabling safe operation into shorted or highly capacitive loads without external protection components.

It supports two distinct operating modes: low-quiescent-current mode (1.5mA, 30MHz) and wide-bandwidth mode (15mA, 180MHz), both maintaining 250mA output drive capability and unity gain accuracy within ±5% across 1kΩ–67Ω loads. Input impedance exceeds 1.4GΩ in low-IQ mode, while output impedance remains below 7Ω at DC and 100kHz.

Key Specifications

Pinout & Package

BUF634FKTTTE3 uses the KTT (TO-263-5) surface-mount plastic power package with exposed thermal pad, measuring 10.16mm × 15.24mm, optimized for high-power dissipation in compact layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BUF634A and LMH6321, BUF634FKTTTE3 delivers optimal thermal robustness in TO-263 packaging, field-proven reliability in industrial valve/solenoid drivers, and seamless drop-in compatibility with legacy BUF634 designs-making it the preferred choice for high-current, thermally demanding analog output stages.

Availability

BUF634FKTTTE3 is available at Aetrix Electronics and suitable for valve driver, solenoid driver, and ATE pin driver applications requiring stable component supply, long-term industrial lifecycle support, and traceable sourcing from Texas Instruments' authorized channel.

Supply support for BUF634FKTTTE3 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 connectivity technologies with decades of high-reliability industrial IC design expertise.

The BUF634 product line was engineered specifically for high-current, high-speed analog buffering-targeting applications where op amps lack output drive, thermal stability, or capacitive load resilience.

FAQ

What is the maximum continuous output current of the BUF634FKTTTE3?

The BUF634FKTTTE3 delivers ±250mA continuous output current into resistive loads at TA = 25°C and VS = ±15V. This rating holds across its full operating temperature range (–40°C to +125°C) and is enforced by internal current limiting that activates at ±350mA to ±550mA depending on junction temperature and operating mode. The TO-263-5 package's low RθJC(bot) of 2.4°C/W enables sustained 250mA operation with appropriate PCB copper area.

How do I configure the bandwidth of the BUF634FKTTTE3?

Bandwidth is configured by connecting a resistor between the V– pin and BW pin: open circuit yields 30MHz (low-IQ mode), while 0Ω connection yields 180MHz (wide-BW mode). Resistor values between ∞ and 0Ω scale bandwidth linearly per Figure 6-9 in the datasheet. For example, a 10kΩ resistor sets ~100MHz bandwidth. No external capacitors or feedback networks are required-bandwidth adjustment is purely resistive and mode-independent.

Does the BUF634FKTTTE3 require external compensation for stability?

No, the BUF634FKTTTE3 is unity-gain stable without external compensation. It maintains phase margin >45° into 1nF capacitive loads in both low-IQ and wide-BW modes, as confirmed by Figures 6-5 through 6-6 and 6-23 through 6-24. This eliminates the need for series isolation resistors or RC snubbers typically required with op amps driving cables or piezoelectric actuators-simplifying layout and improving transient response.

What thermal protection features does the BUF634FKTTTE3 include?

The BUF634FKTTTE3 integrates thermal shutdown that activates at 175°C junction temperature, halting output conduction until junction temperature falls by ~10°C. Recovery is automatic and does not require power cycle. This protection works independently of supply voltage or load condition and is validated across all packages. The TO-263-5 package's RθJA of 41.8°C/W (with 2-in² 2-oz copper) ensures safe operation up to 1.8W dissipation at 85°C ambient-critical for solenoid and motor gate driving.

Can the BUF634FKTTTE3 be used to boost the output current of any op amp?

Yes-the BUF634FKTTTE3 is explicitly designed to be placed inside the feedback loop of op amps to increase output current, eliminate thermal feedback, and improve capacitive load drive. It accepts standard op amp outputs at VIN and delivers 250mA at VO while maintaining unity gain (0.95–0.99V/V). Its high input impedance (>1.4GΩ in low-IQ mode) minimizes loading on the driving op amp, and its low output impedance (<7Ω) ensures accurate current delivery without gain error amplification.