250-mA high-speed buffer - see BUF634A for upgraded version

BUF634 is not recommended for new designs
Although this product continues to be in production to support previous designs, we don't recommend it for new designs. Consider one of these alternates:
open-in-new Compare alternates
Drop-in replacement with upgraded functionality to the compared device
BUF634A ACTIVE 210-MHz, 250-mA high-speed buffer BUF634A has higher slew rate (3750 V/µs) and wider bandwidth (210 MHz) at a 40% lower quiescent current (8.5 mA) and is available at a lower cost

Product details

Architecture Fixed Gain/Buffer Number of channels 1 Total supply voltage (+5 V = 5, ±5 V = 10) (min) (V) 5 Total supply voltage (+5 V = 5, ±5 V = 10) (max) (V) 36 GBW (typ) (MHz) 180 BW at Acl (MHz) 180 Acl, min spec gain (V/V) 1 Slew rate (typ) (V/µs) 2000 Vn at flatband (typ) (nV√Hz) 4 Vn at 1 kHz (typ) (nV√Hz) 4 Iq per channel (typ) (mA) 15 Vos (offset voltage at 25°C) (max) (mV) 100 Rail-to-rail No Features Adjustable BW/IQ/IOUT Rating Catalog Operating temperature range (°C) -40 to 125 Input bias current (max) (pA) 20000000 Offset drift (typ) (µV/°C) 100 Iout (typ) (mA) 250 2nd harmonic (dBc) 75 3rd harmonic (dBc) 83 Frequency of harmonic distortion measurement (MHz) 1
Architecture Fixed Gain/Buffer Number of channels 1 Total supply voltage (+5 V = 5, ±5 V = 10) (min) (V) 5 Total supply voltage (+5 V = 5, ±5 V = 10) (max) (V) 36 GBW (typ) (MHz) 180 BW at Acl (MHz) 180 Acl, min spec gain (V/V) 1 Slew rate (typ) (V/µs) 2000 Vn at flatband (typ) (nV√Hz) 4 Vn at 1 kHz (typ) (nV√Hz) 4 Iq per channel (typ) (mA) 15 Vos (offset voltage at 25°C) (max) (mV) 100 Rail-to-rail No Features Adjustable BW/IQ/IOUT Rating Catalog Operating temperature range (°C) -40 to 125 Input bias current (max) (pA) 20000000 Offset drift (typ) (µV/°C) 100 Iout (typ) (mA) 250 2nd harmonic (dBc) 75 3rd harmonic (dBc) 83 Frequency of harmonic distortion measurement (MHz) 1
SOIC (D) 8 29.4 mm² 4.9 x 6 TO-220 (KC) 5 45.212 mm² 10.16 x 4.45 TO-263 (KTT) 5 154.8384 mm² 10.16 x 15.24
  • A newer version of this device is now available: BUF634A
  • High output current: 250 mA
  • Slew rate: 2000 V/µs
  • Pin-selected bandwidth: 30 MHz to 180 MHz
  • Low quiescent current: 1.5 mA (30 MHz BW)
  • Wide supply range: ±2.25 to ±18 V
  • Internal current limit
  • Thermal shutdown protection
  • 8-pin PDIP, SOIC-8, 5-lead TO-220, 5-lead DDPAK-TO-263 surface-mount
  • A newer version of this device is now available: BUF634A
  • High output current: 250 mA
  • Slew rate: 2000 V/µs
  • Pin-selected bandwidth: 30 MHz to 180 MHz
  • Low quiescent current: 1.5 mA (30 MHz BW)
  • Wide supply range: ±2.25 to ±18 V
  • Internal current limit
  • Thermal shutdown protection
  • 8-pin PDIP, SOIC-8, 5-lead TO-220, 5-lead DDPAK-TO-263 surface-mount

The BUF634 is a high speed, unity-gain open-loop buffer recommended for a wide range of applications. The BUF634 can be used inside the feedback loop of op amps to increase output current, eliminate thermal feedback, and improve capacitive load drive.

For low power applications, the BUF634 operates on 1.5-mA quiescent current with 250-mA output,
2000-V/µs slew rate, and 30-MHz bandwidth. Bandwidth can be adjusted from 30 MHz to 180 MHz by connecting a resistor between V– and the BW Pin.

Output circuitry is fully protected by internal current limit and thermal shut-down, making the device rugged and easy to use.

The BUF634 is available in a variety of packages to suit mechanical and power dissipation requirements. Types include 8-pin PDIP, SOIC-8 surface-mount, 5-lead TO-220, and a 5-lead DDPAK-TO-263 surface-mount plastic power package.

The upgraded device, BUF634A offers a wider bandwidth (210 MHz) and a higher slew rate (3750 V/µs) at 40% lower quiescent current. See the Device Comparison Table for a selection of unity-gain, open-loop buffers from Texas Instruments.

The BUF634 is a high speed, unity-gain open-loop buffer recommended for a wide range of applications. The BUF634 can be used inside the feedback loop of op amps to increase output current, eliminate thermal feedback, and improve capacitive load drive.

For low power applications, the BUF634 operates on 1.5-mA quiescent current with 250-mA output,
2000-V/µs slew rate, and 30-MHz bandwidth. Bandwidth can be adjusted from 30 MHz to 180 MHz by connecting a resistor between V– and the BW Pin.

Output circuitry is fully protected by internal current limit and thermal shut-down, making the device rugged and easy to use.

The BUF634 is available in a variety of packages to suit mechanical and power dissipation requirements. Types include 8-pin PDIP, SOIC-8 surface-mount, 5-lead TO-220, and a 5-lead DDPAK-TO-263 surface-mount plastic power package.

The upgraded device, BUF634A offers a wider bandwidth (210 MHz) and a higher slew rate (3750 V/µs) at 40% lower quiescent current. See the Device Comparison Table for a selection of unity-gain, open-loop buffers from Texas Instruments.

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Technical documentation

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Type Title Date
* Data sheet BUF634 250-mA High-Speed Buffer datasheet (Rev. B) PDF | HTML 29 Mar 2019
Application note BUF634A and BUF634 Thermal Performance Comparison PDF | HTML 18 Oct 2021
Application note Optimizing LCR Meter Front-End Design for Accurate Impedance Measurements PDF | HTML 20 Jan 2021
EVM User's guide BUF634AD Evaluation module 18 Feb 2019
E-book The Signal e-book: A compendium of blog posts on op amp design topics 28 Mar 2017
Application note Combining an Amplifier with the BUF634 02 Oct 2000
Application note Add Current Limit to the BUF634 27 Sep 2000
Application note Power Amplifier Stress and Power Handling Limitations 27 Sep 2000

Design & development

For additional terms or required resources, click any title below to view the detail page where available.

Evaluation board

BUF634ADRBEVM — 250-mA high-speed buffer evaluation module

The BUF634ADRBEVM is an evaluation module (EVM) for the BUF634A high-speed buffer in the DRB (8-pin DFN) package. The BUF634ADRBEVM features two BUF634AIDRB devices and is designed to quickly demonstrate the functionality and versatility of the buffer. Optionally, the buffers can be configured as (...)
User guide: PDF | HTML
Not available on TI.com
Simulation model

BUF634 PSpice Model (Rev. B)

SBOM003B.ZIP (62 KB) - PSpice Model
Simulation model

BUF634 TINA-TI Reference Design (Rev. C)

SBOC135C.TSC (405 KB) - TINA-TI Reference Design
Simulation model

BUF634 TINA-TI Spice Model (Rev. B)

SBOM204B.ZIP (10 KB) - TINA-TI Spice Model
Calculation tool

ANALOG-ENGINEER-CALC — Analog engineer's calculator

The analog engineer’s calculator is designed to speed up many of the repetitive calculations that analog circuit design engineers use on a regular basis. This PC-based tool provides a graphical interface with a list of various common calculations ranging from setting operational-amplifier (...)
Calculation tool

VOLT-DIVIDER-CALC — Voltage Divider Determines A Set of Resistors for a Voltage Divider

VOLT-DIVIDER-CALC quickly determines a set of resistors for a voltage divider. This KnowledgeBase Javascript utility can be used to find a set of resistors for a voltage divider to achieve the desired output voltage. This calculator can also be used to design non-inverting attentuation circuits.

(...)

Simulation tool

PSPICE-FOR-TI — PSpice® for TI design and simulation tool

PSpice® for TI is a design and simulation environment that helps evaluate functionality of analog circuits. This full-featured, design and simulation suite uses an analog analysis engine from Cadence®. Available at no cost, PSpice for TI includes one of the largest model libraries in the (...)
Simulation tool

TINA-TI — SPICE-based analog simulation program

TINA-TI provides all the conventional DC, transient and frequency domain analysis of SPICE and much more. TINA has extensive post-processing capability that allows you to format results the way you want them. Virtual instruments allow you to select input waveforms and probe circuit nodes voltages (...)
User guide: PDF
Package Pins Download
SOIC (D) 8 View options
TO-220 (KC) 5 View options
TO-263 (KTT) 5 View options

Ordering & quality

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