BUF634AIDR [Texas Instruments]

The BUF634A device is a high-performance, high-fidelity, open-loop buffer that is capable of driving 250 mA of output current. The BUF634A is a 36-V device with an adjustable bandwidth of 35 MHz to 210 MHz, which is accomplished by varying the value of an external resistor between the V– and BW pins.

The BUF634A device can be used as a standalone open-loop driver, or used inside the feedback loop of a precision op amp to provide both high-precision and large output current drive with improved capacitive load drive.

For low-power applications, the BUF634A device operates on a 1.5-mA quiescent current with a 250-mA output, 3750-V/µs slew rate, and 35-MHz bandwidth. The device consumes 8.5-mA quiescent current in wide-bandwidth mode with a 210-MHz bandwidth. The BUF634A is fully protected by an internal current limit in its output stage and by thermal shutdown, making the device rugged and easy to use.

The BUF634A device is rated to function over the extended industrial temperature range of –40°C to +125°C. The BUF634A comes in three packages: D (SOIC), DRB (VSON), and DDA (HSOIC). The DRB (VSON) and DDA (HSOIC) packages have excellent thermal performance resulting from the thermal pad on the bottom side. The DRB package comes in a very small form factor of 3.0 mm × 3.0 mm, making the device a very suitable option for portable and size-constrained applications.

• Pin-Selected Bandwidth: 35 MHz to 210 MHz
• High Output Current: 250 mA
• Slew Rate: 3750 V/µs
• Low Quiescent Current: 1.5 mA (35-MHz BW)
• Wide Supply Range: ±2.25 V to ±18 V
• Internal Output Current Limit
• Thermal Shutdown Protection
• Available in Packages with Thermal Pad
• Extended Temperature Operation: –40°C to +125°C

Key Features

1. High 250mA output-current capability
BUF634AIDR can deliver high output current compared with a standard op amp output stage, making it useful for headphones, cables, capacitive loads, and other demanding loads.

2. Very high 3750V/µs slew rate
The high slew rate allows the buffer to follow fast-changing signals with low slew-induced distortion, which is useful in high-speed analog and audio signal paths.

3. Pin-selectable bandwidth from 35MHz to 210MHz
The device can operate in a lower-power 35MHz mode or a wide-bandwidth 210MHz mode, giving designers flexibility to balance bandwidth, power consumption, and stability.

4. Wide ±2.25V to ±18V supply range
The buffer supports a wide supply range, allowing use in low-voltage systems as well as ±12V or ±15V analog designs.

5. Low quiescent current in low-power mode
In low-power applications, BUF634A operates with about 1.5mA quiescent current while still providing 250mA output capability and 35MHz bandwidth.

6. Unity-gain open-loop buffer architecture
The device is a unity-gain, open-loop buffer intended for applications requiring large output current drive or large slew rates. It can also be used inside an op amp feedback loop to increase output current and improve capacitive-load drive capability.

7. Built-in protection functions
BUF634A includes internal output current limiting and thermal shutdown protection, improving robustness when driving difficult or heavy loads.

8. Standard SOIC-8 package
The SOIC-8 package is widely used, easy to assemble, and suitable for production SMT designs.