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Texas Instruments BUF634UG4
- Part No.:
- BUF634UG4
- Manufacturer:
- Texas Instruments
- Category:
- Instrumentation, Op Amps, Buffer Amps
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
BUF634UG4.pdf
- Description:
- IC BUFFER 1 CIRCUIT 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:1,318
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Product details
Overview
BUF634UG4 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 (30–180MHz), operating across ±2.25V to ±18V supplies with internal current limiting and thermal shutdown. It is commonly used to augment op amp output stages in valve drivers, video drivers, and ATE pin drivers.
For engineers reviewing the BUF634UG4 datasheet, BUF634UG4 pinout, BUF634UG4 application, or BUF634UG4 equivalent, key selection criteria include its adjustable bandwidth via external resistor, low-quiescent-current mode (1.5mA), rugged protection features, and compatibility with SOIC-8, TO-220-5, and TO-263-5 packages - critical for thermal management in high-current line driver and motor driver designs.
Technical Context
The BUF634UG4 implements an open-loop complementary follower architecture with separate input and output stages decoupled to eliminate thermal feedback between gain and output devices. Its bandwidth is dynamically set by a resistor between V– and the BW pin, enabling precise trade-offs between speed (up to 180MHz) and quiescent current (as low as 1.5mA).
It features dual operating modes: wide-bandwidth mode (15mA IQ, 180MHz BW) and low-quiescent-current mode (1.5mA IQ, 30MHz BW), both supporting ±250mA output with rail-to-rail headroom of ≤2.5V at 150mA. Protection includes foldback current limiting and thermal shutdown triggered at 175°C junction temperature.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output current | ±250mA continuous - drives heavy capacitive or resistive loads without external transistors |
| Slew rate | 2000V/µs - enables fast settling for video, test, and pulse applications |
| Bandwidth range | 30MHz to 180MHz - selectable via external resistor on BW pin for design flexibility |
| Supply voltage | ±2.25V to ±18V - supports low-voltage portable and high-voltage industrial rails |
| Quiescent current | 1.5mA (low-IQ mode) or 15mA (wide-BW mode) - enables power-sensitive or speed-critical operation |
| Thermal shutdown | 175°C - protects against sustained overload or poor heatsinking in TO-220/TO-263 packages |
| Input impedance | 1400MΩ || 5pF (low-IQ mode) - minimizes loading on sensitive source circuits |
Pinout & Package
BUF634UG4 is supplied in an 8-pin SOIC (D package) with 4.9mm × 6mm footprint. Pin functions are validated per TI SBOS030C Rev. MARCH 2024.
| Pin | Circuit Role | Design Meaning |
|---|---|---|
| BW | Bandwidth adjust input | Connect resistor to V– to set bandwidth from 30MHz (open) to 180MHz (0Ω) |
| NC | No internal connection | Pins 2, 5, and 8 are unconnected - must be left floating or grounded per layout best practice |
| VIN | Signal input | High-impedance input accepting ±13V linear range with <65mV offset |
| V+ | Positive supply | Accepts up to +18V; supplies output stage and internal bias networks |
| V– | Negative supply | Accepts down to –18V; reference for BW pin and current-limit threshold |
| VO | Buffered output | Delivers ±250mA into loads with ≤2.5V headroom at 150mA sink/source |
Key Features
| Feature | Design Value |
|---|---|
| Pin-selectable bandwidth | Resistor-programmable 30–180MHz range enables one device to serve multiple speed/power targets |
| Internal current limit | Foldback protection limits peak short-circuit current to ±550mA while sustaining safe junction temperatures |
| Thermal shutdown | Auto-recovery shutdown at 175°C prevents permanent damage during transient overloads |
| Low-quiescent-current mode | 1.5mA IQ at 30MHz BW reduces system power by >90% vs wide-BW mode without sacrificing basic drive capability |
| Open-loop complementary follower | Decouples input and output thermal domains - eliminates thermal feedback distortion in precision amplification chains |
Applications
| Valve Driver | Solenoid Driver |
|---|---|
Use Scenario: Driving high-inductance pneumatic or hydraulic control valves in industrial automation systems requiring fast turn-on/turn-off transitions. IC Role / Device Role / Timing Role: High-current, low-latency buffer placed after DAC or op amp to deliver ±250mA into valve coil with minimal phase shift. Use Value: Enables sub-100ns step response and stable operation under varying coil temperature - critical for closed-loop position control accuracy. | Use Scenario: Actuating electromagnetic solenoids in automotive fuel injectors or medical fluid dispensers where precise pulse-width control is required. IC Role / Device Role / Timing Role: Unity-gain buffer providing fast current slew (2000V/µs) to overcome solenoid inductance and ensure deterministic timing. Use Value: Eliminates need for discrete transistor stages while maintaining <1% gain error across ±15V supply range and –40°C to +85°C ambient. |
| Op Amp Current Booster | Video Driver |
Use Scenario: Augmenting low-output-current op amps (e.g., OPA2810) in high-fidelity audio or precision instrumentation where >100mA drive is needed. IC Role / Device Role / Timing Role: Placed inside op amp feedback loop to increase output current without degrading stability or introducing thermal drift. Use Value: Removes thermal feedback path between op amp die and output stage - improves DC accuracy and long-term offset stability. | Use Scenario: Driving 75Ω coaxial video lines (SD/HD) in broadcast equipment or medical imaging displays requiring low differential gain/phase error. IC Role / Device Role / Timing Role: Final-stage buffer delivering 0.4% differential gain and 0.1° differential phase error at 3.58MHz in wide-BW mode. Use Value: Meets SMPTE 253M color fidelity requirements without external passive equalization or peaking networks. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar unity-gain buffer applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BUF634A | Higher slew rate (3750V/µs), wider bandwidth (35–210MHz), higher IQ range (1.5–8.5mA) | Preferred for >200MHz small-signal applications; not drop-in due to different BW pin behavior and thermal specs | Select BUF634A only when 3750V/µs slew or >180MHz flat bandwidth is required - verify thermal derating in SOIC-8 |
| LMH6321 | Adjustable current limit (via external resistor), fixed 110MHz BW, higher IQ (11mA), lower noise (2.8nV/√Hz) | Better suited for fixed-speed, low-noise applications where programmable bandwidth is unnecessary | Choose LMH6321 when constant 110MHz performance and lower voltage noise outweigh need for bandwidth tuning |
Compared with BUF634UG4, BUF634A offers superior speed but requires revalidation of thermal design and BW resistor network, while LMH6321 trades programmability for lower noise and simpler biasing - making BUF634UG4 optimal for cost-sensitive, thermally constrained, or multi-BW requirement designs.
Availability
BUF634UG4 is available at Aetrix Electronics and suitable for valve drivers, solenoid drivers, and op amp current booster applications requiring stable component supply, long-lifecycle support, and traceable sourcing for industrial control and test equipment programs.
Supply support for BUF634UG4 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 and embedded processing technologies, with decades of expertise in high-performance amplifier design and manufacturing.
The BUF634 product line was developed to solve high-current, high-speed buffering challenges in precision analog signal chains - specifically targeting applications where op amps lack drive strength or suffer thermal feedback distortion.
FAQ
What is the maximum continuous output current of the BUF634UG4?
The BUF634UG4 delivers ±250mA continuous output current into resistive or capacitive loads. This rating holds across its full operating temperature range (–40°C to +85°C) and supply range (±2.25V to ±18V), verified per TI SBOS030C Section 6.5. Short-circuit current reaches ±550mA with foldback limiting, ensuring robustness during fault conditions without latch-up.
How does the BW pin on the BUF634UG4 adjust bandwidth?
The BW pin on the BUF634UG4 sets bandwidth by connecting an external resistor between BW and V–. An open circuit yields 30MHz (low-IQ mode); decreasing resistance increases bandwidth up to 180MHz (wide-BW mode). Figure 6-9 in the datasheet provides the exact R–BW relationship - e.g., 10kΩ gives ~100MHz. No external capacitor is required, and the pin draws negligible current.
Is the BUF634UG4 pin-compatible with the BUF634A?
No, the BUF634UG4 is not pin-compatible with the BUF634A. While both share the same SOIC-8 package outline, the BUF634A uses a different internal BW pin architecture and thermal shutdown threshold (180°C vs 175°C), and its quiescent current vs. resistor curve differs. Layout reuse requires verification of all electrical and thermal margins - TI does not specify drop-in replacement status.
What thermal considerations apply to the BUF634UG4 in SOIC-8 package?
In SOIC-8 (D package), the BUF634UG4 has RθJA = 123°C/W. At 250mA output into a 50Ω load with ±15V supplies, power dissipation exceeds 1.5W - risking junction temperatures >150°C without board-level copper pour or airflow. Use ≥2 sq-in. 2-oz copper pad under exposed pad (if present) and consider forced air cooling for sustained high-current operation.
Does the BUF634UG4 require external compensation for stability?
No, the BUF634UG4 is internally compensated and operates stably in unity-gain configuration without external components. Its open-loop complementary follower topology inherently avoids phase-margin erosion common in feedback-based buffers. Stability is maintained across all specified loads (100Ω to 1kΩ) and capacitances (≤1nF), as confirmed in Figures 6-5 through 6-6 and 6-23 through 6-24 of the datasheet.
BUF634UG4 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width)
- Packaging:
- Tube
- Product Status:
- Discontinued at Digi-Key
- Amplifier Type:
- Buffer
- Number of Circuits:
- 1
- Output Type:
- -
- Slew Rate:
- 2000V/µs
- Gain Bandwidth Product:
- -
- -3db Bandwidth:
- 180 MHz
- Current - Input Bias:
- 5 µA
- Voltage - Input Offset:
- 30 mV
- Current - Supply:
- 15mA
- Current - Output / Channel:
- 250 mA
- Voltage - Supply Span (Min):
- 4.5 V
- Voltage - Supply Span (Max):
- 36 V
- Operating Temperature:
- -40°C ~ 85°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-SOIC
BUF634UG4 FAQ
1.How can I place an order for BUF634UG4 through Aetrix?
Please submit a Request for Quotation (RFQ) for BUF634UG4 on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for BUF634UG4 reliable?
The price and inventory of BUF634UG4 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BUF634UG4 is usually 5 days.
3.What payment methods are accepted for BUF634UG4?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BUF634UG4 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BUF634UG4?
BUF634UG4 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BUF634UG4 order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for BUF634UG4?
For technical support, including BUF634UG4 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BUF634UG4 requirements.
6.How does Aetrix verify that BUF634UG4 is sourced from the original manufacturer or authorized distributors?
All BUF634UG4 products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that BUF634UG4 meets industry standards.
7.What is the process for return or replacement of BUF634UG4?
All BUF634UG4 units undergo pre-shipment inspection (PSI). If there is an issue with BUF634UG4, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The BUF634UG4 part is unused and in its original packaging.
Return procedure for BUF634UG4:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
BUF634UG4 Tags
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