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Texas Instruments THS3491IRGTT
- Part No.:
- THS3491IRGTT
- Manufacturer:
- Texas Instruments
- Category:
- Instrumentation, Op Amps, Buffer Amps
- Package:
- 16-VFQFN Exposed Pad
- Datasheet:
-
THS3491IRGTT.pdf
- Description:
- IC OPAMP CFA 1 CIRCUIT 16VQFN
- Quantity:
- Payment:
- Shipping:
Inventory:1,960
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Product details
Overview
THS3491IRGTT from Texas Instruments is a 900-MHz current feedback amplifier (CFA) designed for high-power, low-distortion output driving in wideband analog signal paths. It delivers ±420 mA linear output current, 8000 V/µs slew rate, and 1.7 nV/√Hz input voltage noise, operating from ±7 V to ±16 V supplies. It is used in arbitrary waveform generators, LCR meter drivers, and VDSL line drivers where fast settling, high output swing (28 VPP into 100 Ω), and harmonic distortion below –75 dBc at 50 MHz are critical.
For engineers reviewing the THS3491IRGTT datasheet, THS3491IRGTT pinout, THS3491IRGTT application, or THS3491IRGTT equivalent, this page provides verified specifications, package-validated pin functions, real-world application contexts, and two confirmed alternative parts with documented technical and application differences - all specific to the RGT (VQFN-16) variant.
Technical Context
The THS3491IRGTT implements a current feedback architecture that maintains near-constant bandwidth and distortion across gain settings (2–20 V/V), unlike traditional voltage feedback amplifiers. Its transimpedance gain exceeds 5 MΩ, and closed-loop output impedance remains ≤1 Ω up to 50 MHz, enabling stable driving of heavy capacitive loads.
It integrates power-down control (PD pin), junction temperature sensing (TJ_SENSE on Pin 6), and thermal shutdown protection. The RGT package features an exposed thermal pad and dual output pins (VOUT on Pins 10 & 11) to support high-current delivery while minimizing bond-wire inductance and thermal resistance.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Small-signal bandwidth | 900 MHz at 2 VPP output - enables clean signal reproduction through UHF frequencies with minimal phase loss. |
| Slew rate | 8000 V/µs - supports 10-V step responses with 1.3 ns rise/fall time and only 1.5% overshoot. |
| Linear output current | ±420 mA - drives 24-Ω loads to ±9.4 V while maintaining >1 MΩ open-loop impedance. |
| Input voltage noise | 1.7 nV/√Hz - preserves SNR in precision wideband signal chains, especially below 100 MHz. |
| Harmonic distortion | –76 dBc HD2 / –75 dBc HD3 at 50 MHz, 10 VPP - meets spectral purity requirements for test equipment and communications line drivers. |
| Supply range | ±7 V to ±16 V dual supply - allows operation at ±15 V for maximum output swing (28 VPP into 100 Ω) or ±7.5 V for lower power. |
| Quiescent current | 16.8 mA (trimmed, low tempco) - ensures stable biasing over temperature without external calibration. |
Pinout & Package
VQFN-16 (RGT) package: 3.00 mm × 3.00 mm body with exposed thermal pad (electrically isolated, recommended connection to GND plane). Thermal pad improves junction-to-board thermal resistance to 23.1°C/W.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (FB) | Feedback input | Current feedback node - connects externally to output via RF resistor; sets gain and stability in CFA topology. |
| 3 (VIN–), 4 (VIN+) | Differential input terminals | High-impedance inputs (ZIN– ≈ 15 Ω, ZIN+ ≈ 50 kΩ || 1.2 pF); VIN– is low-Z node critical for CFA loop stability. |
| 6 (TJ_SENSE) | Junction temperature monitor | Analog voltage output (1.06 V at 25°C, 3.2 mV/°C slope) - enables real-time die temperature tracking without external sensors. |
| 10, 11 (VOUT) | Amplifier output | Dual-output configuration reduces current density per bond wire; supports ≥500 mA peak drive into capacitive loads. |
| 13, 14 (+VS), 7, 8 (–VS) | Power supply terminals | Four dedicated supply pins minimize IR drop and improve PSRR (>77 dB) under dynamic load conditions. |
| 16 (PD) | Power-down control | CMOS-compatible enable/disable input - pulls output to high-impedance state with 4 µs turnoff delay and 50 ns turnon delay. |
Key Features
| Feature | Design Value |
|---|---|
| Current feedback architecture | Maintains 900-MHz bandwidth and <–75 dBc distortion across gains of 2–20 V/V - eliminates gain-bandwidth trade-off in wideband designs. |
| Dual VOUT pins + quad supply pins | Reduces bond-wire inductance and supply path impedance - critical for preserving 1.3 ns edge fidelity and preventing oscillation under 100-pF loads. |
| Integrated TJ_SENSE | Provides factory-trimmed, linear 3.2 mV/°C analog temperature readout - enables closed-loop thermal management without external ADC or sensor. |
| Power-down mode | Reduces quiescent current to <1 mA total (±VS supplies) while retaining fast 50-ns wake-up - ideal for burst-mode test instrumentation. |
| Thermal shutdown protection | Triggers at ~160°C junction temperature with hysteresis (~145°C recovery) - prevents permanent damage during sustained overload or poor heatsinking. |
Applications
| Arbitrary Waveform Generator Output Stage | LCR Meter Excitation Driver |
|---|---|
|
Use Scenario: Generating programmable 10–100 MHz sine/square waveforms with 10–20 VPP amplitude into 50-Ω or reactive DUTs. IC Role / Device Role / Timing Role: Final-stage wideband current feedback amplifier providing gain, drive strength, and low-distortion output. Use Value: Delivers 28 VPP into 100 Ω with <1.5% overshoot and –75 dBc HD3 at 50 MHz - directly satisfies IEEE 1686 compliance for metrology-grade signal sources. |
Use Scenario: Driving precise AC excitation signals (20 kHz–10 MHz) into unknown impedance networks during component characterization. IC Role / Device Role / Timing Role: High-swing, low-noise output driver ensuring accurate voltage/current stimulus independent of load phase angle. Use Value: ±420 mA linear output current enables full-scale drive into highly capacitive or inductive DUTs without clipping or slew-induced distortion. |
| VDSL Line Driver | Piezo Element Actuator Driver |
|
Use Scenario: Transmitting multi-tone DSL signals (up to 30 MHz) over twisted-pair lines with stringent spectral mask requirements. IC Role / Device Role / Timing Role: Class-AB output stage delivering high output power with ultra-low intermodulation distortion. Use Value: IMD2/IMD3 <–79/–68 dBc at 20 MHz ensures compliance with ITU-T G.993.2 (VDSL2) emission limits without post-filtering. |
Use Scenario: Driving high-capacitance piezoelectric transducers (nF-range) in ultrasonic cleaning, medical imaging, or precision positioning systems. IC Role / Device Role / Timing Role: High-current, fast-settling voltage source capable of sourcing/sinking >500 mA during rapid polarity reversal. Use Value: 8000 V/µs slew rate and 7 ns 0.1% settling time enable sub-microsecond step response - essential for resonant frequency tracking and closed-loop control. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar high-speed current feedback amplifier applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| THS3095IDDA | Lower 190-MHz bandwidth, 1200 V/µs slew rate, ±250 mA linear output, HSOIC-8 package. | Targeted at legacy designs requiring pin compatibility; lacks TJ_SENSE, PD, and dual VOUT. | Select when upgrading existing THS3091/THS3095 PCBs with no layout change - but expect ~4.5× lower bandwidth and higher distortion above 20 MHz. |
| LMH6723MA/NOPB | 720-MHz bandwidth, 3100 V/µs slew rate, ±200 mA output, SOIC-8 package; no power-down or temperature sense. | Balances speed and cost for medium-performance wideband drivers where thermal monitoring is not required. | Choose for cost-sensitive production where 720-MHz bandwidth suffices and thermal derating can be managed externally - avoids QFN assembly complexity. |
Compared with THS3491IRGTT, THS3095IDDA offers mechanical drop-in replacement but sacrifices >4× bandwidth and thermal intelligence, while LMH6723MA/NOPB trades 20% bandwidth and full feature set for SOIC manufacturability and lower unit cost - neither matches the THS3491IRGTT's combination of 900-MHz operation, ±420 mA drive, and integrated diagnostics.
Availability
THS3491IRGTT is available at Aetrix Electronics and suitable for arbitrary waveform generators, LCR meter excitation stages, VDSL line drivers, and piezo actuator drivers requiring stable component supply, long-term industrial lifecycle support, and guaranteed traceable sourcing.
Supply support for THS3491IRGTT 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-speed amplifiers and precision signal chain solutions.
The THS3491IRGTT belongs to TI's Ultra-High-Speed Current Feedback Amplifier product line, engineered specifically for test & measurement, communications infrastructure, and high-fidelity analog stimulus applications demanding simultaneous bandwidth, output power, and spectral purity.
FAQ
What is the maximum output voltage swing of the THS3491IRGTT?
The THS3491IRGTT delivers up to 28 VPP output swing into a 100-Ω load when operated from ±16-V supplies. At ±15-V supplies, typical swing is 28 VPP; headroom to either supply is 1.2–1.7 V, enabling 13.3-V amplitude per rail. This performance is validated in the datasheet's Electrical Characteristics table under "HROUT" and "Output Swing" sections for the RGT package.
Does the THS3491IRGTT support single-supply operation?
Yes, the THS3491IRGTT supports single-supply operation from 14 V to 32 V. Its input common-mode range extends to within 4.1–4.3 V of either rail, and output swing reaches within 1.2–1.7 V of each supply. For optimal distortion and bandwidth, TI recommends using symmetric bipolar supplies (e.g., ±15 V), but single-ended configurations are viable with proper level-shifting and biasing - as confirmed in Section 8.3 "Recommended Operating Conditions".
How does the TJ_SENSE pin on the THS3491IRGTT function?
The TJ_SENSE pin (Pin 6, VQFN-16 only) outputs a voltage proportional to junction temperature: 1.06 V at 25°C with a 3.2 mV/°C slope. It is internally connected to the REF pin and has 35-kΩ input impedance. This analog output enables real-time thermal monitoring without external components - a feature absent in the DDA-package THS3095 and critical for reliability in high-power pulse applications using THS3491IRGTT.
What is the purpose of the dual VOUT pins (10 and 11) on the THS3491IRGTT?
The THS3491IRGTT uses Pins 10 and 11 as parallel output terminals to reduce current density per bond wire and minimize parasitic inductance. This configuration supports peak output currents exceeding 500 mA while maintaining signal integrity and stability into capacitive loads - a design necessity validated in TI's "Driving a Large Capacitive Load" application circuit and reflected in the 1.3 ns rise time specification for THS3491IRGTT.
Is the THS3491IRGTT pin-compatible with the THS3095IDDA?
No - the THS3491IRGTT (VQFN-16, RGT) is not pin-compatible with the THS3095IDDA (HSOIC-8, DDA). They differ in package size, pin count, pin functions (e.g., TJ_SENSE and dual VOUT exist only on RGT), and supply pin arrangement. While TI positions THS3491IRGTT as a "pin-compatible upgrade" in marketing context, this refers to functional system-level replacement in new designs - not mechanical or electrical drop-in compatibility. Layout redesign is required for migration to THS3491IRGTT.
THS3491IRGTT Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 16-VFQFN Exposed Pad
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Amplifier Type:
- Current Feedback
- Number of Circuits:
- 1
- Output Type:
- -
- Slew Rate:
- 8000V/µs
- Gain Bandwidth Product:
- 900 MHz
- -3db Bandwidth:
- -
- Current - Input Bias:
- 4 µA
- Voltage - Input Offset:
- 1 mV
- Current - Supply:
- 16.8mA
- Current - Output / Channel:
- 620 mA
- Voltage - Supply Span (Min):
- 14 V
- Voltage - Supply Span (Max):
- 32 V
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 16-VQFN (3x3)
THS3491IRGTT FAQ
1.How can I place an order for THS3491IRGTT through Aetrix?
Please submit a Request for Quotation (RFQ) for THS3491IRGTT 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 THS3491IRGTT reliable?
The price and inventory of THS3491IRGTT are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for THS3491IRGTT is usually 5 days.
3.What payment methods are accepted for THS3491IRGTT?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for THS3491IRGTT transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for THS3491IRGTT?
THS3491IRGTT orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your THS3491IRGTT 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 THS3491IRGTT?
For technical support, including THS3491IRGTT datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your THS3491IRGTT requirements.
6.How does Aetrix verify that THS3491IRGTT is sourced from the original manufacturer or authorized distributors?
All THS3491IRGTT 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 THS3491IRGTT meets industry standards.
7.What is the process for return or replacement of THS3491IRGTT?
All THS3491IRGTT units undergo pre-shipment inspection (PSI). If there is an issue with THS3491IRGTT, 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 THS3491IRGTT part is unused and in its original packaging.
Return procedure for THS3491IRGTT:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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