THS4221D - 230MHz High-Speed Rail-to-Rail Op Amp | Texas Instruments
MPN: THS4221D ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $0 | $0.00 |
| 10 | $0 | $0.00 |
| 100 | $0 | $0.00 |
| 500 | $0 | $0.00 |
| 1,000 | $0 | $0.00 |
THS4221D Overview
An operational amplifier is an analog signal-conditioning semiconductor that uses high open-loop gain to amplify differences between input signals. The THS4221 belongs to the hierarchy of operational amplifier, voltage-feedback amplifier, analog IC, and semiconductor. Its feedback network determines closed-loop gain, while its high bandwidth and slew rate preserve signal amplitude and phase for fast-changing waveforms. Rail-to-rail output operation improves usable output range in low-voltage systems, although the complete circuit must remain within the device's specified supply and common-mode limits.
Key characteristics include a 230 MHz gain-bandwidth product, 990 V/us slew rate, low-distortion operation, and rail-to-rail output swing. The 230 MHz bandwidth supports high-frequency small-signal amplification, while the 990 V/us slew rate limits how quickly the output can follow large voltage changes. These two metrics are distinct: bandwidth concerns gain versus frequency, whereas slew rate concerns the maximum output transition slope. Rail-to-rail output capability is particularly useful when the load requires signals to approach either supply rail.
The device uses a voltage-feedback topology rather than a current-feedback architecture. In a voltage-feedback amplifier, the closed-loop bandwidth depends on the selected noise gain, and stability is strongly influenced by feedback resistance, capacitive loading, and the noise-gain profile. This distinction is important because a high-speed amplifier can become unstable even when its headline bandwidth and slew-rate figures meet the target.
Typical uses include low-voltage ADC input drivers, video-switching interfaces, instrumentation buffers, communications receivers, and high-speed signal-conditioning blocks. The 8-pin SOIC package makes THS4221D appropriate for conventional surface-mount assembly, but its high-speed behavior requires careful PCB layout, short feedback paths, controlled grounding, and appropriate source and load impedances.
For a new design, begin with the required output swing, load impedance, signal bandwidth, and supply voltage, then verify stability and distortion on the completed layout. Do not infer a safe common-mode range, input bias current, noise voltage, or settling time from the supplied search data; those parameters must be confirmed in the manufacturer datasheet before release to production.
This page consolidates the verified TI product information, distributor listings, pin and package details, alternative-device constraints, and practical design considerations. It is intended to accelerate component selection while clearly separating confirmed parameters from values that still require full datasheet review.
Drop-in alternatives for THS4221D — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
THS4225D
✅ Drop-In📋 Reference alternative (not in catalog)
THS4221DGN
✅ Drop-In📋 Reference alternative (not in catalog)
THS4221D Maximum Ratings & Electrical Characteristics
| Amplifier Type | Single voltage-feedback operational amplifier |
| Topology | Voltage feedback |
| Gain-Bandwidth Product | 230 MHz at -3 dB |
| Slew Rate | 990 V/us |
| Supply Voltage Range | ±1.35 V to ±7.5 V |
| Output Type | Rail-to-rail output |
| Number of Amplifiers | 1 circuit |
| Package | 8-pin SOIC (D) |
| Pin Count | 8 pins |
| Mounting Type | Surface mount |
| Operating Temperature Range | -40°C to +85°C |
| Signal Type | Analog |
| Primary Applications | Data converter driving, video switching, and low-distortion signal conditioning |
| Distributor Availability Signal | DigiKey listing states buy now and ships today |
THS4221D 8-pin soic (d) Pin Configuration Guide
Pin configuration for THS4221D (8-pin soic (d) package). This analog component features input, output, and power supply pins. Refer to the manufacturer datasheet for offset null, compensation, and enable pin configurations. Ideal for signal conditioning and amplifier circuits.
No detailed pinout data available for THS4221D.
Refer to the datasheet for full pin configuration.
Typical Applications
THS4221D is suitable for 6 applications: High-Speed ADC Input Driver, Video Switching Interface, Communications Receiver, Precision Instrumentation Buffer, Data Converter Output Buffer, Test and Measurement Front End.
High-Speed ADC Input Driver
The THS4221D fits low-voltage ADC front ends that require a 230 MHz -3 dB bandwidth and 990 V/us slew rate. Its low-distortion voltage-feedback architecture can amplify a high-frequency differential signal into the converter's input range, while rail-to-rail output improves usable swing at low supply voltages. Place the device close to the ADC, minimize routing between the amplifier and converter, and verify settling against the converter's bit-resolution requirement. The principal trade-off is that a wide-band amplifier can amplify high-frequency noise and expose board-level stability issues, so source impedance, feedback values, and input termination must be selected from the manufacturer guidance.
Recommended
Video Switching Interface
The THS4221D is suitable for video-switching buffers where the 230 MHz bandwidth and 990 V/us slew rate can preserve rapidly changing transitions. Rail-to-rail output operation is useful in compact systems with limited supply headroom, while the single-channel 8-pin SOIC package supports straightforward routing. The circuit should use short traces, a continuous ground plane, and decoupling placed near the supply pins to minimize edge-rate artifacts. Video amplitude, settling time, channel isolation, and allowable gain are not present in the supplied excerpts and must be verified from the datasheet before selecting resistor values or considering it for standard-definition versus high-definition formats.
Recommended
Communications Receiver
The high-speed voltage-feedback THS4221D can provide gain and impedance conditioning in low-voltage communications receiver paths. Its 230 MHz gain-bandwidth product supports high-frequency baseband or IF-related amplification, and its 990 V/us slew rate provides large-signal response beyond what many general-purpose amplifiers offer. Rail-to-rail output helps maximize signal swing when the downstream receiver has a restricted input range. Designers must still account for noise, input bias current, common-mode range, and output impedance, none of which are confirmed in the provided search excerpts, and should validate gain flatness and stability across the complete operating frequency range.
Recommended
Precision Instrumentation Buffer
The THS4221D can serve as the active element in a wideband instrumentation or measurement amplifier stage when low distortion and fast settling are more important than micropower operation. The 230 MHz bandwidth allows small signals to be amplified without excessive closed-loop attenuation, and the 990 V/us slew rate improves response to rapidly changing sensor waveforms. Rail-to-rail output helps preserve measurement amplitude in low-voltage systems. Because input offset, input bias current, noise density, and common-mode limits are absent from the verified excerpts, those parameters must be checked before using it with high-impedance sensors. Feedback-network impedance and sensor capacitance also require stability review.
Recommended
Data Converter Output Buffer
The THS4221D can buffer a data-converter output when the receiving circuit requires rail-to-rail swing, low distortion, and fast edge response. Its 990 V/us slew rate reduces the chance that large output transitions become slew-limited, while the 230 MHz -3 dB bandwidth supports wideband signal paths. The SOIC-8 package is practical for conventional surface-mount assembly. Correct usage depends on the source impedance and load capacitance; excessive capacitive loading can destabilize a high-speed voltage-feedback amplifier. Keep feedback and output routing compact, use local supply bypassing, and compare the converter's output settling and glitch requirements with the amplifier's verified datasheet limits before release.
Recommended
Test and Measurement Front End
The THS4221D is appropriate for a high-speed test-and-measurement front end when the source is low impedance and the desired bandwidth approaches or exceeds 230 MHz. Rail-to-rail output supports instrumentation powered from low-voltage rails, and the high slew rate preserves the amplitude of fast waveforms. The amplifier should be placed near the measurement device, with controlled source impedance and short feedback paths. A terminated 50-ohm environment may be preferable for wideband signal-chain accuracy, depending on the desired circuit topology. The verified excerpts do not specify noise, offset, settling time, or input impedance, so those parameters require confirmation before defining measurement uncertainty or instrument accuracy.
Recommended
Recommended Products Summary
Engineering reference data for THS4221D — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | THS4225D | THS4221DGN |
|---|---|---|---|
| Package | SOIC-8 (D) | SOIC-8 (D) | SOIC-8 (D) |
| Brand | Texas Instruments | Texas Instruments | Texas Instruments |
Key Differentiators
- Higher bandwidth than the THS4031 cited in the verified comparison (vs THS4031)
- Faster large-signal response than the THS4031 cited in the verified comparison (vs THS4031)
- Rail-to-rail output supports low-voltage signal-chain designs (vs THS4031)
Design Notes
Keep the THS4221D feedback components and their ground returns close to the device pins, and minimize the distance between the amplifier and the ADC or video load. Place supply bypassing near the amplifier rather than at the power source. At 990 V/us, even short PCB inductance and capacitance can create edge-rate artifacts, so route the high-speed signal over a continuous ground plane and avoid nearby switching nodes.
Do not treat the ±1.35 V to ±7.5 V supply range as proof that every input and output condition is valid at the rail limits. Confirm the common-mode range, output swing, settling time, and stability requirements from the manufacturer datasheet. The THS4221D is a voltage-feedback amplifier, so changing feedback resistance or noise gain can materially affect bandwidth and oscillation margin; validate the final resistor and capacitor values on the assembled layout.
Control source and load impedances because high-speed voltage-feedback amplifiers can lose stability when driving capacitive loads or working with high source resistance. Add isolation resistors only when their effect on gain and bandwidth has been calculated. If the application is a video or communications line, compare the required bandwidth with the stated 230 MHz -3 dB figure and verify that the receiver does not require a larger unattenuated passband.
High slew rate can couple energy into adjacent circuits even when the intended signal is low frequency. Keep the amplifier away from switching regulators and digital clocks, maintain a compact output path, and use a solid ground reference. If the output drives a cable or long PCB trace, use a series termination resistor and evaluate edge reflections at the target bandwidth; do not rely on the nominal 230 MHz gain-bandwidth value as a guarantee of acceptable EMI.
Compliance Information
The supplied TI, DigiKey, Mouser, FindIC, and AllDatasheet excerpts do not explicitly state THS4221D compliance status. Compliance fields remain unknown rather than inferred from package type or manufacturer identity.
