THS3091DDA Equivalent & Substitute Parts

Part Overview

The THS3091DDA is a current feedback amplifier integrated circuit manufactured by Texas Instruments, housed in an 8-PowerSOIC surface mount package. This device is classified as a Last Time Buy product, indicating that it is no longer in active production. The THS3091DDA delivers high-speed amplification with a slew rate of 7300 V/µs and -3dB bandwidth of 235 MHz, making it suitable for high-frequency signal conditioning applications.

Due to its Last Time Buy status, identifying equivalent and substitute parts is necessary for design continuity and long-term component availability. Substitute parts are selected based on matching electrical performance parameters, package compatibility, and operational specifications that allow direct or near-direct replacement in existing circuit designs.

Substiute Parts

THS3091DDA

Texas InstrumentsIn Stock: 108384THS3091DDA Datasheet

Current PartRFQ

THS3091DDAR

Texas InstrumentsIn Stock: 2317THS3091DDAR Datasheet

MFR RecommendedRFQ

LT1228CS8#PBF

Analog Devices Inc.In Stock: 1406LT1228CS8#PBF Datasheet

MFR RecommendedRFQ

LT1228CS8#TRPBF

Analog Devices Inc.In Stock: 1501LT1228CS8#TRPBF Datasheet

MFR RecommendedRFQ

LT1228IS8#PBF

Analog Devices Inc.In Stock: 27895LT1228IS8#PBF Datasheet

MFR RecommendedRFQ

LT1228IS8#TRPBF

Analog Devices Inc.In Stock: 1072LT1228IS8#TRPBF Datasheet

MFR RecommendedRFQ

LT1252CS8#PBF

Analog Devices Inc.In Stock: 1196LT1252CS8#PBF Datasheet

MFR RecommendedRFQ

LT1252CS8#TRPBF

Analog Devices Inc.In Stock: 1089LT1252CS8#TRPBF Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the THS3091DDA is determined by the following critical parameters:

Primary Substitution Criteria:

• Amplifier Type: Current Feedback
• Number of Circuits: 1
• Package Compatibility: 8-SO or 8-PowerSOIC surface mount packages
• Operating Temperature Range: Minimum -40°C to 85°C
• Supply Voltage Range: Minimum 10 V to 30 V span
• RoHS3 Compliance and MSL Level 1 rating

Performance Parameters for Functional Equivalence:

• Slew Rate: 7300 V/µs (primary specification)
• -3dB Bandwidth: 235 MHz (primary specification)
• Current - Output / Channel: 280 mA (primary specification)
• Input Bias Current: 4 µA
• Input Offset Voltage: 900 mV

Substitute parts are grouped into two categories:

Category 1: Direct Packaging Equivalent The THS3091DDAR maintains identical electrical specifications and packaging as the THS3091DDA, differing only in packaging format (Cut Tape & Digi-Reel versus Tube). This part is the primary recommended substitute.

Category 2: Functional Substitutes with Performance Trade-offs The LT1228 and LT1252 series from Analog Devices Inc. are current feedback amplifiers with compatible package footprints but reduced performance specifications. These parts operate within the same 8-SO package family and maintain RoHS3 compliance and MSL Level 1 ratings. However, they exhibit lower slew rates and bandwidth compared to the THS3091DDA, requiring circuit design evaluation for specific applications.

Parameter Comparison

Engineering Selection Recommendations

Primary Recommendation: THS3091DDAR

The THS3091DDAR is the preferred substitute for the THS3091DDA. This part is manufactured by Texas Instruments and maintains identical electrical specifications, including slew rate (7300 V/µs), bandwidth (235 MHz), output current (280 mA), and supply voltage range (10 V to 30 V). The THS3091DDAR is in Active product status, ensuring long-term availability and supply chain continuity. Both parts are ROHS3 compliant with MSL Level 1 ratings. The only difference is packaging format: THS3091DDAR is supplied in Cut Tape & Digi-Reel format, while THS3091DDA is supplied in Tube format. This substitution requires no circuit redesign.

Secondary Recommendations: LT1228 Series (LT1228CS8#PBF, LT1228CS8#TRPBF, LT1228IS8#PBF, LT1228IS8#TRPBF)

The LT1228 series from Analog Devices Inc. provides functional substitution with reduced performance specifications. These parts maintain current feedback amplifier topology and 8-SOIC package compatibility. The LT1228IS8 variants support the full operating temperature range (-40°C to 85°C) matching the THS3091DDA, while LT1228CS8 variants operate from 0°C to 70°C. All LT1228 variants are in Active product status and ROHS3 compliant with MSL Level 1 ratings.

Performance trade-offs include reduced slew rate (3500 V/µs versus 7300 V/µs) and reduced bandwidth (100 MHz versus 235 MHz). Output current is also reduced to 125 mA versus 280 mA. These parts are suitable for applications where lower bandwidth and slew rate are acceptable.

Tertiary Recommendation: LT1252 Series (LT1252CS8#PBF, LT1252CS8#TRPBF)

The LT1252 series provides an alternative current feedback amplifier with higher bandwidth (282 MHz) but significantly lower slew rate (125 V/µs) and reduced output current (55 mA). These parts are in Active product status and ROHS3 compliant with MSL Level 1 ratings. The LT1252 series is suitable only for applications where bandwidth is prioritized over slew rate performance.

Compliance and Certification:

All recommended substitute parts maintain ROHS3 compliance and MSL Level 1 (Unlimited) moisture sensitivity ratings, ensuring compatibility with standard manufacturing and storage processes. All parts are classified under ECCN EAR99 and HTSUS 8542.33.0001.

Frequently Asked Questions (FAQ)

Q: Can the THS3091DDAR be used as a direct replacement for the THS3091DDA?

A: Yes. The THS3091DDAR is electrically and functionally identical to the THS3091DDA. Both parts share identical specifications for slew rate, bandwidth, output current, supply voltage range, and operating temperature. The only difference is packaging format (Cut Tape & Digi-Reel versus Tube). No circuit modifications are required.

Q: What are the key differences between the THS3091DDA and the LT1228 series?

A: The primary differences are slew rate and bandwidth. The THS3091DDA provides 7300 V/µs slew rate and 235 MHz bandwidth, while the LT1228 series provides 3500 V/µs slew rate and 100 MHz bandwidth. Output current is also reduced in the LT1228 series (125 mA versus 280 mA). The LT1228IS8 variants support the full -40°C to 85°C temperature range, while LT1228CS8 variants operate from 0°C to 70°C. All parts use compatible 8-SO package footprints.

Q: Why is the LT1252 series not recommended as a primary substitute?

A: The LT1252 series exhibits significantly reduced slew rate (125 V/µs) compared to the THS3091DDA (7300 V/µs), making it unsuitable for high-speed signal conditioning applications. Although the LT1252 provides higher bandwidth (282 MHz), the severely limited slew rate creates a fundamental performance mismatch. The LT1252 is suitable only for specific applications where bandwidth is the primary concern and slew rate limitations are acceptable.

Q: Are all substitute parts RoHS compliant?

A: Yes. All recommended substitute parts, including THS3091DDAR, LT1228 series, and LT1252 series, are ROHS3 compliant with MSL Level 1 (Unlimited) moisture sensitivity ratings. All parts are classified as REACH Unaffected.

Q: What is the difference between LT1228CS8 and LT1228IS8 variants?

A: The primary difference is operating temperature range. LT1228CS8 variants operate from 0°C to 70°C, while LT1228IS8 variants operate from -40°C to 85°C. The LT1228IS8 variants match the full temperature range of the THS3091DDA and are recommended for applications requiring extended temperature operation. Both variants are available in Tube (PBF) and Tape & Reel (TRPBF) packaging formats.

Q: What is the difference between packaging formats (Tube, Cut Tape, and Tape & Reel)?

A: Tube packaging supplies components in plastic tubes suitable for manual handling and small-quantity applications. Cut Tape & Digi-Reel packaging supplies components on carrier tape in reel format, optimized for automated assembly equipment. Tape & Reel (TR) packaging supplies components on standard 13-inch reels for high-volume production. All three formats contain identical components; the difference is in delivery and handling method.

Q: Can I use the LT1228 series in a design originally specified for the THS3091DDA?

A: Substitution depends on application requirements. If the design requires the full 7300 V/µs slew rate and 235 MHz bandwidth of the THS3091DDA, the LT1228 series (3500 V/µs, 100 MHz) is not suitable without circuit redesign. If the application can tolerate reduced slew rate and bandwidth, the LT1228 series may be acceptable. The LT1228IS8 variants are preferred over LT1228CS8 variants due to extended temperature range compatibility.

Q: What is the significance of the "Last Time Buy" status for the THS3091DDA?

A: Last Time Buy status indicates that Texas Instruments has discontinued production of the THS3091DDA and will not accept new orders after a specified date. Existing inventory will be depleted, and the part will no longer be available from the manufacturer. This status makes identification of substitute parts essential for long-term design continuity and supply chain planning.

Q: Are there any pin-compatibility issues between the THS3091DDA and substitute parts?

A: The THS3091DDA uses an 8-PowerSOIC package, while the LT1228 and LT1252 series use standard 8-SOIC packages. Although both package types have 8 pins with 0.154-inch (3.90mm) width, the PowerSOIC variant includes an additional thermal pad for enhanced heat dissipation. Pin assignments are compatible for standard signal connections (input, output, supply, ground), but PCB layout modifications may be required to accommodate the different thermal pad configurations.