THS3125ID Equivalent & Substitute Parts

Part Overview

The THS3125ID is a current feedback amplifier integrated circuit manufactured by Texas Instruments, configured with 2 circuits in a 14-SOIC surface mount package. This device is classified as a Last Time Buy product, indicating discontinued production with limited inventory availability. The THS3125ID delivers high-speed amplification with a slew rate of 1550V/µs and gain bandwidth product of 138 MHz, suitable for applications requiring fast signal processing and wide bandwidth performance. Due to its Last Time Buy status, identifying equivalent substitute components is essential for design continuity and long-term supply chain planning.

Substiute Parts

THS3125ID

Texas InstrumentsIn Stock: 2166THS3125ID Datasheet

Current PartRFQ

THS3115ID

Texas InstrumentsIn Stock: 1164THS3115ID Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the THS3125ID is determined by strict alignment of electrical and mechanical parameters within the current feedback amplifier category. The primary substitution criteria are:

Mechanical Compatibility: Both the main part and substitute must share identical package specifications (14-SOIC surface mount) and physical dimensions to ensure direct board-level replacement without layout modifications.

Electrical Core Parameters: Substitutes must maintain the same amplifier topology (current feedback), circuit count (2 circuits), and supply voltage range (10V to 30V minimum and maximum) to ensure functional equivalence in the target application.

Performance Characteristics: The slew rate of 1550V/µs and operating temperature range of -40°C to 85°C establish the baseline performance envelope. Substitutes meeting or exceeding these specifications remain functionally compatible.

Compliance & Certification: All substitute parts must maintain ROHS3 compliance, MSL Level 1 rating, and REACH unaffected status to satisfy regulatory and environmental requirements.

The THS3115ID qualifies as a manufacturer-recommended substitute based on full alignment with these criteria, despite variations in secondary parameters such as input bias current, input offset voltage, and supply current.

Parameter Comparison

Engineering Selection Recommendations

The THS3115ID is the manufacturer-recommended substitute for the THS3125ID. Selection of the THS3115ID is supported by the following engineering factors:

Product Status & Availability: The THS3125ID carries Last Time Buy status, indicating end-of-life production. The THS3115ID maintains Active product status with confirmed inventory availability, ensuring reliable long-term supply for new designs and production continuity.

Regulatory Compliance: Both devices maintain identical ROHS3 compliance, MSL Level 1 rating, and REACH unaffected status, satisfying all environmental and regulatory requirements without additional qualification.

Mechanical Interchangeability: Both parts utilize the 14-SOIC surface mount package with identical physical dimensions (0.154" width, 3.90mm), enabling direct board-level substitution without PCB layout modifications.

Electrical Compatibility: Both devices operate within the same supply voltage range (10V to 30V) and temperature envelope (-40°C to 85°C), maintaining functional equivalence across the specified operating conditions.

Performance Trade-offs: The THS3115ID exhibits reduced -3dB bandwidth (110 MHz versus 160 MHz), lower input bias current (0.33 µA versus 6 µA), lower input offset voltage (3 mV versus 4.4 mV), and reduced supply current (4.9 mA versus 8.4 mA). These characteristics result in improved precision and reduced power consumption, making the THS3115ID suitable for applications where the lower bandwidth specification remains acceptable.

Frequently Asked Questions (FAQ)

Q: Can the THS3115ID directly replace the THS3125ID on existing PCBs?

A: Yes. Both devices share identical 14-SOIC surface mount packaging and physical dimensions. Direct board-level substitution is possible without PCB layout modifications. However, circuit performance will reflect the THS3115ID's electrical characteristics, particularly the reduced -3dB bandwidth of 110 MHz compared to the THS3125ID's 160 MHz.

Q: What are the key electrical differences between these two parts?

A: The primary differences are -3dB bandwidth (160 MHz for THS3125ID versus 110 MHz for THS3115ID), input bias current (6 µA versus 0.33 µA), input offset voltage (4.4 mV versus 3 mV), and supply current per channel pair (8.4 mA versus 4.9 mA). Both maintain identical slew rate (1550V/µs) and supply voltage range (10V to 30V).

Q: Why is the THS3125ID classified as Last Time Buy?

A: Last Time Buy status indicates that Texas Instruments has discontinued production of this device. Existing inventory is available for purchase, but no future production runs are planned. The THS3115ID is the recommended active alternative for new designs.

Q: Are there any compliance or certification differences between these parts?

A: No. Both devices maintain identical ROHS3 compliance, MSL Level 1 moisture sensitivity rating, and REACH unaffected status. No additional qualification or testing is required from a regulatory perspective.

Q: Which part should be selected for new designs?

A: The THS3115ID should be selected for new designs due to its Active product status and assured long-term availability. The THS3125ID should be reserved for legacy design support or applications requiring its specific 160 MHz bandwidth specification where the THS3115ID's 110 MHz bandwidth is insufficient.

Q: What is the impact of the reduced -3dB bandwidth in the THS3115ID?

A: The THS3115ID's -3dB bandwidth of 110 MHz is lower than the THS3125ID's 160 MHz. Applications requiring signal processing or amplification above 110 MHz may experience reduced performance. Applications operating within the 110 MHz bandwidth specification will function identically.

Q: Are both parts available in the same packaging options?

A: Both devices are available exclusively in 14-SOIC surface mount packaging. No alternative package options exist for either part number.