OPA3684IDRG4 Equivalent & Substitute Parts

Part Overview

The OPA3684IDRG4 is a current feedback amplifier integrated circuit manufactured by Texas Instruments, configured as a 3-circuit operational amplifier in a 14-SOIC surface mount package. This device is classified as discontinued at DiGi Electronics, necessitating identification of active equivalent and substitute components for ongoing design support and procurement requirements. The OPA3684IDRG4 delivers high-speed amplification with a gain bandwidth product of 1.9 GHz and slew rate of 780 V/µs, suitable for applications requiring current feedback topology performance within the specified supply voltage range of 2.8 V to 12 V.

Substiute Parts

OPA3684IDRG4

Texas InstrumentsIn Stock: 1129OPA3684IDRG4 Datasheet

Current PartRFQ

ADA4861-3YRZ

Analog Devices Inc.In Stock: 1397ADA4861-3YRZ Datasheet

MFR RecommendedRFQ

ADA4861-3YRZ-RL7

Analog Devices Inc.In Stock: 18359ADA4861-3YRZ-RL7 Datasheet

MFR RecommendedRFQ

ADA4862-3YRZ

Analog Devices Inc.In Stock: 3655ADA4862-3YRZ Datasheet

MFR RecommendedRFQ

ADA4862-3YRZ-RL

Analog Devices Inc.In Stock: 852ADA4862-3YRZ-RL Datasheet

MFR RecommendedRFQ

ADA4862-3YRZ-RL7

Analog Devices Inc.In Stock: 15778ADA4862-3YRZ-RL7 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the OPA3684IDRG4 is determined by strict adherence to the following electrical and mechanical parameters:

Primary Substitution Criteria:

• Package / Case: 14-SOIC (0.154", 3.90mm Width) — mechanical compatibility requirement
• Mounting Type: Surface Mount — assembly process compatibility
• Number of Circuits: 3 — functional circuit count requirement
• Voltage - Supply Span: Minimum 2.8 V to Maximum 12 V — power supply compatibility

Secondary Compatibility Parameters:

• Amplifier Type: Current Feedback topology (ADA4861 series) or General Purpose topology (ADA4862 series)
• Operating Temperature: -40°C to 85°C minimum coverage
• RoHS3 Compliance and REACH Unaffected status

The substitute parts identified are manufactured by Analog Devices Inc. and maintain the identical 14-SOIC package footprint and surface mount configuration. All substitute parts are active products with unlimited moisture sensitivity rating (MSL 1), providing superior long-term availability compared to the discontinued OPA3684IDRG4.

Parameter Comparison

Engineering Selection Recommendations

Current Feedback Topology Substitutes (ADA4861 Series):

The ADA4861-3YRZ and ADA4861-3YRZ-RL7 maintain current feedback amplifier topology identical to the OPA3684IDRG4. These parts are active products manufactured by Analog Devices Inc. with ROHS3 compliance and REACH unaffected status. The ADA4861-3YRZ-RL7 variant offers superior inventory availability (18,300 units) and is packaged in Cut Tape & Digi-Reel format, suitable for high-volume production environments. Both ADA4861 variants provide extended operating temperature range (-40°C to 105°C) and improved moisture sensitivity rating (MSL 1, Unlimited).

General Purpose Topology Substitutes (ADA4862 Series):

The ADA4862-3YRZ, ADA4862-3YRZ-RL, and ADA4862-3YRZ-RL7 represent general purpose amplifier topology with enhanced performance characteristics. These parts deliver higher slew rate (1050 V/µs versus 780 V/µs) and -3dB bandwidth (720 MHz versus 250 MHz). All ADA4862 variants are active products with ROHS3 compliance, REACH unaffected status, and MSL 1 unlimited moisture sensitivity rating. The ADA4862-3YRZ-RL7 variant provides the highest inventory availability (15,733 units).

Supply Voltage Consideration:

All substitute parts require minimum supply voltage of 5 V, compared to the OPA3684IDRG4 minimum of 2.8 V. Applications operating below 5 V supply voltage cannot use these substitutes without circuit redesign.

Packaging and Availability:

All substitute parts maintain identical 14-SOIC package footprint and surface mount configuration. Selection between tube, cut tape & digi-reel, and tape & reel packaging depends on procurement and assembly requirements. Active product status ensures long-term availability and supply chain continuity.

Frequently Asked Questions (FAQ)

Q: Can the ADA4861-3YRZ directly replace the OPA3684IDRG4 in existing designs?

A: Direct replacement is possible if the application supply voltage is 5 V or higher. The ADA4861-3YRZ maintains current feedback topology and identical 14-SOIC package configuration. However, the lower slew rate (680 V/µs versus 780 V/µs) and reduced -3dB bandwidth (370 MHz versus 250 MHz) must be evaluated for specific circuit performance requirements. The extended operating temperature range (-40°C to 105°C) and improved input offset voltage (100 µV versus 1.5 mV) provide performance advantages in many applications.

Q: What is the difference between ADA4861 and ADA4862 substitute options?

A: The ADA4861-3YRZ series maintains current feedback amplifier topology matching the OPA3684IDRG4 architecture. The ADA4862-3YRZ series implements general purpose amplifier topology with significantly higher bandwidth (720 MHz versus 370 MHz) and slew rate (1050 V/µs versus 680 V/µs). Selection depends on whether the application requires current feedback characteristics or benefits from general purpose amplifier performance.

Q: Are packaging variants (tube, cut tape & digi-reel, tape & reel) electrically equivalent?

A: Yes. The ADA4861-3YRZ, ADA4861-3YRZ-RL7, ADA4862-3YRZ, ADA4862-3YRZ-RL, and ADA4862-3YRZ-RL7 are electrically identical. Packaging differences reflect only the delivery format: tube packaging for small quantities, cut tape & digi-reel for automated assembly, and tape & reel for high-volume production. Electrical specifications, performance characteristics, and compliance certifications are identical across all packaging variants of the same base part number.

Q: Why do substitute parts require 5 V minimum supply voltage while the OPA3684IDRG4 operates at 2.8 V minimum?

A: The substitute parts are specified with 5 V minimum supply voltage based on their design and characterization. Applications requiring operation below 5 V cannot use these substitutes without circuit redesign or alternative component selection.

Q: What is the significance of MSL rating differences?

A: The OPA3684IDRG4 carries MSL 2 rating (1 Year shelf life), while all substitute parts carry MSL 1 rating (Unlimited shelf life). MSL 1 provides superior moisture protection and extended storage capability, reducing risk of moisture-induced failures during extended inventory holding or in high-humidity environments.

Q: Are all substitute parts ROHS3 compliant?

A: Yes. The OPA3684IDRG4 and all identified substitute parts (ADA4861-3YRZ, ADA4861-3YRZ-RL7, ADA4862-3YRZ, ADA4862-3YRZ-RL, ADA4862-3YRZ-RL7) are ROHS3 compliant and REACH unaffected, meeting environmental and regulatory requirements for commercial and industrial applications.

Q: Which substitute part offers the best inventory availability?

A: The ADA4861-3YRZ-RL7 provides the highest inventory availability at 18,300 units, followed by ADA4862-3YRZ-RL7 at 15,733 units. Both are active products with unlimited moisture sensitivity rating and suitable for immediate procurement.