OPA637AP Equivalent & Substitute Parts Reference

Part Overview

The OPA637AP is a general-purpose operational amplifier manufactured by Texas Instruments, housed in an 8-PDIP through-hole package. This device is classified as obsolete, though 1,355 units remain available in new original stock. The OPA637AP operates within the Difet® series and is designed for applications requiring moderate gain-bandwidth performance and low input bias current characteristics.

Due to its obsolete status, identifying equivalent and substitute parts is essential for design continuity, long-term supply chain planning, and new product development. Substitute parts must maintain functional compatibility across critical electrical parameters including slew rate, gain-bandwidth product, input bias current, and supply voltage specifications.

Substiute Parts

OPA637AP

Texas InstrumentsIn Stock: 1462OPA637AP Datasheet

Current PartRFQ

OPA828IDR

Texas InstrumentsIn Stock: 16747OPA828IDR Datasheet

MFR RecommendedRFQ

AD744KNZ

Analog Devices Inc.In Stock: 1614AD744KNZ Datasheet

MFR RecommendedRFQ

OP90GPZ

Analog Devices Inc.In Stock: 1446OP90GPZ Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution logic for the OPA637AP is based on the following critical parameters that determine functional compatibility:

Primary Substitution Criteria:

• Amplifier Type (General Purpose or J-FET)
• Number of Circuits (must equal 1)
• Slew Rate (minimum 135 V/µs preferred for performance equivalence)
• Gain Bandwidth Product (minimum 80 MHz preferred)
• Input Bias Current (2 pA or lower)
• Supply Voltage Range (minimum 9 V, maximum 36 V)
• Package compatibility (8-DIP through-hole or surface-mount alternatives)

Substitute Parts Identified:

1. OPA828IDR (Texas Instruments) — J-FET amplifier with higher slew rate (150 V/µs), lower input bias current (1 pA), active product status. Surface-mount 8-SOIC package represents a packaging change from through-hole.

2. AD744KNZ (Analog Devices Inc.) — J-FET amplifier in 8-PDIP through-hole package, maintains package compatibility. Lower slew rate (75 V/µs) and reduced gain-bandwidth product (13 MHz) represent performance trade-offs. Active product status.

3. OP90GPZ (Analog Devices Inc.) — General-purpose amplifier in 8-PDIP through-hole package, maintains package and amplifier type compatibility. Significantly lower slew rate (0.012 V/µs) and reduced output current (5 mA) represent substantial performance reduction. Active product status with extended operating temperature range.

Parameter Comparison

Engineering Selection Recommendations

OPA828IDR Selection Criteria: The OPA828IDR is an active product from Texas Instruments with superior electrical performance characteristics: higher slew rate (150 V/µs vs. 135 V/µs), lower input bias current (1 pA vs. 2 pA), and improved input offset voltage (50 µV vs. 130 µV). Extended operating temperature range (-40°C ~ 125°C) provides broader environmental coverage. Primary trade-off is packaging: surface-mount 8-SOIC requires PCB redesign from through-hole 8-DIP. ROHS3 compliance and REACH unaffected status maintain regulatory alignment. Recommended for new designs prioritizing performance and long-term supply availability.

AD744KNZ Selection Criteria: The AD744KNZ maintains through-hole 8-DIP package compatibility, eliminating PCB redesign requirements. Active product status from Analog Devices ensures supply continuity. Trade-offs include reduced slew rate (75 V/µs), significantly lower gain-bandwidth product (13 MHz), and higher input bias current (30 pA). Operating temperature range (0°C ~ 70°C) is narrower than OPA637AP. ROHS3 compliance maintained. Recommended for applications where package compatibility is critical and performance reduction is acceptable.

OP90GPZ Selection Criteria: The OP90GPZ maintains through-hole 8-DIP package and general-purpose amplifier type. Extended operating temperature range (-40°C ~ 85°C) exceeds OPA637AP specifications. Significant performance reduction across multiple parameters: slew rate (0.012 V/µs), output current (5 mA), and gain-bandwidth product not specified. Supply current reduced to 14 µA. ROHS3 compliance maintained. Recommended only for low-speed, low-power applications where performance trade-offs are acceptable.

Compliance Summary: All substitute parts maintain ROHS3 compliance and REACH unaffected status, ensuring regulatory continuity. All parts are classified under HTSUS 8542.33.0001 and ECCN EAR99.

Frequently Asked Questions (FAQ)

Q1: Can OPA828IDR directly replace OPA637AP without PCB modifications?

The OPA828IDR uses 8-SOIC surface-mount packaging versus OPA637AP's 8-DIP through-hole package. Direct socket replacement is not possible. PCB redesign is required to accommodate the different package footprint and pin spacing (3.90mm vs. 7.62mm width).

Q2: Which substitute part offers the closest electrical performance to OPA637AP?

The OPA828IDR provides the closest performance match with higher slew rate (150 V/µs vs. 135 V/µs), lower input bias current (1 pA vs. 2 pA), and improved input offset voltage (50 µV vs. 130 µV). However, gain-bandwidth product is reduced (45 MHz vs. 80 MHz).

Q3: Is AD744KNZ suitable for high-speed signal processing applications?

No. The AD744KNZ has significantly reduced slew rate (75 V/µs) and gain-bandwidth product (13 MHz) compared to OPA637AP (135 V/µs and 80 MHz). It is suitable for lower-speed applications only.

Q4: What is the primary advantage of OP90GPZ?

The OP90GPZ offers extremely low supply current (14 µA) and operates from lower supply voltages (1.6 V minimum). It is optimized for battery-powered and ultra-low-power applications. Performance is significantly reduced across slew rate and output current specifications.

Q5: Are all substitute parts RoHS compliant?

Yes. OPA828IDR, AD744KNZ, and OP90GPZ are all ROHS3 compliant and REACH unaffected, maintaining regulatory alignment with OPA637AP.

Q6: Which substitute part has the widest operating temperature range?

The OPA828IDR operates across -40°C ~ 125°C, providing the widest temperature coverage. OPA637AP operates -25°C ~ 85°C, AD744KNZ operates 0°C ~ 70°C, and OP90GPZ operates -40°C ~ 85°C.

Q7: Can substitute parts be used interchangeably in existing OPA637AP designs?

No. Each substitute part has different electrical characteristics and packaging. Circuit redesign and validation are required for any substitution. Package compatibility must be verified before implementation.

Q8: What is the inventory status of substitute parts?

OPA828IDR: 16,718 units in stock. AD744KNZ: 1,529 units in stock. OP90GPZ: 1,363 units in stock. All substitute parts have active product status, ensuring long-term availability compared to OPA637AP's obsolete status.