UC2573N Buck Regulator Controller - Equivalent & Substitute Parts

Part Overview

The UC2573N is a buck regulator positive output step-down DC-DC controller IC manufactured by Texas Instruments in 8-PDIP packaging. This device functions as a transistor driver for step-down topology applications with a single output phase. The UC2573N is classified as obsolete, making identification of equivalent and substitute parts essential for ongoing design support and procurement continuity. Active alternatives are available that maintain core functional compatibility while offering improved availability and extended product lifecycle status.

Substiute Parts

UC2573N

Texas InstrumentsIn Stock: 759UC2573N Datasheet

Current PartRFQ

MAX1649CPA+

Analog Devices Inc./Maxim IntegratedIn Stock: 1189MAX1649CPA+ Datasheet

MFR RecommendedRFQ

UC2573D

Texas InstrumentsIn Stock: 1402UC2573D Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the UC2573N are identified based on functional equivalence within the allowed electrical and mechanical parameters for buck regulator controller ICs. The primary substitution criteria are:

Core Functional Parameters:

• Output type: Transistor driver
• Function: Step-down DC-DC control
• Output configuration: Positive
• Topology: Buck
• Number of outputs: 1
• Package form factor: 8-DIP pinout compatibility
• Mounting technology compatibility

Electrical Operating Range: Substitutes must support the required supply voltage range and switching frequency specifications. The UC2573N operates at 4.75V ~ 30V with 100kHz switching frequency and 92% maximum duty cycle.

Environmental & Compliance: All substitutes maintain ROHS3 compliance, MSL Level 1 rating, and REACH unaffected status, ensuring regulatory continuity.

Two substitute parts meet these criteria: the MAX1649CPA+ (Analog Devices Inc./Maxim Integrated) and the UC2573D (Texas Instruments). The MAX1649CPA+ provides functional equivalence in 8-DIP through-hole packaging with active product status. The UC2573D maintains identical electrical specifications and control features from the original manufacturer but uses 8-SOIC surface-mount packaging, requiring PCB redesign for implementation.

Parameter Comparison

Engineering Selection Recommendations

For Direct Through-Hole Replacement (No PCB Redesign):

The MAX1649CPA+ is the appropriate selection when PCB layout cannot be modified. This part maintains the 8-DIP through-hole form factor and is currently in active production status with 1162 units in stock. The MAX1649CPA+ is ROHS3 compliant and carries MSL Level 1 rating. Note that the supply voltage range is narrower (3V ~ 16V versus 4.75V ~ 30V), requiring verification that your application operates within this reduced range. The operating temperature range is also reduced (0°C ~ 70°C versus -40°C ~ 85°C), which may impact suitability for extended temperature applications.

For Equivalent Electrical Performance with Surface-Mount Implementation:

The UC2573D provides identical electrical specifications and control features to the UC2573N while maintaining Texas Instruments as the manufacturer. This part is in active production with 1374 units in stock. The UC2573D requires PCB redesign due to 8-SOIC surface-mount packaging but offers full compatibility with the original supply voltage range (4.75V ~ 30V), switching frequency (100kHz), duty cycle (92%), and operating temperature range (-40°C ~ 85°C). ROHS3 compliance and MSL Level 1 rating are maintained.

Compliance & Availability:

Both substitute parts maintain ROHS3 compliance, REACH unaffected status, and MSL Level 1 moisture sensitivity ratings. Both are currently in active production with adequate inventory levels.

Frequently Asked Questions (FAQ)

Q: Can the MAX1649CPA+ be used as a direct replacement for the UC2573N without PCB modifications?

A: Yes, the MAX1649CPA+ uses identical 8-DIP through-hole packaging (0.300", 7.62mm) and can be installed in existing PCB footprints. However, the reduced supply voltage range (3V ~ 16V) and operating temperature range (0°C ~ 70°C) must be verified against your application requirements before implementation.

Q: What is the primary difference between the MAX1649CPA+ and UC2573D substitutes?

A: The MAX1649CPA+ maintains through-hole 8-DIP packaging for direct PCB replacement but has reduced electrical operating ranges. The UC2573D uses surface-mount 8-SOIC packaging and requires PCB redesign but provides identical electrical specifications and full operating ranges to the original UC2573N.

Q: Does the UC2573D maintain the same control features as the UC2573N?

A: Yes, the UC2573D includes identical control features (Current Limit, Ramp) and maintains the same supply voltage range (4.75V ~ 30V), switching frequency (100kHz), and maximum duty cycle (92%) as the UC2573N.

Q: Are both substitute parts RoHS compliant?

A: Yes, both the MAX1649CPA+ and UC2573D are ROHS3 compliant with MSL Level 1 moisture sensitivity ratings and REACH unaffected status.

Q: Which substitute should I select if my application requires the full -40°C ~ 85°C operating temperature range?

A: The UC2573D is the appropriate selection, as it maintains the full -40°C ~ 85°C operating temperature range. The MAX1649CPA+ is limited to 0°C ~ 70°C.

Q: What inventory levels are available for each substitute?

A: The MAX1649CPA+ has 1162 units in stock, and the UC2573D has 1374 units in stock, both in new original condition.