TOP233P Equivalent & Substitute Parts Reference

Part Overview

The TOP233P is an offline switch flyback converter IC manufactured by Power Integrations, designed for isolated power supply applications. This device operates in the TOPSwitch®-FX series and delivers 25W output power with integrated frequency control and comprehensive fault protection. The TOP233P is classified as obsolete, making identification of compatible substitute components essential for ongoing production support, design updates, and inventory management. Substitute parts must maintain electrical and mechanical compatibility while meeting current design and compliance requirements.

Substiute Parts

TOP233P

Power IntegrationsIn Stock: 1559TOP233P Datasheet

Current PartRFQ

TOP243PN

Power IntegrationsIn Stock: 1602TOP243PN Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute compatibility for the TOP233P is determined by strict adherence to the following electrical and mechanical parameters:

Critical Matching Parameters:

• Topology: Flyback converter architecture
• Output Isolation: Isolated configuration
• Voltage - Breakdown: 700V rating
• Power Output: 25W capability
• Switching Frequency Range: 66kHz ~ 132kHz
• Package / Case: 8-DIP (0.300", 7.62mm), 7 Leads
• Mounting Type: Through Hole
• Operating Temperature Range: -40°C ~ 150°C (TJ)
• Fault Protection: Current Limiting, Over Temperature, Over Voltage
• Control Features: Frequency Control
• Internal Switch(s): Integrated switch required

The TOP243PN qualifies as a parametric equivalent substitute based on matching all critical electrical specifications and mechanical package requirements. Both devices share identical topology, isolation characteristics, voltage ratings, power output, switching frequency range, package configuration, and thermal operating range. Differences in duty cycle (TOP233P: 78% vs TOP243PN: 66.5%) and product series designation (TOPSwitch®-FX vs TOPSwitch®-GX) do not preclude substitution when electrical and mechanical parameters align.

Parameter Comparison

Engineering Selection Recommendations

For Existing Designs Using TOP233P:

The TOP243PN serves as the direct parametric equivalent substitute. All critical electrical specifications—topology, isolation, voltage rating, power output, switching frequency, fault protection, and control features—are identical. Package configuration and mounting type are unchanged, enabling direct PCB-level substitution without layout modifications.

Compliance Considerations:

The TOP233P is RoHS non-compliant, while the TOP243PN is RoHS Compliant. Organizations subject to RoHS regulations or customer requirements mandating RoHS compliance must transition to the TOP243PN. Both devices carry identical REACH and ECCN classifications (REACH Unaffected, EAR99).

Product Status Impact:

Both the TOP233P (Obsolete) and TOP243PN (Not For New Designs) are legacy products. For new design initiatives, evaluation of current-generation TOPSwitch series components is recommended, though this determination falls outside the scope of equivalent part substitution.

Inventory and Availability:

TOP233P: 1487 Pcs New Original In Stock TOP243PN: 1510 Pcs New Original In Stock

Both components maintain adequate inventory levels for production support.

Frequently Asked Questions (FAQ)

Q: Can TOP243PN replace TOP233P in existing circuit designs?

A: Yes. The TOP243PN is a parametric equivalent substitute. All critical electrical parameters—topology, isolation, voltage rating, power output, switching frequency range, fault protection, and control features—match the TOP233P specification. Package configuration (8-DIP, 7 Leads, Through Hole) is identical, enabling direct substitution without PCB redesign.

Q: What is the significance of the duty cycle difference between TOP233P (78%) and TOP243PN (66.5%)?

A: Duty cycle is a design parameter that reflects the internal control architecture of each device. Both devices operate within the same switching frequency range (66kHz ~ 132kHz) and deliver identical 25W output power. The duty cycle difference does not prevent substitution when all other electrical and mechanical parameters align.

Q: Does the series change from TOPSwitch®-FX to TOPSwitch®-GX affect substitution compatibility?

A: No. Series designation indicates product family evolution within Power Integrations' portfolio. Substitution compatibility is determined by matching electrical specifications and mechanical package requirements, both of which are identical between TOP233P and TOP243PN.

Q: Why is TOP243PN marked "Not For New Designs" if it is a suitable substitute?

A: Product status reflects manufacturer recommendations for new design initiatives. The "Not For New Designs" designation does not preclude use as a substitute for obsolete components in existing production or design updates. For new designs, current-generation components should be evaluated.

Q: What is the impact of RoHS compliance differences?

A: TOP233P is RoHS non-compliant; TOP243PN is RoHS Compliant. Organizations operating under RoHS regulations (EU Directive 2011/65/EU) or serving customers with RoHS requirements must use TOP243PN. RoHS compliance status does not affect electrical or mechanical substitution capability.

Q: Are there any thermal or operating temperature considerations for substitution?

A: Both devices operate across the identical temperature range: -40°C ~ 150°C (TJ). No thermal derating adjustments are required when substituting TOP243PN for TOP233P.

Q: Can multiple substitute parts be used interchangeably in the same production run?

A: Yes. TOP243PN is the qualified parametric equivalent. Both devices share identical electrical specifications and package configuration. Interchangeable use in production is supported by matching specifications.

Q: What documentation should be reviewed before implementing substitution?

A: Consult the TOP233P and TOP243PN datasheets to confirm pin configuration, control pin functionality, and application circuit requirements. While electrical and mechanical parameters are equivalent, application-specific circuit design details should be verified against current device documentation.