PT4142C Isolated DC-DC Converter 5V 20W - Equivalent & Substitute Parts

Part Overview

The PT4142C is an isolated module DC-DC converter manufactured by Texas Instruments, designed to convert input voltages between 18V and 40V to a regulated 5V output at 4A maximum current. This 20W converter features remote on/off control, over-temperature protection (OTP), short-circuit protection (SCP), and under-voltage lockout (UVLO) functionality, making it suitable for commercial ITE (Information Technology Equipment) applications.

The PT4142C is classified as an obsolete product. Identifying equivalent and substitute parts is necessary to maintain system continuity, ensure design flexibility, and support long-term product availability for applications currently utilizing this converter.

Substiute Parts

PT4142C

Texas InstrumentsIn Stock: 710PT4142C Datasheet

Current PartRFQ

RP20-4805SFW

Recom PowerIn Stock: 1097RP20-4805SFW Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the PT4142C is determined by strict alignment of the following critical electrical and mechanical parameters:

Electrical Compatibility Criteria:

• Output voltage must be 5V
• Output current capability must be minimum 4A
• Input voltage range must encompass or exceed the 18V - 40V specification
• Isolation voltage must meet or exceed 1.5 kV
• Power rating must be 20W or greater
• Operating temperature range must support -40°C to 85°C operation

Mechanical Compatibility Criteria:

• Mounting type and package footprint must be compatible with the application PCB
• Physical dimensions must fit within the allocated board space
• Pin configuration must support the required control functions

Compliance Criteria:

• RoHS3 compliance required
• MSL rating of 1 (Unlimited) preferred for handling flexibility

The RP20-4805SFW from Recom Power qualifies as a substitute based on matching the core electrical output specifications (5V, 4A, 20W) and exceeding the input voltage range capability. However, differences in mounting type, package configuration, and operating temperature maximum must be evaluated for specific application requirements.

Parameter Comparison

Engineering Selection Recommendations

For Direct Electrical Substitution:

The RP20-4805SFW meets the core electrical output requirements of the PT4142C (5V, 4A, 20W output) and provides enhanced input voltage range capability (18V - 75V versus 18V - 40V). Both parts maintain ROHS3 compliance and MSL-1 moisture sensitivity ratings, supporting equivalent handling and storage protocols.

Critical Design Considerations:

1. Mounting Technology Transition: The PT4142C uses surface-mount (SMD) technology, while the RP20-4805SFW uses through-hole (DIP) technology. This difference requires PCB redesign and cannot be accommodated through simple footprint adaptation.

2. Operating Temperature Envelope: The RP20-4805SFW specifies a maximum operating temperature of 63°C, compared to the PT4142C maximum of 85°C. Applications requiring sustained operation above 63°C are not suitable for this substitute without thermal management verification.

3. Physical Form Factor: The RP20-4805SFW has larger overall dimensions (50.8mm length versus 43.9mm) and different aspect ratio. Verify available board space before selection.

4. Compliance Status: Both parts maintain equivalent regulatory compliance (ROHS3, REACH Unaffected, EAR99 ECCN classification, identical HTSUS code 8504.40.9580).

Substitution Feasibility:

The RP20-4805SFW is electrically suitable as a substitute where PCB redesign is acceptable and the operating temperature maximum of 63°C is compatible with the application thermal environment. Direct pin-for-pin replacement is not possible due to package technology differences.

Frequently Asked Questions (FAQ)

Q: Can the RP20-4805SFW replace the PT4142C without PCB modification?

A: No. The PT4142C uses surface-mount (SMD) packaging while the RP20-4805SFW uses through-hole (DIP) packaging. These require different PCB footprints and cannot be interchanged without circuit board redesign.

Q: What are the key electrical parameters that make the RP20-4805SFW compatible?

A: Both converters provide identical output specifications (5V, 4A, 20W), matching input voltage minimum (18V), and equivalent isolation voltage performance (1.5 kV versus 1.6 kV). These parameters define functional compatibility for the power conversion requirement.

Q: Does the RP20-4805SFW's higher input voltage maximum (75V) create any issues?

A: No. The higher maximum input rating (75V versus 40V) provides additional design margin and does not create compatibility issues. The converter will operate correctly across the PT4142C's specified 18V - 40V input range.

Q: Why is the RP20-4805SFW's maximum operating temperature lower (63°C versus 85°C)?

A: This reflects different thermal design specifications between manufacturers. Applications operating in environments where ambient temperature plus component self-heating exceeds 63°C require thermal analysis to confirm the substitute is suitable. The PT4142C's higher rating provides greater thermal headroom for high-power or high-ambient applications.

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

A: No. Both parts maintain identical compliance status: ROHS3 compliant, REACH unaffected, MSL-1 moisture sensitivity, and EAR99 ECCN classification. Regulatory requirements do not differentiate between these converters.

Q: What is the efficiency difference, and does it matter?

A: The RP20-4805SFW provides 86% efficiency versus the PT4142C's 82%. This 4-percentage-point improvement reduces power dissipation and heat generation, which may benefit thermal management in space-constrained applications.

Q: How do the physical dimensions affect substitution?

A: The RP20-4805SFW is larger (50.8 × 25.4 × 10.2 mm versus 43.9 × 38.6 × 8.5 mm). Verify that available board space accommodates the substitute's footprint and height before committing to redesign.

Q: What control features differ between these converters?

A: The PT4142C features remote on/off control, while the RP20-4805SFW provides enable control with active-high logic. Both include OCP, OVP, SCP, and UVLO protection. Verify that the enable control interface is compatible with your system's power management architecture.