PT78ST115ST Equivalent & Substitute Parts Reference

Part Overview

The PT78ST115ST, manufactured by Texas Instruments, is a non-isolated Point-of-Load (PoL) DC DC converter module designed for commercial ITE applications. It features a single output of 15V at a maximum current of 1.5A, supports input voltages from 19V to 38V, and incorporates protection features such as over-temperature protection (OTP) and short-circuit protection (SCP). The part is obsolete, making it necessary to identify and qualify alternative components for use in existing and new designs requiring similar form, fit, and function.

Substiute Parts

PT78ST115ST

Texas InstrumentsIn Stock: 1217PT78ST115ST Datasheet

Current PartRFQ

TPS84250RKGT

Texas InstrumentsIn Stock: 1480TPS84250RKGT Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute selection for the PT78ST115ST is governed strictly by match or overlap of key electrical and mechanical parameters within the DC DC converter category. Valid substitutes must provide non-isolated PoL operation, support commercial ITE applications, match or exceed the required output voltage and current, and operate within the same or broader input voltage range. Package type, mounting method, and regulatory compliance are also considered. Only parts explicitly listed as substitutes for this part number and sharing these essential characteristics are included.

Key parameters used for substitute grouping:

• Output Voltage and Current
• Input Voltage Range
• Module Type (Non-Isolated PoL)
• Number of Outputs
• Operating Temperature
• Efficiency
• Mounting Type
• Package / Case
• RoHS Compliance
• Product Status

Parameter Comparison

Engineering Selection Recommendations

The PT78ST115ST is obsolete; continued use is not supported for new designs. Substitution is permitted only with parts confirmed to meet all required electrical, mechanical, and regulatory criteria as listed. The TPS84250RKGT meets RoHS3 compliance and is active in inventory, making it suitable as an equivalent substitute in contexts requiring regulatory adherence.

Frequently Asked Questions (FAQ)

Q1: Which parameters are critical when substituting the PT78ST115ST DC DC converter?
A1: Critical substitution parameters include output voltage and current, input voltage range, module type, number of outputs, mounting type, package/case, operating temperature, and regulatory compliance.

Q2: Does the TPS84250RKGT cover the same output voltage and current requirements?
A2: TPS84250RKGT supports a voltage output range from 2.5V to 15V at up to 2.5A, encompassing the required 15V and exceeding the required current specification.

Q3: How do physical dimensions and package format differ between alternatives?
A3: The PT78ST115ST uses a 3-SMD Module (0.94" x 0.90" x 0.34"), while the TPS84250RKGT uses a 41-BQFN Module (0.43" x 0.35" x 0.11"). Design review is necessary to confirm mechanical fit based solely on supplied parameters.

Q4: Is RoHS compliance maintained with listed substitutes?
A4: Both PT78ST115ST and TPS84250RKGT are ROHS3 compliant per provided parameters.

Q5: Are protection and control features comparable between the PT78ST115ST and TPS84250RKGT?
A5: PT78ST115ST provides OTP and SCP; TPS84250RKGT adds OCP, OTP, and UVLO protection features.

Q6: What are the relevant product statuses for selection?
A6: PT78ST115ST is obsolete, while TPS84250RKGT is active; ongoing supply considerations favor the substitute part.