RT9193-28GF Linear Voltage Regulator

Part Overview

The RT9193-28GF is an active linear voltage regulator IC manufactured by Richtek USA Inc., designed for positive fixed output applications. This device delivers a fixed 2.8V output at 300mA with a maximum dropout voltage of 0.3V at full load current. The regulator integrates over-current and over-temperature protection features, making it suitable for low-power supply applications requiring stable voltage regulation across industrial and commercial temperature ranges (-40°C to 125°C). As an active product with ROHS3 compliance and established supply availability, alternative components may be required due to design optimization, supply chain considerations, or specific application requirements.

Substiute Parts

RT9193-28GF

Richtek USA Inc.In Stock: 798RT9193-28GF Datasheet

Current PartRFQ

LP3981IMM-2.8/NOPB

Texas InstrumentsIn Stock: 44197LP3981IMM-2.8/NOPB Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the RT9193-28GF is determined by strict equivalence across the following critical parameters:

Fixed Output Voltage: Both the main part and substitute must deliver 2.8V fixed output to ensure direct replacement without circuit modification.

Output Current Rating: The substitute must support 300mA continuous output current to maintain equivalent load-driving capability.

Input Voltage Compatibility: Maximum input voltage specifications must be compatible with the application's supply rail. The RT9193-28GF accepts up to 5.5V; substitutes must support this range or higher.

Dropout Voltage Performance: The substitute's dropout voltage directly affects minimum input voltage requirements and thermal performance. Lower dropout voltage indicates superior efficiency.

Package and Pinout: Both devices use 8-MSOP surface-mount packaging with identical pin configurations, enabling direct PCB-level substitution without layout redesign.

Operating Temperature Range: Both parts support -40°C to 125°C operation, ensuring functional equivalence across industrial temperature specifications.

Protection and Control Features: Equivalent protection (over-current, over-temperature) and enable control functionality must be present to maintain system reliability.

Regulatory Compliance: Both parts maintain ROHS3 compliance and equivalent environmental certifications for supply chain and regulatory consistency.

Parameter Comparison

Engineering Selection Recommendations

Both the RT9193-28GF and LP3981IMM-2.8/NOPB are active products with ROHS3 compliance and equivalent regulatory status (REACH Unaffected, EAR99 classification). Selection between these devices is based on application-specific requirements:

RT9193-28GF Selection Criteria: Choose this device when the application requires the Richtek supply chain, existing inventory commitments, or when the 8-MSOP package footprint is already established in production designs. The 0.3V dropout voltage is acceptable for applications with adequate input voltage margin above 3.1V.

LP3981IMM-2.8/NOPB Selection Criteria: This Texas Instruments substitute offers superior performance characteristics: 0.2V dropout voltage (100mV lower), lower quiescent current (120µA vs. 130µA), higher maximum input voltage (6V vs. 5.5V), and additional short-circuit protection. The MSL rating of 1 (Unlimited) provides superior moisture handling compared to MSL 3. The 8-VSSOP package is mechanically compatible with 8-MSOP footprints. This device is preferred for new designs, applications requiring maximum efficiency, or when higher input voltage tolerance is beneficial.

Both devices maintain identical output voltage, current rating, operating temperature range, and core protection features, ensuring functional equivalence in the application circuit.

Frequently Asked Questions (FAQ)

Q: Can the LP3981IMM-2.8/NOPB directly replace the RT9193-28GF on an existing PCB?

A: Yes. Both devices use 8-pin surface-mount packages (8-MSOP and 8-VSSOP) with identical pinout configurations. The LP3981IMM-2.8/NOPB can be soldered directly into the RT9193-28GF footprint without PCB modification. Verify that the PCB layout accommodates the slightly different package dimensions (both are 0.118" width, 3.00mm standard).

Q: What is the functional difference between these two regulators?

A: Both deliver identical 2.8V fixed output at 300mA with equivalent protection and control features. The LP3981IMM-2.8/NOPB provides lower dropout voltage (0.2V vs. 0.3V), marginally lower quiescent current, higher input voltage rating (6V vs. 5.5V), and additional short-circuit protection. These differences improve efficiency and system margin but do not affect basic functional equivalence.

Q: Are there any compliance or certification differences?

A: Both parts are ROHS3 compliant, REACH Unaffected, and classified as EAR99. The primary difference is MSL rating: RT9193-28GF is MSL 3 (168-hour moisture sensitivity limit), while LP3981IMM-2.8/NOPB is MSL 1 (unlimited). For applications with extended storage or high-humidity environments, the LP3981IMM-2.8/NOPB offers superior moisture tolerance.

Q: Which device should be specified for a new design?

A: The LP3981IMM-2.8/NOPB is recommended for new designs due to superior electrical performance (lower dropout voltage, lower quiescent current), higher input voltage rating, additional short-circuit protection, and better moisture handling (MSL 1). These characteristics provide design margin and long-term supply reliability.

Q: What is the impact of the 0.1V dropout voltage difference?

A: The LP3981IMM-2.8/NOPB's 0.2V dropout voltage requires minimum input voltage of 3.0V for full 300mA output. The RT9193-28GF requires 3.1V minimum. In applications with marginal input voltage, the lower dropout voltage of the LP3981IMM-2.8/NOPB provides additional operating margin and reduced thermal dissipation.

Q: Are package dimensions identical?

A: Both use 8-pin surface-mount packages with 0.118" (3.00mm) width. The RT9193-28GF uses 8-MSOP; the LP3981IMM-2.8/NOPB uses 8-VSSOP. These packages are mechanically compatible and interchangeable on standard PCB footprints designed for 8-pin 3.00mm-width packages.