RT9172-33GG Equivalent & Substitute Parts

Part Overview

The RT9172-33GG is a linear voltage regulator IC from Richtek USA Inc. designed for positive fixed 3.3V output applications with 3A current capacity in a compact SOT-223 package. This part is classified as obsolete, making identification of suitable substitute components essential for ongoing design support and production continuity. The fixed output configuration and dropout characteristics define the substitution parameters for this power management IC.

Substiute Parts

RT9172-33GG

Richtek USA Inc.In Stock: 2116RT9172-33GG Datasheet

Current PartRFQ

RT9059AGQW

Richtek USA Inc.In Stock: 1691RT9059AGQW Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

The RT9059AGQW qualifies as a functional substitute based on the following alignment of critical electrical parameters:

Matching Parameters:

• Output current capacity: 3A (identical)
• Input voltage maximum: 5.5V (identical)
• Dropout voltage: 0.45V @ 3A (superior performance)
• Output configuration: Positive (identical)
• Protection features: Over Current, Over Temperature (both present, plus additional protections in substitute)
• RoHS3 compliance: Both compliant
• Mounting type: Surface Mount (identical)

Key Difference: The RT9059AGQW features adjustable output voltage (0.8V to 5.5V range) versus the fixed 3.3V output of the RT9172-33GG. When configured for 3.3V output through external resistor network, this substitute provides equivalent functionality with improved electrical characteristics.

Parameter Comparison

Engineering Selection Recommendations

The RT9059AGQW is an active product with current manufacturing support, addressing the obsolescence status of the RT9172-33GG. Both components maintain ROHS3 compliance and identical maximum input voltage specifications. The substitute offers superior electrical performance through reduced dropout voltage (0.45V versus 0.7V) and lower quiescent current (1.2 mA versus 3 mA), resulting in improved power efficiency.

The primary design consideration involves package transition from SOT-223 to 10-WDFN (3x3) and output voltage configuration from fixed to adjustable. The adjustable output requires external resistor network design to establish 3.3V output, adding circuit complexity but enabling voltage flexibility for future applications.

The operating temperature range of the substitute extends to 85°C maximum versus 125°C for the original part. Applications requiring operation above 85°C require alternative component evaluation.

Frequently Asked Questions (FAQ)

Q: Can the RT9059AGQW directly replace the RT9172-33GG without circuit modifications?

A: Direct pin-for-pin replacement is not possible due to package differences (SOT-223 versus 10-WDFN) and output voltage configuration. The RT9059AGQW requires external resistor network design to set 3.3V output and PCB layout redesign for the larger WDFN package.

Q: What are the electrical advantages of substituting to the RT9059AGQW?

A: The substitute provides 0.25V lower dropout voltage and 1.8 mA lower quiescent current, reducing power dissipation and improving voltage regulation performance under load conditions. Additional protection features include short circuit protection and under voltage lockout.

Q: Is the RT9059AGQW suitable for applications requiring operation above 85°C?

A: No. The RT9059AGQW maximum operating temperature is 85°C, compared to 125°C for the RT9172-33GG. Applications with higher temperature requirements must evaluate alternative components.

Q: What is the impact of changing from fixed to adjustable output voltage?

A: The adjustable output requires external resistor divider network design to establish 3.3V output. This adds component count and design complexity but enables voltage adjustment capability for future product variants without component substitution.

Q: Are both components RoHS compliant?

A: Yes. Both the RT9172-33GG and RT9059AGQW are ROHS3 compliant and REACH unaffected, meeting environmental regulatory requirements.