RT9218CPS Equivalent & Substitute Parts

Part Overview

The RT9218CPS is a dual-output PMIC from Richtek USA Inc. integrating one synchronous step-down (buck) regulator and one linear (LDO) regulator in a 14-SOIC package. This device operates across a 5V to 12V supply range with a 300kHz switching frequency and is designed for applications requiring mixed regulation topologies. The RT9218CPS is classified as obsolete, necessitating identification of functionally equivalent alternatives for new designs and ongoing production support.

Substiute Parts

RT9218CPS

Richtek USA Inc.In Stock: 753RT9218CPS Datasheet

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RT8120FGS

Richtek USA Inc.In Stock: 725RT8120FGS Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution of the RT9218CPS requires matching the following critical parameters:

• Topology: The RT9218CPS combines synchronous buck and linear regulation in a single package. Direct substitutes must provide equivalent output configurations.
• Number of Outputs: Dual-output capability (one buck, one LDO) is a defining characteristic.
• Switching Frequency: 300kHz operation determines timing and filtering requirements.
• Supply Voltage Range: 5V to 12V input compatibility is essential for system integration.
• Operating Temperature Range: -40°C to 85°C defines environmental suitability.
• Package Compatibility: 14-SOIC form factor constrains PCB layout and thermal management.
• Compliance Standards: ROHS3 compliance and MSL rating ensure manufacturing and reliability requirements.

The RT8120FGS is a single-output buck controller that does not provide the dual-output (buck + LDO) configuration of the RT9218CPS. This part represents a functional alternative only for applications requiring the buck regulation stage, with external components required to replicate the LDO function.

Parameter Comparison

Engineering Selection Recommendations

The RT8120FGS is an active product from the same manufacturer with matching switching frequency, operating temperature range, and compliance certifications. However, this substitute provides only single-output buck regulation, whereas the RT9218CPS integrates both buck and LDO outputs. Selection of the RT8120FGS requires external linear regulation circuitry to replicate the LDO function of the original device.

The RT8120FGS operates across a wider supply voltage range (3V to 13.2V) compared to the RT9218CPS (5V to 12V), providing additional flexibility for input voltage variations. Both devices maintain ROHS3 compliance and identical MSL ratings, ensuring equivalent manufacturing and storage requirements.

Frequently Asked Questions (FAQ)

Q: Can the RT8120FGS directly replace the RT9218CPS?

A: No. The RT8120FGS is a single-output buck controller, while the RT9218CPS integrates both buck and LDO regulation. Direct replacement requires external linear regulation components to provide the LDO output function.

Q: What are the key differences in package size?

A: The RT9218CPS uses a 14-SOIC package, while the RT8120FGS uses an 8-SOIC package. Both maintain the same 0.154" (3.90mm) width, but the pin count and footprint differ, requiring PCB redesign.

Q: Are both devices suitable for -40°C to 85°C operation?

A: Yes. Both the RT9218CPS and RT8120FGS support the full -40°C to 85°C operating temperature range.

Q: Do both devices meet RoHS compliance requirements?

A: Yes. Both devices are ROHS3 compliant with identical MSL ratings of 3 (168 Hours).

Q: What is the significance of the RT9218CPS being obsolete?

A: Obsolete status indicates the device is no longer manufactured. The RT8120FGS, classified as active, remains in production and available for new designs requiring buck regulation functionality.

Q: How does the supply voltage range differ between these devices?

A: The RT9218CPS operates from 5V to 12V, while the RT8120FGS operates from 3V to 13.2V. The wider range of the RT8120FGS accommodates additional input voltage scenarios.