CS51221EDR16 Equivalent & Substitute Parts

Part Overview

The CS51221EDR16 is a Forward Converter Regulator controller IC manufactured by onsemi, designed for positive, isolation-capable output step-up/step-down DC-DC conversion applications. This 16-SOIC surface mount device operates as a transistor driver with integrated current limit, frequency control, ramp, and soft start control features.

The CS51221EDR16 is classified as obsolete. Identifying equivalent substitute parts is necessary to ensure design continuity, maintain supply chain reliability, and support long-term product availability for applications currently utilizing this controller.

Substiute Parts

CS51221EDR16

onsemiIn Stock: 1085CS51221EDR16 Datasheet

Current PartRFQ

CS51221EDR16G

onsemiIn Stock: 3326CS51221EDR16G Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the CS51221EDR16 are identified based on strict electrical and mechanical parameter matching. The primary substitution criteria are:

• Identical topology (Forward Converter)
• Matching output type (Transistor Driver)
• Identical function (Step-Up/Step-Down)
• Matching output configuration (Positive, Isolation Capable)
• Identical package (16-SOIC)
• Matching voltage supply range (3.8V ~ 15V)
• Matching switching frequency (1MHz)
• Matching maximum duty cycle (85%)
• Identical control features (Current Limit, Frequency Control, Ramp, Soft Start)
• Compatible operating temperature range (-40°C ~ 85°C)

The CS51221EDR16G meets all these criteria and is classified as a direct manufacturer equivalent substitute.

Parameter Comparison

Engineering Selection Recommendations

The CS51221EDR16G is a direct functional equivalent to the CS51221EDR16. Both devices share identical electrical specifications, control features, and package geometry, ensuring pin-for-pin and functional compatibility in forward converter applications.

The primary distinction between these parts is regulatory compliance. The CS51221EDR16G carries ROHS3 compliance certification, whereas the CS51221EDR16 is RoHS non-compliant. For applications subject to RoHS regulations or requiring compliance documentation, the CS51221EDR16G is the appropriate selection. Both parts are classified as obsolete, indicating limited future availability through standard distribution channels.

Frequently Asked Questions (FAQ)

Q: Can CS51221EDR16G be used as a direct replacement for CS51221EDR16?

A: Yes. Both devices are identical in electrical performance, control features, switching characteristics, and 16-SOIC package configuration. Pin-for-pin substitution is supported without circuit modification.

Q: What is the primary difference between CS51221EDR16 and CS51221EDR16G?

A: The CS51221EDR16G is ROHS3 compliant, while the CS51221EDR16 is RoHS non-compliant. All electrical and functional parameters are identical.

Q: Are there any package or mounting differences between these parts?

A: No. Both parts use the 16-SOIC (0.154", 3.90mm Width) surface mount package with identical pinout and mechanical dimensions.

Q: What supply voltage range do these controllers support?

A: Both the CS51221EDR16 and CS51221EDR16G operate with a supply voltage range of 3.8V to 15V.

Q: What is the switching frequency specification for these devices?

A: Both devices operate at a fixed switching frequency of 1MHz with a maximum duty cycle of 85%.

Q: Are these parts still in production?

A: No. Both the CS51221EDR16 and CS51221EDR16G are classified as obsolete. Existing inventory may be available through authorized distributors, but future production is not planned.