MAX121C/D Equivalent & Substitute Parts

Part Overview

The MAX121C/D is a 14-bit Analog to Digital Converter (ADC) with single-ended input, SAR architecture, and SPI data interface. This component is designed for data acquisition applications requiring moderate sampling rates of 308 kSPS. The part is currently obsolete, making equivalent substitute parts necessary for new designs and ongoing production support.

Substiute Parts

MAX121C/D

Analog Devices Inc./Maxim IntegratedIn Stock: 1071MAX121C/D Datasheet

Current PartRFQ

MAX121CPE+

Analog Devices Inc./Maxim IntegratedIn Stock: 1234MAX121CPE+ Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the MAX121C/D is based on functional equivalence across core electrical and mechanical parameters. The MAX121CPE+ qualifies as a direct substitute because it maintains identical specifications for resolution (14-bit), sampling rate (308 kSPS), input configuration (1 single-ended input), data interface (SPI), and architecture (SAR with S/H-ADC). Both parts share the same base product number (MAX121) and are manufactured by Analog Devices Inc./Maxim Integrated.

The primary difference between these parts is packaging: the MAX121C/D is supplied as a die, while the MAX121CPE+ is packaged in a 16-PDIP (0.300", 7.62mm) through-hole format. This packaging difference makes the MAX121CPE+ suitable for applications where a packaged component is required, while the die form factor of the original part is no longer available.

Both parts maintain compliance with ROHS3 and REACH standards, ensuring regulatory compatibility for new designs.

Parameter Comparison

Engineering Selection Recommendations

The MAX121CPE+ is the recommended substitute for the obsolete MAX121C/D. Both components share identical functional specifications for data acquisition applications requiring 14-bit resolution at 308 kSPS sampling rates with single-ended input and SPI interface.

The MAX121CPE+ is currently in active production status, ensuring long-term availability and supply chain stability. Both parts maintain ROHS3 compliance and REACH unaffected status, meeting regulatory requirements for new designs.

The primary consideration for component selection is the packaging format. The MAX121CPE+ is supplied in a 16-PDIP through-hole package, which differs from the die form factor of the original part. Applications originally designed around die-level integration will require board-level redesign to accommodate the packaged component. Conversely, applications requiring a packaged IC will find the MAX121CPE+ directly compatible with standard through-hole PCB assembly processes.

Frequently Asked Questions (FAQ)

Q: Can the MAX121CPE+ directly replace the MAX121C/D in existing designs?

A: Functionally, yes. Both parts are electrically identical with 14-bit resolution, 308 kSPS sampling rate, single-ended input, and SPI interface. However, the MAX121CPE+ is packaged in a 16-PDIP through-hole format, while the MAX121C/D is a die. PCB layout and assembly processes must be adapted accordingly.

Q: What is the key difference between these two parts?

A: The MAX121C/D is supplied as a bare die for hybrid circuit integration, while the MAX121CPE+ is a packaged 16-PDIP component for standard PCB assembly. All electrical specifications remain identical.

Q: Are both parts compliant with current regulatory standards?

A: Yes. Both the MAX121C/D and MAX121CPE+ are ROHS3 compliant and REACH unaffected, meeting current regulatory requirements for electronic components.

Q: Why is the MAX121C/D obsolete?

A: The die form factor has been discontinued by the manufacturer. The MAX121CPE+ packaged version remains in active production and is the recommended path forward for new designs and production continuity.

Q: What supply voltage range does the MAX121CPE+ support?

A: The MAX121CPE+ operates with 5V analog and digital supply voltages. The digital supply range is specified as 5V nominal, compared to the MAX121C/D's 4.75V ~ 5.25V range. Both parts require stable 5V supply for proper operation.

Q: Is the SPI interface identical between both parts?

A: Yes. Both the MAX121C/D and MAX121CPE+ use SPI data interface with identical protocol specifications, ensuring software and firmware compatibility.