Microchip Technology MCP98242T-CE/MNY

Overview

MCP98242T-CE/MNY from Microchip Technology is a JEDEC JC42.4-compliant digital temperature sensor with integrated 256-byte serial EEPROM for SPD applications, operating from 3.0V to 3.6V, delivering ±0.5°C typical accuracy from +75°C to +95°C, 200 µA typical operating current, and I²C/SMBus-compatible 2-wire interface - deployed in DDR3/DDR4 DIMM modules for real-time thermal monitoring and vendor data storage.

For engineers reviewing the MCP98242T-CE/MNY datasheet, MCP98242T-CE/MNY pinout, MCP98242T-CE/MNY application, or MCP98242T-CE/MNY equivalent, this page delivers verified package mapping (UDFN-8), confirmed pin functions (A0–A2, SDA, SCL, Event, VDD, GND), JEDEC-compliant thermal accuracy bands, EEPROM write-protection architecture, and validated alternative options for memory module thermal sensing.

Technical Context

The MCP98242T-CE/MNY integrates a band-gap temperature sensor with a ΔΣ ADC and user-programmable registers for boundary-triggered event output, supporting 0.25°C resolution (power-up default) and configurable hysteresis (0°C/1.5°C/3.0°C/6.0°C). Its dual-function architecture separates temperature measurement (read-only TA register) from EEPROM data storage (256×8-bit, lower 128 bytes permanently or reversibly write-protected).

It implements JEDEC JC42.4 Mobile Platform Memory Module Thermal Sensor requirements, including programmable TUPPER/TLOWER/TCRIT trip points, active-high/active-low Event polarity selection, comparator/interrupt output mode, and SMBus time-out (40 ms typical) - all accessible via standard I²C protocol with up to eight devices on one bus using A0–A2 address pins.

Key Specifications

Pinout & Package

UDFN-8 package with exposed thermal pad (EP), dimensions 2.0 mm × 3.0 mm × 0.55 mm (height), EP internally connected to GND and requiring PCB connection to system ground plane for thermal performance and EMI control.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar temperature sensor + SPD EEPROM applications.

Compared with AT30TS74-MA8Y and MCP9808-E/MS, the MCP98242T-CE/MNY uniquely combines JEDEC JC42.4 compliance, SPD-tailored EEPROM protection, and triple-trip-point event logic - making it the only qualified solution for DDR3/DDR4 DIMM thermal management where standards adherence and data security are mandatory.

Availability

MCP98242T-CE/MNY is available at Aetrix Electronics and suitable for DDR3/DDR4 DIMM modules, laptop memory subsystems, and server memory riser cards requiring stable component supply, JEDEC-compliant thermal sensing, and secure SPD data storage.

Supply support for MCP98242T-CE/MNY includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Microchip Technology Inc. is a leading provider of microcontrollers, analog components, and memory solutions, headquartered in Chandler, Arizona, with global design and manufacturing operations.

The MCP98242 product line was engineered specifically for JEDEC JC42.4-compliant memory module thermal monitoring and Serial Presence Detect (SPD) data storage - targeting DDR3/DDR4 DIMM manufacturers needing integrated, standards-certified sensor+EEPROM functionality.

FAQ

What is the primary application of the MCP98242T-CE/MNY?

The MCP98242T-CE/MNY is primarily designed for JEDEC JC42.4-compliant thermal monitoring and Serial Presence Detect (SPD) data storage in DDR3 and DDR4 DIMM modules. It provides accurate temperature readings and secure 256-byte EEPROM storage for vendor identification, memory timing parameters, and configuration data - all in a single UDFN-8 package compatible with high-density memory board layouts.

Does the MCP98242T-CE/MNY support I²C communication at 400 kHz?

No, the MCP98242T-CE/MNY supports I²C/SMBus communication only up to 100 kHz, as specified in its timing characteristics (fSC = 10–100 kHz). Attempting 400 kHz operation violates the device's electrical specifications and may result in unreliable register reads/writes or EEPROM corruption. The 100 kHz limit ensures robust operation under SMBus timing constraints and noise immunity in memory module environments.

How is the EEPROM write-protection implemented in the MCP98242T-CE/MNY?

The MCP98242T-CE/MNY implements two-tier EEPROM write-protection: the lower 128 bytes (addresses 00h–7Fh) support either Permanent Write-Protection (PWP) or Software Reversible Write-Protection (SWP) via high-voltage programming (8–12 V applied to A0), while the upper 128 bytes (80h–FFh) remain fully writable. This architecture safeguards critical SPD vendor data while allowing runtime updates to application-specific fields.

What is the function of the Event pin on the MCP98242T-CE/MNY?

The Event pin on the MCP98242T-CE/MNY is an open-drain output that asserts when ambient temperature crosses user-programmed boundaries (TUPPER, TLOWER, or TCRIT). It is configurable as an active-high or active-low comparator output for direct fan control, or as an interrupt signal for microprocessor-based thermal management - with hysteresis settings (0°C/1.5°C/3.0°C/6.0°C) to prevent oscillation near trip points.

Is the MCP98242T-CE/MNY pin-compatible with other Microchip temperature sensors like the MCP9808?

No, the MCP98242T-CE/MNY is not pin-compatible with the MCP9808-E/MS or other members of Microchip's temperature sensor family. While both use 8-pin packages, the MCP98242T-CE/MNY (UDFN-8) assigns A0–A2 as address pins and includes dedicated Event output, whereas the MCP9808-E/MS (MSOP-8) uses different pin assignments and lacks SPD-specific features. PCB layout and firmware must be redesigned for substitution.