NXP Semiconductors MKM35Z256VLL7

Overview

MKM35Z256VLL7 from NXP Semiconductors is a 32-bit Arm® Cortex®-M0+ microcontroller optimized for high-accuracy electricity metering, featuring four 24-bit ΣΔ ADCs with programmable gain amplifiers, 256 KB flash/64 KB SRAM, hardware tamper detection with timestamping, and an auto-compensated iRTC. It enables single-chip 1-/2-/3-phase metering designs compliant with WELMEC/OIML recommendations in utility-grade smart meters.

For engineers reviewing the MKM35Z256VLL7 datasheet, MKM35Z256VLL7 pinout, MKM35Z256VLL7 application, or MKM35Z256VLL7 equivalent, key selection criteria include metrology-grade analog front-end performance, secure cryptographic acceleration (MMCAU/AES), low-power RTC with VBAT domain operation, and segment LCD controller support for HMI in energy measurement systems.

Technical Context

The MKM35Z256VLL7 integrates a dedicated Metering Memory Mapped Arithmetic Unit (MMAU) for real-time energy computation and a Memory Mapped Cryptographic Acceleration Unit (MMCAU) supporting AES encryption. Its analog subsystem includes four independent AFE channels with PGA and 24-bit ΣΔ conversion, plus a 16-bit SAR ADC for auxiliary sensing.

Power management is implemented via 13 configurable power modes-including VLLS0 with 261 nA deep-sleep current-and dual-domain clocking (iRTC at 32.768 kHz, core up to 75 MHz). Tamper detection uses hardware-monitored inputs with time-stamped event logging in battery-backed memory.

Key Specifications

Pinout & Package

MKM35Z256VLL7 is housed in a 100-pin LQFP package (14 mm × 14 mm, 0.5 mm pitch), designed for thermal reliability and mechanical stability in utility meter applications. Pin assignments follow NXP's KM35 signal multiplexing scheme with dedicated AFE, tamper, LCD, and communication interface pins.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar electricity metering applications.

Compared with MKM35Z256VLQ7 and MKM35Z512VLL7, the MKM35Z256VLL7 delivers optimal cost-performance balance for standard 1-/3-phase meters-offering full metrology capability in the smallest LQFP footprint without sacrificing security or low-power operation.

Availability

MKM35Z256VLL7 is available at Aetrix Electronics and suitable for smart electricity meters, revenue-grade gateways, and prepayment metering systems requiring stable component supply, long lifecycle support, and certified metrology performance.

Supply support for MKM35Z256VLL7 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

NXP Semiconductors is a global semiconductor leader specializing in secure connectivity solutions for automotive, industrial, and IoT markets, with over 30 years of expertise in embedded processing and analog integration.

The KM35 sub-family, including MKM35Z256VLL7, was engineered specifically for utility-grade electricity metering-integrating metrology AFE, tamper resilience, and secure boot into a single Arm® Cortex®-M0+ platform compliant with WELMEC and IEC 62053 standards.

FAQ

What is the maximum operating frequency of the MKM35Z256VLL7 core?

The MKM35Z256VLL7 features an Arm® Cortex®-M0+ core rated for up to 75 MHz operation under normal run mode conditions. This frequency is sustained across the full –40 °C to +105 °C ambient temperature range and 2.7–3.6 V supply voltage when the AFE is active, enabling deterministic real-time energy computation without throttling.

Does the MKM35Z256VLL7 support hardware-based AES encryption?

Yes, the MKM35Z256VLL7 includes a Memory Mapped Cryptographic Acceleration Unit (MMCAU) that provides hardware-accelerated AES-128 encryption and decryption. This module operates independently of the CPU, allowing secure firmware updates and data-at-rest protection without impacting metrology performance or increasing software overhead in the MKM35Z256VLL7 application.

How many tamper detection inputs does the MKM35Z256VLL7 provide?

The MKM35Z256VLL7 provides four dedicated hardware tamper inputs (PTA0–PTA3), each capable of triggering timestamped event logging in the VBAT-backed memory domain. These inputs meet IEC 62053-31 requirements for secure metering and retain tamper records even during main power loss, ensuring forensic auditability in the MKM35Z256VLL7 design.

What is the lowest power consumption mode available on the MKM35Z256VLL7?

The MKM35Z256VLL7 supports Very Low-Leakage Stop Mode 0 (VLLS0) with typical current draw of 261 nA at 3.0 V and 25 °C. In this mode, the iRTC remains operational with VBAT supply, and tamper detection continues-enabling decade-long battery life in static meters while preserving timekeeping and security functions in the MKM35Z256VLL7 implementation.

Is the MKM35Z256VLL7 pin-compatible with other KM35 family members?

No, the MKM35Z256VLL7 is not pin-compatible with KM35 variants in different packages (e.g., VLQ7) or flash sizes (e.g., MKM35Z512VLL7). While it shares the same 100-pin LQFP footprint as MKM35Z256VLL7R and MKM35Z512VLL7, pin functions are identical only within the same package variant-designers must verify signal mapping against the KM35P144M75SF0RM reference manual for the MKM35Z256VLL7.