NXP Semiconductors MKM35Z256VLQ7

Overview

MKM35Z256VLQ7 from NXP Semiconductors is a 32-bit Arm® Cortex®-M0+ microcontroller optimized for high-accuracy electricity metering, featuring four 24-bit sigma-delta ADCs with programmable gain amplifiers, 256 KB flash/64 KB SRAM, hardware tamper detection with timestamping, and integrated segment LCD controller. It enables single-chip 1-/2-/3-phase meter designs compliant with WELMEC/OIML recommendations.

For engineers reviewing the MKM35Z256VLQ7 datasheet, MKM35Z256VLQ7 pinout, MKM35Z256VLQ7 application, or MKM35Z256VLQ7 equivalent, this device delivers metrology-grade analog front-end performance, secure cryptographic acceleration (AES/MMCAU), low-power RTC with battery backup, and support for neutral disconnect use cases in utility-grade smart meters.

Technical Context

The MKM35Z256VLQ7 integrates a dedicated Metering-specific Memory Mapped Arithmetic Unit (MMAU) for real-time energy computation and a hardware-based tamper detection subsystem that logs events with iRTC timestamps. Its AFE domain operates at 2.7–3.6 V and supports up to 6.5 MHz modulator clocking for precise current/voltage sampling.

It implements 13 configurable power modes-including deep-sleep mode drawing just 261 nA-and features dual-domain clocking: 75 MHz core/system clocks for active metrology processing and independent 32.768 kHz crystal oscillator in the VBAT domain for tamper-resilient timekeeping.

Key Specifications

Pinout & Package

MKM35Z256VLQ7 uses a 144-pin LQFP package (20 mm × 20 mm, 0.5 mm pitch) with exposed thermal pad. Pin assignments include dedicated AFE input pairs (PTB7/PTE3/PTK4), tamper detection inputs (TAMPER0–TAMPER3), segment/common LCD outputs, and dual-domain power pins (VDD/VDDA/VBAT).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MKM35Z256VLQ7, MKM35Z256VLL7 offers identical metrology performance in a smaller footprint but sacrifices 27 GPIOs and LCD drive capacity, while STM32G0B1RET6 demands external analog components and lacks hardware tamper timestamping-increasing system-level validation effort and bill-of-materials complexity.

Availability

MKM35Z256VLQ7 is available at Aetrix Electronics and suitable for smart electricity metering, revenue-grade energy monitoring, and secure prepayment metering requiring stable component supply and long-term lifecycle support.

Supply support for MKM35Z256VLQ7 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 company headquartered in Eindhoven, Netherlands, specializing in secure connectivity solutions for automotive, industrial, and IoT markets.

The KM35 sub-family is designed specifically for metrology applications, integrating high-precision AFE, tamper resilience, and low-power operation to meet global electricity metering standards including IEC 62053, WELMEC, and ANSI C12.

FAQ

What is the maximum AFE modulator clock frequency supported by MKM35Z256VLQ7?

The MKM35Z256VLQ7 supports up to 6.5 MHz AFE modulator clock frequency when operating at 1.7–3.6 V supply. This enables high-resolution sampling for Class 0.2 electricity meters per IEC 62053-22. The AFE clock can be sourced internally via PLL or externally through dedicated pins (PTB7/PTE3/PTK4), and timing specifications are validated across –40 °C to +105 °C ambient temperature.

Does MKM35Z256VLQ7 include hardware-accelerated cryptographic functions?

Yes, MKM35Z256VLQ7 includes a Memory Mapped Cryptographic Acceleration Unit (MMCAU) supporting AES-128 encryption/decryption, a NIST SP800-90-compliant Random Number Generator (RNGA), and Programmable Cyclic Redundancy Check (PCRC). These modules operate independently of the Cortex-M0+ core, enabling secure DLMS/COSEM communications and firmware authentication without compromising metrology throughput.

How many GPIOs does MKM35Z256VLQ7 provide, and what is their voltage tolerance?

MKM35Z256VLQ7 provides 99 general-purpose I/O pins in its 144-LQFP package. Digital I/Os tolerate voltages from –0.3 V to VDD + 0.3 V (max 3.9 V at 3.6 V supply), with input hysteresis of 0.06 × VDD. All GPIOs support interrupt generation, digital glitch filtering, and configurable pull-up/pull-down resistors (30–60 kΩ), and selected pins are 5 V tolerant when configured as inputs only.

What low-power modes are available on MKM35Z256VLQ7, and what is the lowest achievable current draw?

MKM35Z256VLQ7 offers 13 power modes, including Very Low-Leakage Stop Mode 0 (VLLS0) with POR detect disabled, achieving 261 nA typical current draw at 3.0 V and 25 °C. In VBAT domain operation with iRTC active and 32 kHz oscillator enabled, average current is 1.42 μA at 3.0 V. These modes are fully characterized across –40 °C to +105 °C and support rapid wake-up (<382 μs from VLLSx to RUN) for responsive tamper response.

Is MKM35Z256VLQ7 qualified for electricity metering standards such as WELMEC and OIML?

Yes, MKM35Z256VLQ7 is explicitly designed to support compliance with WELMEC R 46 and OIML R 46 recommendations for active energy meters. Its metrology subsystem-including 24-bit sigma-delta ADCs, hardware tamper detection with timestamping, single-point calibration, and temperature-compensated reference-enables Class 0.2 accuracy per IEC 62053-22. NXP provides metrology reference designs and calibration libraries aligned with these standards.