ATSAM4CMS4CB-AU - Dual-Core 120MHz MCU 256KB | Microchip
MPN: ATSAM4CMS4CB-AU β Active| Qty | Unit Price | Extended |
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| 1 | $0 | $0.00 |
| 10 | $0 | $0.00 |
| 100 | $0 | $0.00 |
| 500 | $0 | $0.00 |
| 1,000 | $0 | $0.00 |
ATSAM4CMS4CB-AU Overview
A microcontroller unit (MCU) integrates a processor core, program memory, data memory, and peripheral set on a single chip, forming the compute layer of an embedded system. The SAM4CM series extends Microchip's (formerly Atmel's) SAM4C family into the smart metering domain, adding a metrology analog front end (AFE) and hardware cryptography to the general-purpose Cortex-M4 MCU architecture for single-chip energy measurement platforms.
Key features of the ATSAM4CMS4CB include the dual-core Cortex-M4/M4F architecture, where one core handles application firmware and the second core can be dedicated to metrology or security tasks, delivering deterministic real-time behavior at up to 120 MHz. The integrated crypto engine accelerates authentication and encryption for smart-grid communication stacks, while the built-in single-phase, 4-channel metrology AFE supports residential and industrial metering up to class 0.2 accuracy over a dynamic range of 3000:1, according to Microchip's product documentation.
Technical depth: the SAM4CM combines a high-performance RISC pipeline with FPU support (Cortex-M4F), RAM totaling 128KB, and a peripheral set suited to metering and communications. The device operates from a 1.2V core domain with integrated regulators, simplifying power-tree design in single-phase meters.
Typical applications include residential and single-phase electricity meters, smart-grid data concentrators, and secure industrial metrology nodes, where the combination of metrology AFE, cryptography, and dual-core processing eliminates a separate metrology IC.
Design consideration: budget Flash and RAM early - the 256KB Flash / 128KB RAM of the CB density variant should be verified against bootloader plus application footprint before PCB commitment.
This page synthesizes distributor listings, family-level cross-reference data, and practical selection notes beyond what any single datasheet page provides.
Drop-in alternatives for ATSAM4CMS4CB-AU β same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with ATSAM4CMS4CB-AU (same form factor and footprint) β differing in RoHS Status, Package, Packaging, Core Processor, Flash Memory.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
ATSAM4CMS4CA-AU
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
ATSAM4CMS8CB-AU
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
ATSAM4CMS8CA-AU
β Drop-In β οΈ εζ°εΎ ιͺθ―β In Stock
$8.45 / Unit
View Datasheet βATSAM4CMC4CB-AU
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
ATSAM4CMS4CB-AU Maximum Ratings & Electrical Characteristics
| Core Architecture | 32-bit dual-core ARM Cortex-M4/M4F |
| Maximum Clock Frequency | 120 MHz |
| Flash Memory | 256 KB (256K x 8) |
| SRAM | 128 KB |
| Core Supply Voltage | 1.2 V |
| Metrology Front End | Single-phase, 4-channel AFE |
| Metrology Accuracy | Class 0.2, dynamic range 3000:1 |
| Hardware Security | Integrated crypto engine (CRYPTO AFE) |
| Package | 100-LQFP (14 x 14 mm) |
| Mounting Type | Surface Mount |
| Packaging | Tray |
| Series | SAM4CM (SAM4C family) |
| Application Segment | Residential and single-phase smart metering |
| RoHS Status | unknown |
ATSAM4CMS4CB-AU 100-lqfp (14 x 14 mm) Pin Configuration Guide
Pin configuration for ATSAM4CMS4CB-AU (100-lqfp (14 x 14 mm) package). This digital IC includes GPIO, communication interfaces (UART, SPI, I2C), and power pins. Refer to the manufacturer datasheet for alternate pin functions and configuration options. Essential for embedded system design and PCB layout.
No detailed pinout data available for ATSAM4CMS4CB-AU.
Refer to the datasheet for full pin configuration.
Typical Applications
ATSAM4CMS4CB-AU is suitable for 6 applications: Residential Single-Phase Smart Meters, Smart Grid Data Concentrators, Industrial Energy Submeters and Panel Meters, Secure IoT Metering Nodes, Building Automation Energy Monitoring, Solar String and Inverter Monitoring.
Residential Single-Phase Smart Meters
The ATSAM4CMS4CB-AU is purpose-built for residential single-phase electricity metering: its integrated 4-channel metrology AFE achieves class 0.2 accuracy over a 3000:1 dynamic range, per Microchip's product documentation, covering both low-current standby loads and high-current peak loads on a single chip. One Cortex-M4F core can run the metrology computation loop continuously while the second core executes the DLMS/COSEM communication stack and firmware-update logic, giving deterministic measurement even during RF activity. The 256KB Flash holds metering firmware plus secure bootloader, and 128KB SRAM buffers load-profile logs. The hardware crypto engine protects billing data and authentication keys. This single-chip approach removes a discrete metrology IC, cutting BOM cost and calibration points.
Recommended
Smart Grid Data Concentrators
In smart-grid data concentrators that aggregate meter reads over PLC, RS-485, or RF mesh networks, the ATSAM4CMS4CB-AU's dual-core 120 MHz Cortex-M4/M4F architecture separates protocol handling (core 1) from data management and security (core 2), preventing communication bursts from disturbing timing-critical tasks. The hardware crypto engine accelerates TLS-class session setup for head-end system links, while 128KB SRAM supports message queuing and store-and-forward buffering during backhaul outages. The 100-LQFP (14x14 mm) package provides enough I/O for multiple communication interfaces and status indicators. Its industrial-grade pedigree from the metering domain suits the unconditioned thermal environments concentrators typically face in cabinets and substations.
Recommended
Industrial Energy Submeters and Panel Meters
Industrial submetering panels require billing-grade measurement (class 0.2) across a wide load dynamic range, exactly the 3000:1 window the SAM4CM metrology AFE delivers, per Microchip documentation. The ATSAM4CMS4CB-AU processes current and voltage channel samples on its dedicated Cortex-M4F core at 120 MHz, sustaining accuracy without host-CPU load, while the primary core handles Modbus/RS-485 interfaces and local displays. The 256KB Flash accommodates multi-tariff firmware, and the crypto engine supports authentication for prepaid-metering schemes common in commercial facilities. The 100-LQFP industrial package and SAM4C family heritage simplify design-in for panel builders seeking a single-metering-MCU platform across product tiers.
Recommended
Secure IoT Metering Nodes
IoT-connected metering nodes combine measurement, edge processing, and secure cloud communication - a workload the ATSAM4CMS4CB-AU handles with its dual-core split: metrology on one Cortex-M4F core, network stack and JSON/CBOR payload preparation on the other at up to 120 MHz. The integrated crypto engine performs the symmetric operations required by LPWAN link layers, and the 100-LQFP footprint leaves board room for RF modules or power-line modem front ends. 256KB Flash supports OTA-updatable application images with a bootloader reserve, and 128KB SRAM provides TLS session buffering. Because the metrology AFE is on-chip, the same PCB serves both wired-meter and IoT-gateway derivatives, reducing platform qualification effort.
Recommended
Building Automation Energy Monitoring
Building energy management systems deploy many branch-circuit monitors, so cost and integration matter: the ATSAM4CMS4CB-AU integrates the metrology AFE and MCU, replacing a two-chip solution and lowering per-point cost. Its 3000:1 dynamic range captures both the small standby flows of individual circuits and peak HVAC loads with class 0.2 accuracy. The second Cortex-M4F core sustains continuous waveform sampling at 120 MHz while the main core serves BACnet/Modbus queries over RS-485 or Ethernet-attached companions. The crypto engine supports secure commissioning of multi-tenant buildings. Tray packaging suits the medium-volume production typical of panel-monitor OEMs, and the SAM4CM family offers memory-grade upgrade paths on the identical 100-LQFP footprint.
Recommended
Solar String and Inverter Monitoring
Distributed solar installations need per-string energy metering with secure reporting to aggregation gateways. The ATSAM4CMS4CB-AU's metrology AFE measures DC/AC-side channel quantities with its 4-channel front end, and its dual-core 120 MHz architecture runs MPPT-supporting calculations concurrently with communication stacks without core contention. The hardware crypto engine authenticates data sent to utility or fleet-management servers, an increasingly common grid-code requirement, and 256KB Flash holds firmware with OTA reserve. The industrial-temperature SAM4CM design targets rooftop combiner boxes where ambient temperatures swing widely. Using one metering-MCU platform across meter, submeter, and solar-monitor product lines consolidates firmware, calibration tooling, and supply agreements.
Recommended
Recommended Products Summary
Engineering reference data for ATSAM4CMS4CB-AU β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATSAM4CMS4CA-AU | ATSAM4CMS8CB-AU | ATSAM4CMS8CA-AU | ATSAM4CMC4CB-AU |
|---|---|---|---|---|---|
| Package | 100-LQFP (14x14 mm) | 100-LQFP (14x14 mm) - same | 100-LQFP (14x14 mm) - same | 100-LQFP (14x14 mm) - same | 100-LQFP (14x14 mm) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Core | Dual-core ARM Cortex-M4/M4F, 120 MHz | Dual-core ARM Cortex-M4/M4F, 120 MHz | Dual-core ARM Cortex-M4/M4F, 120 MHz | Dual-core ARM Cortex-M4/M4F, 120 MHz | Dual-core ARM Cortex-M4/M4F, 120 MHz |
| Flash Memory | 256 KB | 256 KB | 512 KB | 512 KB | 256 KB |
| Metrology AFE | Single-phase, 4-ch, class 0.2, 3000:1 | Single-phase, 4-ch, class 0.2, 3000:1 | Single-phase, 4-ch, class 0.2, 3000:1 | Single-phase, 4-ch, class 0.2, 3000:1 | CM variant metrology configuration |
| Hardware Crypto | Yes (CRYPTO AFE) | Yes | Yes | Yes | Yes |
| Upgrade Path | Baseline density (CB) | Same memory grade, alternate RAM density | Pin-compatible 2x memory upgrade | Largest memory grade, same footprint | Extended metrology variant, same memory |
Key Differentiators
- Integrated metrology AFE replaces separate metering IC (vs ATSAM4C (standard family, non-CM))
- Baseline memory density lowers unit cost (vs ATSAM4CMS8CB-AU)
- Dual-core architecture isolates metrology from application load (vs Single-core Cortex-M4 metering MCUs)
Design Notes
Verify memory density against the ordering code before PCB release: the SAM4CM family encodes Flash and RAM grades in the part number (S4 = 256KB Flash class, CB = 128KB RAM grade). Ordering or substituting the wrong density letter yields a pin-compatible device with insufficient memory, discovered only at firmware bring-up. Cross-check the exact variant against Microchip's SAM4CM ordering-code table in the official datasheet, and lock the MPN in the BOM with the full suffix including the -AU (LQFP-100, tray, industrial) package code.
Design the power tree around the 1.2V core domain specified for the SAM4CM family, using the on-chip regulation features described in the datasheet power management section rather than an external 1.2V rail unless the datasheet variant requires it. In metering designs, separate the analog supply feeding the metrology AFE from the digital rail with an RC filter or ferrite bead; class 0.2 accuracy over a 3000:1 dynamic range makes AFE supply noise the dominant error source at low currents. Follow the reference design layout in the SAM4CM evaluation kit documentation.
For the 100-LQFP (0.5 mm pitch, 14x14 mm), use a 4-layer stack with a solid ground plane under the device; fan out the metrology AFE analog pins (current channel inputs and voltage sense) on a quiet corner of the board away from switching supplies and communication transceivers. Keep crystal and decoupling capacitors within 3 mm of their pins. Because SAM4CM family members share the footprint, reserve the same land pattern for ATSAM4CMS8 density upgrades to enable a firmware-only respin later.
Compliance Information
Compliance status was not captured in the verified web data; consult Microchip's official product page and environmental data sheets for the ATSAM4CMS4CB-AU before export or automotive deployment.