40 MHz ARM Cortex-M3 with 256 KB Flash — what it buys the design
The Infineon CY9AF314NAPMC-GNE2 is a 32-bit ARM Cortex-M3 microcontroller from the FM3 MB9A310A series, clocked at 40 MHz. It carries 256 KB of Flash program memory and 32 KB of RAM, placing it in the mid-range density tier for Cortex-M3 parts — enough for a real-time control loop, a USB stack, and a modest RTOS without external memory. The 2.7 V to 5.5 V supply range is a practical advantage: it runs directly from a 3.3 V or 5 V rail, or from a 3-cell alkaline battery stack, without a regulator. The -40°C to 105°C operating temperature range qualifies it for industrial motor drives, outdoor telecom enclosures, and under-hood automotive auxiliary modules. On-chip peripherals include USB, I²C, SPI, UART/USART, LINbus, and an external bus interface (EBI/EMI), plus 16-channel 12-bit SAR ADC. With 83 general-purpose I/Os in a 100-LQFP package, this part suits control panels, sensor hubs, and human-machine interface applications where a single-chip solution keeps the BOM count low.
Memory and peripheral budget for the BOM
256 KB Flash and 32 KB RAM are the memory envelope for firmware and data. A typical application — say, a brushless DC motor controller with CANopen stack and USB logging — fits comfortably in 128 KB of code space, leaving headroom for field-upgradeable bootloader and diagnostic routines. The 32 KB RAM supports moderate-sized data buffers and a real-time OS kernel with a few tasks. The 16-channel 12-bit SAR ADC samples at rates adequate for current sensing in motor drives or multi-channel temperature monitoring. The DMA controller offloads ADC result transfers and serial communication without CPU intervention, preserving the 40 MHz core for control algorithm execution.
Package and layout fit
The 100-LQFP package (14x14 mm body) with 0.5 mm pitch is a standard footprint that routes easily on a two-layer PCB. The 83 I/Os are distributed around all four sides, giving the layout engineer flexibility in signal routing. No exposed thermal pad — junction-to-ambient thermal performance relies on the leadframe and copper pour area.
Lifecycle and sourcing posture
The CY9AF314NAPMC-GNE2 carries an Active lifecycle status with ROHS3 compliance. This part is suitable for both new design-ins and ongoing production without obsolescence risk in the near term. For dual-sourcing or a higher-performance variant, the CY9BF314RPMC-G-JNE2 is a pin-compatible sibling in the FM3 MB9B310R series, running at 144 MHz with the same 256 KB Flash and 100-LQFP footprint.