FM33LG045A FMSH 256KB Flash 32KB RAM Low-Power MCU LQFP48

The FMSH FM33LG045A is a low-power mcu that runs from 1.65V~5.5V over -40℃~+105℃. It carries 256KB of Flash and 32KB of RAM. The package is LQFP48.

Key Specifications

Design Notes

• Low-power MCUs spend most of their life in sleep. Compare the datasheet current figures in the modes you actually use — active, sleep, and RTC-only — rather than the headline number.
• Flash and RAM figures are the on-chip totals. The LCD segment buffer and any bootloader consume part of the RAM, so confirm the usable remainder against your firmware.
• ISO 7816 channels are driven from the same pin group as the UARTs on some parts. Check the pin-out table before assuming all channels are simultaneously available.
• Operating voltage range matters at both ends: the low end sets the battery cut-off, the high end decides whether the part survives a programming supply or a failing cell stack.

Common Questions

How much program memory is available?

256KB of on-chip Flash, with 32KB of 32KB. Part of the 32KB is reserved for the LCD buffer and the bootloader, so confirm the remainder against the firmware image.

What is the operating voltage range?

1.65V~5.5V. The low end sets the battery cut-off point; the high end covers programming and transient conditions.

How many serial channels does it have?

1. Check the pin-out table for channels that share pins with the ISO 7816 interface before allocating them in firmware.

What is the operating temperature range?

-40℃~+105℃, which covers outdoor meter enclosures without additional heating.