70 MHz ARM7 in a 48-HVQFN — what fits
The LPC2103FHN48H/6518: 16/32-bit ARM7 MCU clocked at 70 MHz, with 32 KB Flash and 8 KB SRAM. It has an 8-channel 10-bit ADC, 32 GPIO, and serial interfaces I²C, SPI, SSP, UART in a 48-HVQFN package.
Industrial temperature and supply range
The 1.65 V minimum supply means the MCU stays alive during a Li-ion discharge down to empty — no brownout reset from the battery alone.
No official second-source alternate is listed for this exact order code, but the LPC2100 family shares pin-compatible density options if a future Flash/RAM upgrade is needed.