P80C557E4EFB

P80C557E4EFB is the ROMless member of Philips' P8xC557E4 family: an 80C51 core with 1024 x 8 of RAM and no mask program ROM, so firmware lives in external memory up to 64 KB. Its peripheral set kept it in industrial service: two standard 16-bit timers plus a third with capture and compare, a 10-bit ADC with eight multiplexed inputs and auto-scanning, two 8-bit PWM channels, five 8-bit I/O ports plus a dedicated input port, I2C, a full-duplex UART, a watchdog, 15 interrupt sources, a PLL oscillator and seconds timer. It runs at 4.5 V to 5.5 V, 3.5 MHz to 16 MHz; this EFB code is the QFP-80 (SOT318-1) package, -40 to +85 °C. Lifecycle note: this Philips-era part is discontinued — NXP no longer lists it — so availability is legacy stock only; treat it as a sustaining buy and confirm date code and traceability; /01-suffixed forms are the same device, different packing. Parameters verified against NXP documentation.