SemiconductorThe HT66F03C is a surface mount 8-pin 150mil RoHS SOP-8 manufactured by Holtek Semiconductor. It is a flash micro-controller with integrated 8-bit CPU, ROM, RAM, I/O ports, Timer/Counter and various other peripherals, making it suitable for a wide range of applications. The flash memory is 8K bytes, which is non-volatile and can store data, even when power is removed from the device. The device is compatible with the industry standard 8051 instruction set and has an on-chip debug interface for programming and in-circuit debugging. It operates with a power supply range of 2.2V to 6.0V and has an operating temperature range of -40°C to +85°C.