The STC15W404AS with TSSOP-20 Microcontroller Units (MCUs/MPUs/SOCs) ROHS was manufactured by STC, and it is a Single-Chip 8051-Core MCU. It has advanced circuitry designed for high-speed operation with low power consumption. It includes an 8051-compatible CPU, UART, Timers, Pulse-Width-Modulation (PWM), SPI, I2C, and an A/D Conversion Unit (ADC). It also includes a Parallel I/O port and 32Kbytes of Internal Flash ROM. The STC15W404AS with TSSOP-20 has an operational voltage range of 2.4V to 5.5V and a temperature range of -40°C to +85°C. It is a RoHS-compliant version, and it meets various standards for environmental compliance.