USB 2.0 compatible MCUs from Holtek with internal clock support

Holtek has released new Full Speed USB Flash series MCUs, in the form of its I/O type HT68FB540, HT68FB550 and HT68FB560 devices and its A/D type HT66FB540, HT66FB550 and HT66FB560 devices. These devices are new additions to Holtek's new generation 8-bit Flash USB MCUs. The devices include Holtek's high precision oscillator internal clock patented technology, providing the devices with a 12MHz oscillation frequency accuracy of up to ± 0.25% for the USB mode. Using this patented clock technology, the USB function is now fully internal and requires no external components. The microcontrollers also provide input and output pins for voltage conversion to enhance product flexibility. The Flash Memory can withstand up to a million rewrite cycles. The HT66FB5x0 and HT68FB5x0 series are compatible with the USB 2.0 specification and have an operating voltage of 2.2V to 5.5V，an operating temperature of -40℃ to +85℃ thus meeting with industrial specifications. The system clock is derived from either an external crystal or a fully internal high speed RC oscillator circuit with a fixed frequency of 12 MHz. The device range has a Program Memory capacity of 4K, 8K, 16Kx16 and up to 1024 bytes of Data Memory RAM. They all include a Full Speed USB interface with up to 8 USB endpoints as well as 45 bidirectional I/Os, 4 Timer Modules with PWM outputs, dual SPI interfaces, an I2C slave, a ...