USB Key HT68FB550 Characteristics 4K / 8K / 16K16 Flash Program Memory I/O type MCU 256 / 512 / 768 Byte Data Memory USB 2.0 Full Speed Compatible Supports 4 / 6 / 8 Endpoints Supports 3.3V LDO and internal UDP 1.5k pull-high 3.3V resistor Integrated HIRC 12MHz OSC with 0.25% accuracy for USB mode Timer Module PWM output mode used to drive RGB LEDs 2 Integrated Dual SPI and I C serial interface Supports In System Programming – ISP 32768Hz Crystal HT68FB550 RTC IC Application Areas USB Key Battery Application Circuit RTC IC Circuit USB Circuit