HTC750XXX

This circuit HTC750XXX is designed to work as melody generator. HTC750 will play selected melody (selection is done by driving D0 and D1 inputs to low or high value) and once melody is finished it will enter power saving mode which we call Sleep mode. In Sleep mode HTC750 consumes less then few microamps of current. One of possible uses of HTC750 is designing it in doorbell. This device HTC750XXX was designed using our proprietary melody storing scheme to optimize internal memory usage. HTC750 can play up to four melodies. It can directly drive piezo-electrical sound source or with use of external amplifier can drive speakers. Control output is provided to control external relay or power switch. This output goes high for duration of melody and could be used to control the power to HTC750 and amplifier for duration of melody.