The RE46C105 is a piezoelectric horn driver with a voltage regulator and an open drain NMOS driver suitable for use with a light emitting diode. It is intended for 9V battery applications which require a low voltage logic supply. The regulator can be operated at either 3.3V or 5V. The horn feedback control pin is designed for use with self-oscillating piezoelectric horn but can also be used in direct drive applications. A low battery detection circuit is also provided.