RE46C109 Datasheet, PDF (6/9 Pages) Microchip Technology – Voltage Regulator, Voltage Converter and Piezoelectric Horn Driver

RE46C109
Voltage Regulator, Voltage Converter and
Piezoelectric Horn Driver
Product Specification
R&E International
A Subsidiary of Microchip Technology Inc.
Device Operation
(Please refer to the functional block diagram)
The RE46C109 consists of the following main functional blocks: band gap voltage reference, low drop-out voltage
regulator (with over voltage clamp and power supply brownout protection), low battery detection, switched
capacitor 12 volt boost regulator, horn driver and Interconnect logic.
When power is applied the band gap voltage reference and the voltage regulator output are initially enabled. The
low battery detection, horn driver outputs and switched capacitor 12v boost regulator are enabled by TTL
compatible positive logic control inputs.
When the HRNEN (Horn Enable) input is brought to a logic high level, the horn driver outputs as well as the 12v
boost regulator become active. The 12v boost regulator supplies the horn driver outputs. The 12v boost regulator
utilizes a charge pump to boost the Vdd supply input to a regulated 12-volt output. The charge pump consists of
an internal oscillator that is controlled in a voltage comparator feedback configuration.
The low battery detection is enabled and strobed when the LBST input is brought to a logic high level. The LBAT
output is a voltage follower amplifier whose input is determined by a resistor divider across the device supply rails.
© 2009 Microchip Technology Inc.
DS22168A-page 6