The TPS8802 integrates a boost converter, analog supply LDO, microcontroller supply LDO, photoelectric chamber analog front end (AFE), carbon monoxide sensor AFE, interconnect driver, piezo horn driver, analog multiplexer, and digital core. The high integration greatly reduces component count in smoke alarms and carbon monoxide alarms. The TPS8802 can be powered from a variety of sources:

• 9-V battery
• 3-V battery
• 2-V to 15-V DC supply
• DC supply with battery backup

The two LED drivers have highly configurable temperature compensation to support IR and blue LEDs over a wide range of currents. The wide bandwidth of the photo-amplifier saves power due to reduced LED on-time. The CO amplifier has integrated gain resistors. The horn driver is compatible with two-terminal or three-terminal piezo horns, and the three-terminal self-resonant mode is tunable to maximize piezo loudness. The wired interconnection driver allows multiple smoke alarm units to communicate alarm conditions. Each block is highly configurable with the digital core I²C interface, supporting on-the-fly adjustment of amplifier gains, regulator voltages, and driver currents. Digital features such as sleep mode, under-voltage boost enabling, and one-time boost charging are designed to reduce power consumption for the 10-year battery alarms. Configurable status and interrupt signal registers alert the MCU of fault conditions such as under-voltage, over-temperature, and interconnection alerts.