ROHM’s latest low-power MCU includes Class D speaker amp



ML610Q304 MCU

LAPIS Semiconductor, a ROHM Group Company, has recently announced the development of a low-power microcontroller that integrates an 8bit low power MCU core, speech synthesis circuit, high efficiency Class D speaker amp, non-volatile memory, and oscillator circuit on a single chip, making audio playback possible by simply connecting to a speaker.

The ML610Q304 also provides hardware-based audio playback operation that minimizes the load placed on the MCU for system control processing, and the newly designed high-efficiency Class D amp reduces current consumption during audio playback by approx. 40% while maintaining volume and is easier to incorporate into battery-driven devices.

In recent years a growing number of electronic products are adding voice playback functionality, particularly battery-driven devices that require increased miniaturization and lower power consumption for longer operating life. In addition, improvements in sensor technology along with greater awareness for safety and security have resulted in the increased adoption of alarm equipment that demand redundant safety measures such as advanced detection of abnormal audio playback in order to ensure reliable performance during emergencies and other unforeseen events.

To meet the growing need for lower power consumption in compact portable devices, LAPIS Semiconductor will continue to expand its low power microcontroller lineup and contribute to society through energy-saving products, solutions, and initiatives.


Key Features
1) Hardware-based voice playback function simplifies design
Voice playback operation is performed using hardware, which significantly lightens the load on the MCU for system control processing and simplifies playback considerably.
2) 40% less current consumption during voice playback (vs. our conventional products)
A class-leading low power consumption 8bit microcontroller is integrated along with a newly developed Class D speaker amp that provides digital output, resulting in higher power efficiency and 40% less current consumption during voice output compared with conventional analog Class AB speaker amps – while maintaining volume levels. (*based on LAPIS Semiconductor evaluation criteria).
3) Monolithic design with integrated microcontroller and audio playback function reduces the number of parts required and contributes to device miniaturization
All functions required for audio playback are incorporated into a single chip, including a low-power MCU, speech synthesis circuit, high efficiency Class D speaker amp, non-volatile memory, and high accuracy oscillator circuit. Offered in a compact (5mm x 5mm) 28pin package (WQFN) that contributes to end-product miniaturization.

Multiple fail-safe functions provide superior reliability
1) Speaker terminal disconnection detection
Detects no-playback condition due to disconnection between the microcontroller and speakers by monitoring for changes in resistance value between the speaker terminals and can alert users beforehand by lighting up LEDs.
2) Speaker terminal short-circuit detection
Detects no-playback condition due to short-circuit by monitoring the voltage level of the speaker terminals and shuts down operation in order to prevent possible damage.
3) Class D speaker amp overcurrent prevention
Ensures that the sound generator circuit (PWM circuit) does not stay fixed at the H level for over a specified amount of time in order to prevent excessive heat generation due to overcurrent.

A complete support system is offered, including a reference board (ML610Q304) and software development environment that facilitate evaluation, as well as tools and manuals which can be downloaded from the website (registration required).

Additional Features
- Built-in original high-performance 8bit RISC core
- Integrated high efficiency Class D speaker amp (3.0V: 0.45W, 5.0V: 1.0W)
- Multiple fail-safe functions (speaker disconnection/short-circuit detection, Class D speaker amp overcurrent prevention)
- High-precision oscillation: 8.192MHz, 32.768kHz [±1.5% (-10 to 50℃), ±3.0% (-40 to 85℃)]
- 96KB Flash
- 2KB data Flash
- 8bit timer x 4 (two 8bit timers can be used as a 16bit timer)
- 3ch 10bit A/D converter
- Operating frequency: 27kHz to 8.4MHz
- Operating temperature range: -40 to 85℃
- Power supply voltage: 2.0 to 5.5V
- Compact WQFN28 package

LAPIS Semiconductor

ROHM Semiconductor