1.Can external memory be used when the required time exceeds 120 seconds?
Yes, the chip automatically mounts external memory upon power-up, with external priority over internal.
Megaphone (Handheld Bullhorn)
A megaphone (handheld bullhorn) is a portable voice amplification device. It works by capturing the human voice through a microphone, processing it via audio chip algorithms, and driving a speaker to amplify sound for long-distance transmission. This solution is based on the M216A4 chip, supporting 48K high-definition amplification, recording loop playback, alarm sound effects, and other functions. It is widely used in handheld megaphones, amplification speakers, voice prompt devices, and recording broadcast speakers.
Features
Professional-grade dedicated chip for megaphonesSingle chip supports up to 120 seconds of internal recording48KHz full-chain high-definition audioRecording loop playback functionAlarm/siren modeSupports USB/TF card music playbackMulti-level precision volume adjustmentBuilt-in Class-D amplifierSupports U盘 OTA repeat upgrade
Specifications
Main IC
M216A4
Package
SOP16
CPU Architecture
32-bit Dual-Issue DSP, 240MHz
On-chip SRAM
52KB SRAM (20KB shared cache)
ADC Sampling Rate
8kHz～48kHz, supports 48K high-definition megaphone & recording
Audio Channel
1×ADC, 1×DAC(8~96kHz), Built-in Class-D Amp
Built-in Amplifier
500mW @4Ω (supports external power amp)
Audio SNR
ADC/DAC SNR ≥96dB
Recording Function
On-chip recording, up to 120 seconds, supports 48K high-definition recording
Audio Algorithm
Noise reduction for megaphone & recording, DSP anti-howling
Audio Format
MP3, WAV
Storage Media
TF Card, USB Disk, SPI Flash
Main Functions
48K high-definition megaphone, voice speaking, DSP anti-howling, record & loop playback, alarm tone, local audio playback, multi-language voice prompt
Operating Voltage
1.8V~5.5V
Low Power
Soft-off current ＜3μA
Operating Temp.
-20℃ ~ +85℃
Applications
Handheld megaphone, loudspeaker, voice prompt device, recording speaker
Solution (1)
Low-power voice recording module, chip directly drives a 0.5W speaker; supports on-chip recording and voice prompt playback; a single chip accomplishes the product function, delivering extreme cost-effectiveness. Supports 1.8-3.3V or 3.3-5.5V power supply.
Solution (2)
External amplifier solution: chip pin 9 DAC output, pin 14 used as amplifier mute control.
Solution (3)
High sound quality, long recording and playback time, external SPI FLASH, TF, USB. External amplifier and independent microphone power supply, supports amplification with lower noise floor; recording time depends on the SPI FLASH size.
SPI FLASH circuit, automatically reads memory size.
TF card circuit, supports up to 128G memory card.
ADK circuit
FAQ
2.What types of products is the M216A4 suitable for?
Mainly targeted at scenarios requiring clear amplification and voice playback, such as megaphones, loudspeakers, vehicle/emergency broadcasting, and portable voice announcement devices.
3.Which audio formats and storage methods are supported?
Supports MP3 and WAV format decoding and playback; can read from three storage media: TF card, SPI Flash, and USB.
4.How to use the internal recording function? How long can it record?
The chip features a built-in recording function, with a maximum internal recording time of 100 seconds per chip. It can record and loop playback commonly used broadcast content without requiring external storage.
5.How is the power consumption and battery life performance?
Low-power design, optimized for battery-powered portable devices, effectively extends overall battery life.
6.How to access development resources and technical support?
Please contact us to obtain datasheets, reference designs, and technical support to help you quickly complete product development.