Mantech MH-M28 User Manual

M38
编号
引脚
说明
1
5V
5VDC
2
GND
GROUND
3
VBAT
Li BATTERY IN : 3.7-4.2V
4
L+/L-
Left channel output (direct speaker connection)
5
R+/R-
Right channel output (direct speaker connection)
1. Power supply: You can directly use the MICRO USB Android cable 5V for power supply, or you can
also connect a 5V power supply or a 3.7V lithium battery. Note that the 5V and 3.7V power supply
interfaces are different. 5V is connected to 5V and GND, and 3.7V lithium battery is connected to VBAT
and GND.
The maximum operating current is 5V2A. It is recommended to use a 5V2A regulated power supply for
better sound quality.
2. Support USB sound card, free drive (plug and play). Connect the module to the computer with a USB
data cable, the computer can play music through the module amplifier output
3. Audio output: output left and right channel stereo audio signals, can be connected to two 2-8 Euro, 3-
5W speakers, 4 Euro 5W speakers for push storage.
4. This product has its own dual 5W power amplifier circuit, it can't be connected to another power
amplifier! The output of the two power amplifiers cannot be connected in parallel or the negative poles
are connected together, otherwise the power amplifier chip will be damaged.
• Precautions
1. Signal interference: The Bluetooth antenna is extremely susceptible to high-frequency or strong
electromagnetic signal interference. Try to place it away from the sending wireless equipment. And the
board can not be next to metal objects, keep a certain distance.
1. If there is current noise from the power amplifier board, the cause is caused by ground wire
interference. It is recommended not to use plug wires at the output of the Bluetooth module. It is
necessary to solder wires, especially the ground wire, and the wire should not be too long. The shorter the
better , Try to be thicker. The problem that the audio ground is at the ground point of the power amplifier
board must be connected to the ground of the audio input terminal of the power amplifier. This ground
point can be tried to be soldered at different positions to achieve the lowest current sound. It is
recommended that the Bluetooth and the power amplifier board be powered separately to isolate the
Bluetooth ground and the power amplifier ground.
1. As this product is a bare board design, try not to touch the components on the board with your hands, it
is easy to cause static electricity to kill the chip and cause burnout.
Warning: The charging interface of this product is current limiting charging mode, without charging
management! For the safety of your life and property, please be sure to use a lithium battery with a
protective plate produced by a regular manufacturer. If the loss is caused by improper use, our company
will not bear any responsibility!
Another: When using MH-M18, please pay attention to the following two points:
Power supply: 5V power supply is used by default. If you need to use 3.7V lithium battery power supply,
you need to replace the diode with 0603 0 ohm resistor, or directly short circuit the two ends of the pad.

Mantech MH-M28 Specifications

General

Brand	Mantech
Model	MH-M28
Category	Control Unit
Language	English