About the difference between NAX9812L and MAX9812H:
1: The operating voltage range is different (MAX9812L power supply is 2.7V-3.6V, MAX9812H power supply is 4.5V-5.5). 2: The microphone bias voltage is different (MAX9812L is about 2.2v, MAX9812H is about 4v).
From the point of view of operating voltage, the power supply range of MAX9812L and MAX9812H is very narrow, and the use is limited. We have made an expansion to deal with this problem --- externally add voltage regulator chip to supply power to MAX9812, which makes the power supply range wider (3V-12V) . Microphone bias: Most electret microphones on the market are in the range of 1.5V-10V, so no matter it is MAX9812L or MAX9812H, it can be applied without any difference.
Electret microphone input: It can be input with a 3.5 earphone plug, or externally welded (two microphones can be connected). Power input: if it is powered by a 3V battery, it can be input from the -3V-DC-IN position (note: the voltage at this position should not exceed 3.3V or the chip will be damaged), if an external power supply is used, it can be input from the 4-12V-DC-IN position ( This position can input 3.6-12V DC voltage)
Specification
Electret Microphone amplifier board
Uses electret chip MAX9812, can match any amplifier
Cable
2p power cord one, 3p (200mm long) with a shielded audio output line
