No DC isolated power: for battery, making Blueooth headset.
It can be connected to two phones (the only way boo automatically chainback last paired phone, thepenutimate pairing the phone will need to manually connect)
With a call feature, CSR8645 low power consumption, the power is turned on,the default maximum volume.
Amp using TI TPA6 132 better sound quality
GND and BAT of 3 .7V or 4 .2V lithium battery(battery not included)
OUTL, AGND, OUTR balanced output can be directly connected to headphones, amplifiers,a udio and other inputdevices.
COM for the key public side, the other end keys are conneced VOL+,VOL- PREV,NEXT,PLY
M + and M- are connected to the positive and negative microphone.
1 x 4.1/4.0 CSR8645 Bluetooth Amplifier Board