MC34063A: Design Split Rail +-12V for HeadPhone Application, AC powered and or battery 9V.

Hi Neil,
I want to double check about the requirement.
1. there are two output rail, one is +12, and the other is -12v. both rail need 200mA output current.
2. no require ground isolation.

Hi Jasper,

Ground isolation is required. All option is in consideration. Cost is a driver though.

The client wants to use Wall Mount AC adapter such as  WAU12-200.

For the headphone amplifier, the design team selected the TI LM4562 and or LME49720, or the OPA2134.

For me the NE5532 and RC4580, with load 600OHM should be adequate. So we are looking at all options.

Since noise is an issue, ground isolation key to the design, the main driver.

Thank You,

Neil Henry

IRAD LLC

Hi Neil,
there seem be two inputs, one is from 120VAC line, one is from 9V battery. and the headphone need +-12V DC for the amplifier.
1. I would suggest select AC-DC adapter instead of AC-AC, such as SWI5-12-N-P5, lower cost and higher output power.
2. from the 12V adapter or the 9V battery, we can use TPS61170 to generate +-14V for the amplifier. the boost converter can generate 14V and adding two diodes and one cap to generate the negative 14V.

Hi Jasper,

Thank you. We will go with the part number, SWI5-12-N-P5 for the AC-DC adapter.

However, to generate +-14V for the amplifier, the.... converter generate 14V and adding two diodes and one cap to generate the negative 14V, we need a PDIP(8) package.

Kindly suggest an IC PDIP(8) package besides MC34063A if not meeting the +-14V requirements.

Regards,

Neil Henry

Hello Jasper,

I found this reference design PMP7006 for the IC MC34063A.

I would like to modify it for our objective, plus and minus 12V. Client will delete the 9V battery requirements.

Can you recommend a viable T1 for this design, since the WE 760370102 not on market. Looking for an alternative part number.

Thank you.

Neil

Hi Neil,
the reference design can only support 20mA that doesn't meet you requirement. I need to research if there is other better solution. will reply you next week.

Hi Neil,
I think we can use two MC34063A, one with boost structure to generate +14V. the other with buck-boost structure to generate -14V.
I want to avoid using transformer, which is high cost and not easy to find in the market.