MC34063A: what Vout range we can use mc34063A to design?

Hi Michael,

the MC34063A can't support such high output power.

I would suggest a TPS61175 to generate 36V 0.2A. 

about the -36V rail, it would need a buck converter. or just use a coupling inductor with the TPS61175 to generate -31V if acceptable

Hi Sir

we can't generator 36V/0.2A wiith TPS61175, May you pls help?

                                 Bogey

Hi Jasper,

I used vin= 5v,Rsc=0.3Ohm,R1=1K,R2=11K.

Vout is correct -15V.

My question is why pin5 voltage -13.71V. Is this correct?

Its Quiescent Current 5v*50mA=250mW.

Hi Jasper,

But the Quiescent Current too great.

3 difference negative voltage's Quiescent Current over 450 mA.

Do you know how to reduce that?

Do you know what the 1.25-V Reference Regulator 's power source? 

Hi Micheal,

the Iq does large. could you measure the thermal of the power components? we need to know which one is the most power loss to find the root cause.

Hi Jasper,

The thermal come from MC34063.

Hi Jasper,

Do you have an idea about reducing the quiescent current?

The greater the negative voltage, the larger the current.