TIP35/36C maximum power at one pair

[davidsrsb]

FWIW smaller and cheaper TIP142/147 have in practice same or better SOA, go figure, so *they* became an Industry standard.

Interestingly the Onsemi TIP142 hits 1A@60V, ST have a basic graph in their TIP142 datasheet and its about 1A@48V, so a much inferior part -makes you wonder about their TIP35

 

[rezapile]

im building car amp with tip35c/tip36c how much power supply for 3pair tip35c/tip36c for 2 ohm load

 

[AndrewT]

the tip35 is spefyfied @ 125W
3pairs adds up to total Pmax of 750W
Maximum output power if you can keep them warm (choose heatsink for not hot) will be 150W per channel.

 

[rezapile]

the tip35 is spefyfied @ 125W
3pairs adds up to total Pmax of 750W
Maximum output power if you can keep them warm (choose heatsink for not hot) will be 150W per channel.

thank you for help .how much vcc for 150w rl 2ohm

 

[elektryk]

Hi.

I've been doing some measurements with amp based on two pairs of ST TIP35C/36C, testing conditions are below:

-no load supply voltage: 54V
-output voltage: 23V
-supply voltage at load: 46V
-load resistance about: 2-3Ohm (it depends of heater temperature)

The test was lasting 2 minutes because heater began to stink...

Next measurements will be made with better load, for now we can see that 2 pairs should be adequate for the same supply at 4Ohm load.

 

[AndrewT]

thank you for help .how much vcc for 150w rl 2ohm

I'd guess at ~10Vdc above the output peak voltage.
150W into 2r0 requires an output peak voltage of sqrt(150W*2ohms*2) = 24.5Vpk
i.e. ~±35Vdc should get close to your target.

 

[AndrewT]

Hi.

I've been doing some measurements with amp based on two pairs of ST TIP35C/36C, testing conditions are below:

-no load supply voltage: 54V
-output voltage: 23V
-supply voltage at load: 46V
-load resistance about: 2-3Ohm (it depends of heater temperature)

The test was lasting 2 minutes because heater began to stink...

Next measurements will be made with better load, for now we can see that 2 pairs should be adequate for the same supply at 4Ohm load.

tests into lower loads for longer times become a heatsink test. They simply tell you the heatsink is big enough, or not, for continuous full power testing.

That is not what we need to know.

 

[davidsrsb]

I'd guess at ~10Vdc above the output peak voltage.
150W into 2r0 requires an output peak voltage of sqrt(150W*2ohms*2) = 24.5Vpk
i.e. should get close to your target.

ie 12A peak. Shared across three pairs is 4A peak each. The SOA curve is about 3A at 35V. This means these transistors can drive 2R MINIMUM. If you mean 2R nominal, I would aim for 100W as these transistors are much happier with ±25Vdc.

 

[AndrewT]

ie 12A peak. Shared across three pairs is 4A peak each. The SOA curve is about 3A at 35V. This means these transistors can drive 2R MINIMUM. If you mean 2R nominal, I would aim for 100W as these transistors are much happier with ±25Vdc.

?

have you carried out, at great expense to your time, a temperature de-rated SOAR for reactive loading for these transistors?

 

[davidsrsb]

?

have you carried out, at great expense to your time, a temperature de-rated SOAR for reactive loading for these transistors?

Not nearly enough information in the Onsemi datasheet for that and none from ST at all.
I see that Onsemi show about 5A dc at 25V room temperature, so based on little more than experience, I would expect that to be OK for a 3 pairs driving 100W into a 2R nominal reactive load. You may be able to get 150W or use 2 pairs, but this depends on good current sharing and keeping the temperature down. As this is a car audio application, that last bit is dubious

 

[elektryk]

tests into lower loads for longer times become a heatsink test. They simply tell you the heatsink is big enough, or not, for continuous full power testing.

That is not what we need to know.

Could you recommend better loudspeaker equivalent circuit?

 

[wg_ski]

3 pairs of TIP35/6, +/-34V regulated, 200 WPC at 2R. Perfectly reliable bridged into a 4 ohm sub. Lanzar Vibe251, still running today. Only recently replaced (two of them) with a low-heat class D. Their 100W/ch version uses one pair on +/24V, but they may be TIP3055's.