Bridged chip amp to current drive

[Freedom666]

Hello, who knows to model in Spice a schematic for a bridged current drive amp?

For example for a TDA2003 amp?

Schematics here and proposition how to do it from Esa Merilainen.

https://www.diyaudio.com/community/...fication-to-current-drive.389985/post-7253904

It's possible, so why not try out?

It would be great to see it. I would try it out (build one) if I would know which parts are needed. And give feedback.

 

[HAYK]

This is much simpler current bridge with 2A/V. You have Tina model to play around.
The input can be balanced.

 

[HAYK]

It is 4A/V and R11 should be adjusted to get both outputs equal.
R6=>R4
R3=>R5

 

[Freedom666]

Thank you Hayk.

However I would have to make a parts list as I am not sure if I read everything correct.

Is there a better readable schematic? I am not into electronics and need to understand every detail like applied voltage, input, output and so on

 

[HAYK]

You asked a model in spice. This is not a tried out circuit, it is a quick designed to show the feasibility. The distortion values might be relatively high. If you use the Chinese TDA2050, $1.5 for 10units, you can get better result as these chips are stable with unity gain, so lower distortion for the inverter and do not need output RC to be stable. You can make it single supply by creating Vcc/2 to replace the grounds and add input capacitor. The output inductor is optional for stability.
This vendor sells per unit and I got the best quality not what shown with thick leads. The LM1875 are cheaper $1/10u, inside are the same chips but slightly less open loop gain.
https://www.aliexpress.com/item/400...order_list.order_list_main.268.21ef1802AW3FLd

 

[Freedom666]

Oh, I thought that with simulation in Spice you get already usable results.

The same schematic works for TDA2050?

Interesting. Maybe spice can put out some better readable schematic?

If I find time I will draw a schematic. Will see.

 

[tomchr]

You're probably aware already, but beware that with a BTL amp, each amp half sees half the load impedance. So make sure you select chip amps (and supply voltages) suitable for 2 Ω operation if the lowest supported load by the complete amp is 4 Ω.

Tom

 

[Freedom666]

OK, I see.

I would like to know how to transform the TDA2003 bridged amp into a current driven amp.

This one would support 4 ohm operation in BTL mode as it can stand 1.6 ohms as a single chip.

 

[Freedom666]

I see here they discussed how the resistors have to be dimensioned.


https://www.diyaudio.com/community/threads/current-drive-for-loudspeakers.250272/post-7315742

 

[tomchr]

You might be able to get some ideas from the MyRef thread.

Tom