There are many instances where a very simple to build (and relatively cheap) power amplifier is needed. The TDA2030 is a single chip amplifier capable of 14W output into 4 ohms with a few external components.
It can be used for almost any application you could think of. The power from this amplifier is very average of many amplifiers, which means it could find applications anywhere, here are just a few ideas:
- A pair can form a capable amp for a stereo system (i.e. a home made or upgraded midi system or 'ghetto-Blaster', although battery operation will not be possible).
- This amplifier can be used to complete surround sound systems (i.e. centre and rear channel amps). I used this amp for my centre channel in my original surround sound system. It now lays unused, waiting for a mono audio application to present itself.
- A pair can be used to improve the sound from a NICAM® TV, or even one may be used to improve a mono TV.
- Beefing up those 400W+ amps in PC speakers (seriously)!
- Tweeter or mid range amplifiers in bi-amp or tri-amp systems.
UPDATE: Missed the diodes when producing the schematic - they are in there now and its all accurate.
This amplifier is based on the typical application in the ST Microelectronics datasheet. The performance from this circuit is very satisfactory. The sheet contains data for typical noise and distortion statistics, I cannot confirm these statistics because I don't have the equipment, but my ears tell me that the sound is good and with sensitive speakers, this amp will show some power.
As can be seen, the circuit is quite simple indeed. If you can make your own PCB's (even in freehand style like me), the circuit is very simple to make and you can design the PCB to accept the odd, staggered pin-outs of some TO220 devices. Wiring this amp onto veroboard or stripboard is possible, but a real pain because the pins do not naturally fit the standard holes on these boards. I have wired a TDA2040 (similar amp) onto stripboard with success, but I had to bend the pins straight first, then cut them to them same length followed by carefully spreading them out. A diagram is below:
The contains ST Microelectronics datasheet a diagram of a possible PCB layout you might want to use. I have done so when I built my TDA2030 amp and it is very well suited to the chip and a standard range of components. The only adjustments I made were to move holes so they were optimal for my components obtained.
Note: The above image is copied directly from the datasheet and is not mine, nor is it likely to be 1:1 scale. To achieve this scale, the best idea is to print to PDF file to A4 paper.
Resistors should be at least 1/4W types with 1% tolerance recommended. I used 0.6W 1% metal film resistors and they work well. Capacitors I used were electrolytic cans for C2, C5 and C6. At the time of building, I did not have enough 100uF caps so I used 220uF caps instead, this will not cause trouble, unless you use caps that are smaller than 100uF for C5 and C6.
C1 can be electrolytic, I used a tantalum myself (don't ask why, since they are actually more expensive). Some readers may want to use a polyester capacitor for the input (C1), this would work too but I am not sure whether any benefit will arise from the extra expense. Other capacitors (bypass caps C3 and C4. and C7) are ideally polyester caps. Mylar may be used but I prefer polyester caps and they are not expensive unless you get large values.
The values of R5 and C8 are worked out from the equations in the datasheet, but I used 1.8k ohm for R5 and 220pF for C8 and they work fine. Diodes should be 1N4001 or similar (make sure you solder them in the right way round).
A good heatsink is important and this should be a large size with good thermal conductivity. When you operate the TDA2030 from the (recommended) split rail power supply, you must insulate the device from the heatsink using a mica washer or similar. With single rail supply, this is not needed.
Before wiring I must mention this VERY important statement. I do not like ignorant and therefore potential dead readers!<>THE POWER SUPPLY REQUIRES MAINS VOLTAGE WIRING. DO NOT WIRE IT UNLESS YOU ARE SUITABLE QUALIFIED, DEATH OR SERIOUS INJURY MAY RESULT.
The supply voltage for this amp is a maximum of +/- 18V. You can obtain +/-17V using a suitably regulated 12V transformer, which should be 40VA or more for one amp. Increase this to 80VA for two amps.
4700uF capacitors at 35V (16V caps is pushing the boundaries a bit) should be fine for an amp like this, but feel free to increase (not decrease) this, however benefits are minimal and the good old law of diminishing returns will set in. A fuse must be installed too and the supply must be properly earthed.
The datasheet also shows an application for a bridge version of the amplifier. This has an output of 28W into 4 ohm loads with a supply of +/-14V.
I have not built this version yet so I cannot make any guarantees of its performance, but it is likely to please for the cost. There is also no PCB layout supplied in the datasheet so you will need to design your own.
I can say a few things though. When using the bridge version, loads smaller than 4 ohms should not be used and the speaker must not be shorted to ground either.
With the bridge version, the VA rating of the transformer must be doubled. This means 80VA for one bridged amp, 160VA for two.
My first (and only) TDA2030 amp has satisfied me for its application for a centre channel amplifier in my old surround sound system. While now unused, it is ready to return to life whenever I need it to.
The sound is very appreciable, it is unlikely to be hi-fi but will certainly out-perform most commercial offerings at the same price. It also includes short circuit protection, power limiting to protect the output transistors and thermal shut down.
I am sure you will find the right application for this amp. If you need more power, check out the article for the TDA2040.
A recommended TDA2030 project
Whilst looking through Mark Hennessy's website, I found he also has made a very good implementation using this popular amplifier chip.
What is even better is he has also provided complete schematics to add a tone control, high pass filter (ideal for pushing more power into smaller speakers which do not reproduce low frequencies). He has also provided a clipping detector so you know when you are pushing the TDA2030 to its limits.
For more details, see here.
I did have an implementation of my own of a stereo TDA2030 amplifier I wanted to put some pictures and details up of, and it served me a whole year at uni as a PC sound system, which sounded very good with a pair of cheap Ariston speakers.
I did want it to look a little more pretty before I put details on here though, and never got round to that! Now I have had the time to, it has been taken by my Dad to his work place in London so I might not see it again for some time :|
If you want less power (and cost), the TDA2006 (datasheet here) will directly replace the TDA2030 and will use exactly the same circuit above (except for the bridge one). The idea for this chip is that is just under two thirds the price and is great if you do not need the extra power. If you do use this chip, supply voltage should be around +/- 12V (9V transformer) and you'll get around 8W into 4 ohms (at a guess).