Has anyone here used the AMC7150 IC to make their own drivers? I am looking for a driver with about 1.4A output to push some well-heatsinked XR-E emitters on a new thrower. It's still in the concept phase now; mostly just some doodles and brain cycles...
Anyway, after reviewing the data sheet, the AMC7150 seems like a really promising option. It's advertised as supporting input voltages from 4-40V, useful since my initial plan is to power my light from a 12V SLA battery. Based on component selection, output current up to 1.5A can be regulated. I've not looked at circuit designs for this IC closely, but it seems that it may be well suited to my application. If anyone has any experience DIYing with this component, please share your input!
In the datasheet it says: Output Voltage = -0.3V to 40V
So, it means that I can control more than one led up to 60 Watts... interesting for multiple LEDs (and multiple batteries because it will be a linear driver)
I don't mean to "rain or your parade", but I don't see anything terribly unique or exciting about this part. It is a switching type regulator (not linear), it doesn't PWM well at high frequency (I'd estimate 400Hz or less), and the 330mV sense voltage makes it a bit less efficient than other parts of this type.
But please don't give up! I see too few posts from people 'rolling their own' drivers. I for one, enjoy the reward of light blazing forth from a new driver circuit that I've wired together. That is, as long as the light is coming from the LED, not the driver board... But that's half the fun of it! Over the years I've made dozens of driver boards for different host flashlights. All of them taught me something new.
I've just started working with the ST Microelectronics ST1CC40
It has much of what I'm seeking:
3-18V, 3A led current, synchronous rectification, 100mV reference, decent PWM frequency (1000Hz). I drawback might be that the package is surface mount only. But that is to be expected nowadays, especially with the amount of power it is controlling.
I think PWM isn't a problem, you can buy an AVR chip and program is as you like (thanks to Tido's Guide), then you can insert as many AMC7150 as you need, the most common would be 2xAMC7150 for 3A I think.
Then yhe interesting part is to install something to regulate the input into a desired constant voltage; i mean, act as Boost and or Buck.
I've not used the AMC7150 yet but have been using the AMC7140 a lot.
AMC7140 either has the inductor built in or does not use one. It does max 0.7 A.
One thing to note about these AMC controllers is that your LED string forward drop has to be within about 1.5v of the power supply voltage, in order to keep the chip's power dissipation low. You can't drive a 9v string with a, say, 40v supply - your controller will go up in smoke (this is experimentally verified ;-)
Other thing I've found with the 7140 is it does not handle very noisy supply well: running a 10.8v string off 12v supply at 600mA I fumbled the alligator clip connecting V+ and "bounced" the supply on/off a bunch of time quickly... the 7140 went up in smoke.
If everything is solidly wired and power is applied in a clean manner and the LED voltage is within about 1v of supply voltage, then I've found the 7140 to be very reliable.