60 led-strips driver

I want to drive 60 monochromatic led strips (5w each).
A starting point would be using 74HC595 shift registers to control 72 mosfets.
I found this board http://www.elcojacobs.com/using-shiftpwm-to-control-led-strips-with-arduino/ to do exactly this with tree of them.
But anybody knows if there are IC's that could do the same ?

The Texas Instruments TLC5940 chip will do 12-bit PWM on 16 current-controlled outputs:

It can sink up to 17V (0-120 mA) so you can put a bunch of LEDs in series. Four of them will give you 64 channels.

The LED strips are typically 3 LEDs in series with a current limit resistor designed to run from 12V - a long strip will have many 3-LED segments in parallel, with each segment needing ~ 20mA. Plan accordingly.

johnwasser:
The Texas Instruments TLC5940 chip will do 12-bit PWM on 16 current-controlled outputs:

True, but it's a current sink so it makes driving MOSFETs much more complex than it needs to be.

Lucamarkio:
I want to drive 60 monochromatic led strips (5w each).

But anybody knows if there are IC's that could do the same ?

I'm guessing they're 12V strips.

5W means 0.416 amps per strip, that's 60 LEDs.

I don't think there's an IC that can do half an amp on each pin... you'll need the MOSFETs.

Yup - even tpic6a595 only does 350mA continuous.

tpic6a595.pdf (575 KB)

Johnwasser,
your solution seems nice, I'm looking at the datasheet and I see I can connect multiple ICs in series,
however 120mA is not enough since I need to power one 5w led strip on each IC output. As fungus said that would be 416mA on each pin( and I need 60 of them)

350mA is too risky for my application.
If there's no ICs for that I should definitely go with a board like the one in my first post ( 74HC595 + MOSFETS ) . Unfortunately that board is not available, do some of you can help providing or finding something similar and readily available?

Lucamarkio:
Johnwasser,
your solution seems nice, I'm looking at the datasheet and I see I can connect multiple ICs in series,
however 120mA is not enough since I need to power one 5w led strip on each IC output. As fungus said that would be 416mA on each pin( and I need 60 of them)

How are the LEDs in the 'strip' wired? How many LEDs? Voltage drop across each? Current limiting resistors? Supply voltage?

To drive MOSFETs with the TLC5940's open-collector outputs can't you just add a pull-up resistor to each Gate?

johnwasser:
How are the LEDs in the 'strip' wired? How many LEDs? Voltage drop across each? Current limiting resistors? Supply voltage?

LED in the strip are wired exactly as CrossRoads explained.
Im dealing with 100cm pieces of these strips http://www.entityel.com/datasheets/1300ENSTRIP5-120.pdf ( 60 of them)

johnwasser:
To drive MOSFETs with the TLC5940's open-collector outputs can't you just add a pull-up resistor to each Gate?

If I were to manually solder 60 mosfet I would go with eight 74HC595 ( like the board linked in my firs post ).
I'd like to find an IC that saves me some time

This is the work i’ve done last summer… and that I want to avoid redoing with 3 times the outputs

back view

Lucamarkio:
I’m dealing with 100cm pieces of these strips http://www.entityel.com/datasheets/1300ENSTRIP5-120.pdf ( 60 of them)

If a full 5M strip draws <=48W@12V that’s <=4A. Each of the 200 3-LED segments (2.5cm) draws 20 mA. Your 100 cm (1 M) segments should draw 800 mA (9.6W @ 12V).

What made you think your strips were 5W?

Looks like you're ready for a PCB. How soon do you need this?

johnwasser:
If a full 5M strip draws <=48W@12V that’s <=4A. Each of the 200 3-LED segments (2.5cm) draws 20 mA. Your 100 cm (1 M) segments should draw 800 mA (9.6W @ 12V).

What made you think your strips were 5W?

You’re right :cold_sweat:
I need to verify this thing. Either they gave me the wrong datasheet or they told me b******t. The right datasheet is probably http://www.entityel.com/datasheets/1300ENSTRIP5.pdf

CrossRoads:
Looks like you’re ready for a PCB. How soon do you need this?

ASAP, I’d say yesterday!

That’s not very good planning then 8)
The picture you posted, that’s just daisychained 74HC595s driving N-channel MOSFETs with 2-screw terminal per strip, one the MOSFET open drain and the other +12V?

CrossRoads:
That's not very good planning then 8)
The picture you posted, that's just daisychained 74HC595s driving N-channel MOSFETs with 2-screw terminal per strip, one the MOSFET open drain and the other +12V?

Exactly!
The picture lacks a power plug but basically in the first picture on the left you can see two long leads crossing, that's the power input .

It's quite a generic circuit, also the board i posted at the beginning of this thread is almost identical. How is it possible I cannot find a similar board in production?

With 60 drivers? I expect it would be somewhat unique.

What about an 8 output module ? I could combine them to make 8x8 = 64 outputs.

So maybe 2 boards like this, daisy chained together.

32MOSFETdriver_layout.png