Other Parts Discussed in Thread: TLC5927
Hi,
I'm building a board that should control external stepper drivers that have optoisolators on their signal inputs. At 5V, these consume 13mA (a fixed resistor is already in line).
For safety reasons, I'd like to detect if the cable connection to the driver board is broken or shorted, so my idea is to use an LED driver with open/short detection there.
The product matrix shows that the TLC59281 has "fault detection", "LED open detection" and "power good", however none of this is mentioned in the datasheet, except for a connection from SDO back to the controller for error reporting in the application circuit.
Also conspicuously absent is the voltage drop, if any, in the driver IC. The equivalent circuit shows a BJT, so I'm guessing 0.7V, which would mean that I need a rail with at least 6V to drive my optoisolators.
Questions:
- Are the fault detection features omitted in the datasheet, or not implemented in the IC?
- If they are implemented, how would I get error information?
- What is the minimum voltage drop of the regulator?
Last but not least, if there is a reason why using a LED driver in this way is a stupid idea, I'm also all ears.
Simon
