I'm building a robotics project where I need to control a lot of DC motors. I picked the DRV8870DDAR H-bridge motor driver chip which needs 2 PWM input signals to control the speed and direction. Since I need a lot of PWM signals, I'm thinking of driving them with a TLC59116IPWR LED driver.
Unfortunately all LED drivers I found are built to sink constant current. To turn it into a digital signal I've added a 10K pull-up resistor to the signal line. Switching the "LED" on should then sink 0.5mA (at 5V) current from the resistor and output a LOW value. See the schematic below; the PWM0A line leads to the motor drivers:
- My question is whether this will work fine?
- If not, is there any alternative I should look for?
My worry is that the 0.5mA current I need to sink to output a LOW signal is too low for the chip to work. In the recommended section it mentions 5mA minimum output current, but that seems to be the lowest constant current target I can set via the REXT resistor. I don't know how the internals of the chip works, so I'm unsure if that's a problem.