Hi All,
>
> I need to produce 4 PWM signals to input to 4 power MOSFETs that are
> driving 4 DC motors. The MOSFET side of things is done/tested/working.
> Currently I'm producing the PWM signals with a computer I/O interface,
> however since I'm going with an embedded solution I want to give the
> PWM generation to the hardware to take some burden off of the embedded
> controller as it has other things to do.
>
> I've looked at ICs like the Tl494 or the UC1824 for PWM generation,
> but I'm not sure they are the best for motor control, and I've had a
> really hard time finding some simple application notes on these 2 ICs.
> Basically, I'm looking for a single IC solution that will allow me to
> give 4 analog signals to the chip and will produce 4 unique PWM
> signals with minimal external components. The PWM frequency is
> flexible.
>
> If a 4 channel Voltage-to-PWM IC is not available can anyone suggest
> the simplest single channel Voltage-to-PWM IC that will require
> minimal components for my application?
>
> If anyone has any suggestions, please let me know.
>
> Thanks,
> wind-it-up
>
Look at the Atmel AVR microcontrollers -- they have versions with up to 3 PWM outputs, and most all of them have A/D converters with 8 channel multiplexed inputs.... or just use 4 of them -- I've used the Atmega168 for PWM motor control and it had plenty of horepower for dealing with encoder inputs, PWM generation, and a serial configuration interface... it comes in an 18 pin dip and other packacging and is more than up to the single channel task with minimal programming... there are probably 8 pin atmel or pic controllers that can do the job if you want to hold down board space :)
RE: minimal components -- the Atmega168 has onboard system clock (1mhz if I recall correctly.... external crystal up to 20mhz optional) so about the only external components needed are power-on-reset and power supply filtering, plus anything your specific application requires.