Error signal to PWM Converter

Samuel Jaffe

Other Parts Discussed in Thread: UC3823B, UC3825B, UC3823A, UC3825, UC3823, UC3825A

Hi E2E,

I apologize in advance for probably posting this in the wrong group. I figured we have this system inside these parts so you would have the best idea for a solution.

My customer is looking for a single-chip solution that takes two analog signals (0V - 4.5V) and generates an error signal represented by a PWM signal (>500KHz). He also wants access to the reference voltage on the error amplifier. It doesn't matter if it's current mode or voltage mode.

Do we have a single-chip solution that fits these specs?

Other info:

Vsupply available are 3.3V, 5V, 15V
Sinplest solution, single-chip preferred
Output of PWM will drive a logic gate. Very little power needed.
Cost is the priority

Thanks,

-Sam

over 8 years ago

0 Brian Johnson96 over 8 years ago

TI__Expert 3200 points

Hi Sam,

Possibly the UC3823A, UC3823B, UC3825A, UC3825B, UC3823, or UC3825 family of PWM controllers could be considerations depending on how the error signal is created from the two analog inputs since in these controller families both the inverting and non-inverting inputs of the error amp are accessible as well as the ramp input to the PWM comparator has some room to access the reference voltage. The output stage is going to be stronger then required.

0 Samuel Jaffe over 8 years ago in reply to Brian Johnson96

TI__Mastermind 25590 points

Brian,

Thank you for your reply. These look like the right parts for the job.

Thanks again!
-Sam

Power management

Power management forum

Error signal to PWM Converter