TPS62400: Feed-Forward

Q: TPS62400: Feed-Forward by 574

I was looking through the TPS62400 datasheet and I saw this statement:

During PWM operation the converters use a unique fast response voltage mode controller scheme with input voltage feed-forward to achieve good line and load regulation allowing the use of small ceramic input and output capacitors.

Just wondering if this IC really has input voltage feedforward circuitry monitoring the VIN pin.  I ask because I didn’t see any connections to VIN in the block diagram.  Looking for some clarification and, if it does monitor VIN, how it’s implemented.


A: Re: TPS62400: Feed-Forward by 10449

The TPS62400 and similar ICs like the TPS62410 and TPS62420 have an internal voltage feedforward circuit that bypasses the error amp and immediately adjusts the duty cycle to account for changes in input voltage.  The details of this circuit are proprietary and can't be discussed.  The TPS62400 datasheet contains line tranisent response figures to show the end result. There is an EVM available so your customer can measure line transients with their specific operating conditions.