LTC6992 adjustable frequency while running?

Question

I see that the output frequency can be set using Rset in the datasheet, but the specific words are "Rset programs the LTC6992's internal oscillator frequency" Does this allow for the frequency to be tuned while running i.e. or adjusted on the fly? Or rather just set and maintained during startup of this chip? 
 I am hoping to use this chip in a scenario where frequency adjustment would be beneficial, and hope that a variable Rset (well within the datasheet's provided range) could achieve this operation. 
 To add to this same topic, could Ndiv be changed/modified during operation as well? (Given the correct external circuitry of course) 
 
 Thanks for your help! 
 SbeTav

ADIApproved · Accepted Answer

The short answer is that both frequency changes by the SET pin and divide changes are both available with the LTC6992-X parts. The divider changing is described on the data sheet on page 19. To change frequency by the SET pin the procedure is the same as described on the LTC6990 data sheet on pages 16-20. In both cases the changes are not instant and there are settling issues as described on the data sheets. If only a couple of frequencies are required, different Rset resistors can also be switched in.

Electronic Design Services - PartnerZone

LTC6992 adjustable frequency while running?

Top Replies