About latency if we do not use each internal blocks (PREMOD, HB1, HB2, HB3, NCO and IQ Modulation)

Question

Hi, 
 Our customer is considering to operate AD9148 without using internal function blocks. 
 As the title, how long time delay (= latency) does AD9148 be bypassed each function blocks? 
 In the datasheet, it has the latency of using function but it does not have value when do not use function. 
 - Latency of bypassing PREMOD: ?? 
 - Latency of bypassing HB1, 2 and 3: ?? 
 - Latency of bypassing NCO: ?? 
 - Latency of bypassing IQ Modulation: ?? 
 
 Best Regards, 
 Kakehi

PMH2023 · Accepted Answer

Hello, With regard to latency specification, it would appear that latency is per function. Note, the inclusion of course modulation does NOT add to latency due to the manner in which it is implemented (i.e. modify filter coefficient polarity vs actual NCO). The fine NCO is implemented with multipliers hence the added 12 cycles. Also, the pre-mod function does not add to latency since this does not require digital multipliers since data polarity is only being affected (i.e.multiply by +1 or -1). With regard to your example which pertains only to 1x (bypass) mode...........latency is 64 cycles. If you were to operate in 8x interpolation mode (no inv Sinc or fine mod).............the latency would be 951 cycles (=64+125+254+508) regardless if course modulation via filter was enabled or not.)

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About latency if we do not use each internal blocks (PREMOD, HB1, HB2, HB3, NCO and IQ Modulation)