DAC39RF10 datasheet(132/232 Pages) TI2

132 / 232 page

7.4.3 NCO Synchronization Latency

There are two deterministic methods for synchronizing the NCO (frequency or phase change, accumulator

reset): through an LSB of the JESD204C interface or via SYSREF. The latency parameters for each

sychronization method are listed in Table 7-41.

Using SYSREF as the Synchronization source, the latency parameter TSYSREF_NCO is the time between the

moment SYSREF is sampled high by CLK and the arrival of the NCO change at the DAC output. The alignment

to the data path samples can be calculated by the Excel spreadsheet latency calculator discussed in Section

7.4.4.

When using the JESD204C interface LSB, the latency parameter TJSYNC_NCO is the difference in time of the

NCO synchronization event relative to the corresponding data sample aligned with the LSB. TJSYNC_NCO is

deterministic, but for some modes depends on the alignment of the LSB rising edge to the multiframe boundary

(see Table 7-42).

Table 7-41. NCO Synchronization Latency Parameters

Latency Parameter

Description

Value

TSYSREF_NCO

Latency from SYSREF sampled high (by CLK) to DAC output reacting to an NCO

synchronization event (that was triggered by SYSREF).

477.5 CLK cycles

TJSYNC_NCO

The latency through the interpolation filter(s) to the NCO minus the latency of the

LSB that synchronizes the NCO. Applies only when using the LSB of the input data

to synchronize the NCO. To make input sample n be the first sample to be mixed

with a new NCO frequency or phase, the LSB should be brought high on sample n’

= n+TJSYNC_NCO/LT. Note that n’ may not be an integer as the synchronization path

is not always a whole number of input sample periods.

See Table 7-42

Table 7-42. TJSYNC_NCO vs. LT

Interpolation Factor (LT)

TJSYNC_NCO [CLK cycles](1)

-144, -142, -140, -138, -136, -134, -132, -130

-89, -86, -83, -81, -80, -78, -77, -75, -74, -72, -71, -69, -68, -66, -63, -60

-36, -32, -28, -24

34, 40, 42, 46, 48, 52, 54, 60

86, 94

186, 194, 198, 206

290

458, 466

648

968

1396

2036

128

2932

192

4212

256

6004

(1)

When multiple values are listed, it indicates that TJSYNC_NCO depends on when the LSB rises with respect to the multiframe boundary.

7.4.4 Data Path Latency

There are several difference latencies defined for the device as shown in Figure 7-57 and listed in Table 7-43.

The latency within the device is dependent on the mode of operation, including JMODE, Interpolation factor,

RBD setting, NCO usage and DES setting. An Excel spreadsheet calculator is provided by TI to calculate the

device latency in different modes of operation.

In JESD204C subclass 0 operation, the latency from Serdes input to DAC output is called TDAC_LAT0 and is not

deteriministic and a minimum and maximum range is provided in the Excel spreadsheet calculator.

DAC39RF10-SP, DAC39RF10-SEP

DAC39RFS10-SP, DAC39RFS10-SEP

SBAS932A – MARCH 2024 – REVISED FEBRUARY 2026

www.ti.com

132

Submit Document Feedback

Product Folder Links: DAC39RF10-SP DAC39RF10-SEP DAC39RFS10-SP DAC39RFS10-SEP

DAC39RF10 Datasheet(PDF) 132 Page - Texas Instruments

DAC39RF10 Datasheet(HTML) 132 Page - Texas Instruments

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

Datasheet Download

Link URL