Texas Instruments Incorporated

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GC1012B 3.3V DIGITAL TUNER

SLWS138B

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5.8

LATENCY THROUGH THE GC1012B

Two latencies are of interest, the latency from a step function in to a step function out (midpoint), and the

latency from a step function until the end of the “ringing” in the step function output (endpoint). These latencies are:

Another latency of interest is the delay from SS input to stable WS. The WS strobe becomes stable and is

low after 9 clocks, before 9 clocks the WS is unknown and may go high at any time. The delay until the first valid

high WS is a function of decimation. For decimate by 2 the delay from SS is 10 clocks, for 4 the delay is 12 clocks,

for 8 the delay is 16 clocks and for decimation ratios of 16, 32 and 64 the delay is 24 clocks. WS is high at clock 24

for all decimations.

Table 6: Latency

Output Mode

Midpoint

Endpoint

Values of D

(decimation)

Real

41 + 20D

41 + 40D

1, 2, 4, 8, 16 and 32

Complex

35 + 10D

35 + 20D

2, 4, 8, 16, 32 and 64