DDC112YSLASH2K datasheet(22/34 Pages) TI

22 / 34 page

DDC112

SBAS085B

www.ti.com

RETRIEVAL

BEFORE CONV TOGGLES

(CONTINUOUS MODE)

This is the most straightforward method. Data retrieval be-

gins soon after DVALID goes LOW and finishes before

CONV toggles, see Figure 24. For best performance, data

retrieval must stop t28 before CONV toggles. This method is

the most appropriate for longer integration times. The maxi-

mum time available for readback is TINT – t27 – t28.

For DCLK and CLK = 10MHz, the maximum number of

DDC112s that can be daisy-chained together is:

INT

DCLK

–

431 2

Where

DCLK is the period of the data clock. For example, if

TINT = 1000µs and DCLK = 10MHz, the maximum number of

DDC112s is:

1000

431 2

40 100

142 2

142

112

µµ =→

DDC

–

()(

)

RETRIEVAL

AFTER CONV TOGGLES

(CONTINUOUS MODE)

For shorter integration times, more time is available if data

retrieval begins after CONV toggles and ends before the new

data is ready. Data retrieval must wait t29 after CONV toggles

before beginning. Figure 25 shows an example of this. The

maximum time available for retrieval is t27 – t29 – t26

(421.2

µs – 10µs – 2µs for CLK = 10MHz), regardless of T

INT.

The maximum number of DDC112s that can be daisy-

chained together is:

409 2

µs

DCLK

For DCLK = 10MHz, the maximum number of DDC112s is

102.

FIGURE 23. Timing Diagram When Using the DIN Function of the DDC112.

Output Disabled

Output Enabled

Output Disabled

CLK

DVALID

DXMIT

DCLK(1)

DIN

Input A

Bit 1

Input E

Bit 20

Input F

Bit 1

Input F

Bit 20

MSB

Output Disabled

Output Enabled

LSB

Output Disabled

MSB

DOUT

NOTE: (1) Disable DCLK (preferably LOW) when DXMIT is HIGH.

22A, t22B

TABLE X. Timing for the DDC112 Data Retrieval Using DIN.

CLK = 10MHz

CLK = 15MHz

SYMBOL

DESCRIPTION

MIN

TYP

MAX

MIN

TYP

MAX

UNITS

t24

Set-Up Time From DIN to Rising Edge of DCLK

t25

Hold Time For DIN After Rising Edge of DCLK

t26

Hold Time for DXMIT HIGH Before Falling

1.33

µs

Edge of DVALID

DDC112Y/2K Datasheet(PDF) 22 Page - Texas Instruments

DDC112Y/2K Datasheet(HTML) 22 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

Datasheet Download

Link URL