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TIMING CHARACTERISTICS

ADS8411

SLAS369B – APRIL 2002 – REVISED DECEMBER 2004

All specifications typical at –40

°C to 85°C, +VA = 5 V, +VBD = 3 V(1)(2)(3)

PARAMETER

MIN

TYP

MAX

UNIT

tCONV

Conversion time

340

400

ns

tACQ

Acquisition time

100

ns

tpd1

CONVST low to conversion started (BUSY high)

40

ns

tpd2

Propagation delay time, end of conversion to BUSY low

10

ns

tw1

Pulse duration, CONVST low

20

ns

tsu1

Setup time, CS low to CONVST low

0

ns

tw2

Pulse duration, CONVST high

20

ns

CONVST falling edge jitter

10

ps

tw3

Pulse duration, BUSY signal low

Min(tACQ)

ns

tw4

Pulse duration, BUSY signal high

370

ns

Hold time, first data bus transition (RD low, or CS low for read cycle,

th1

40

ns

or BYTE input changes) after CONVST low

td1

Delay time, CS low to RD low (or BUSY low to RD low)

0

ns

tsu2

Setup time, RD high to CS high

0

ns

tw5

Pulse duration, RD low

50

ns

ten

Enable time, RD low (or CS low for read cycle) to data valid

30

ns

td2

Delay time, data hold from RD high

0

ns

td3

Delay time, BYTE rising edge or falling edge to data valid

2

30

ns

tw6

Pulse duration, RD high

20

ns

tw7

Pulse duration, CS high

20

ns

Hold time, last RD (or CS for read cycle ) rising edge to CONVST

th2

50

ns

falling edge

tsu3

Setup time, BYTE transition to RD falling edge

0

ns

th3

Hold time, BYTE transition to RD falling edge

0

ns

tdis

Disable time, RD high (CS high for read cycle) to 3-stated data bus

30

ns

td5

Delay time, end of conversion to MSB data valid

20

ns

Byte transition setup time, from BYTE transition to next BYTE

tsu4

50

ns

transition

td6

Delay time, CS rising edge to BUSY falling edge

50

ns

td7

Delay time, BUSY falling edge to CS rising edge

50

ns

Setup time, from the falling edge of CONVST (used to start the valid

conversion) to the next falling edge of CONVST (when CS = 0 and

tsu(AB)

70

350

ns

CONVST used to abort) or to the next falling edge of CS (when CS is

used to abort)

Setup time, falling edge of CONVST to read valid data (MSB) from

tsu5

MAX(tCONV) + MAX(td5)

ns

current conversion

Hold time, data (MSB) from previous conversion hold valid from

th4

MIN(tCONV)

ns

falling edge of CONVST

(1)

All input signals are specified with tr = tf = 5 ns (10% to 90% of +VBD) and timed from a voltage level of (VIL + VIH)/2.

(2)

See timing diagrams.

(3)

All timings are measured with 20 pF equivalent loads on all data bits and BUSY pins.

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