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DAC7573

SLAS398 – SEPTEMBER 2003

Table 2. Control Byte

C7

C6

C5

C4

C3

C2

C1

C0

MSB7

MSB6

MSB5...

Don’t

MSB

MSB-1

MSB-2

A3

A2

Load1

Load0

Ch Sel 1

Ch Sel 0

PD0

Care

(PD1)

(PD2)

...LSB

DESCRIPTION

(Address

Select)

(A3 and A2

0

0

X

0

0

0

Data

Write to temporary

should corre-

register A (TRA) with

spond to the

data

package ad-

Write to temporary

dress, set via

0

0

X

0

1

0

Data

register B (TRB) with

pins A3 and

data

A2)

Write to temporary

0

0

X

1

0

0

Data

register C (TRC) with

data

Write to temporary

0

0

X

1

1

0

Data

register D (TRD) with

data

(00, 01, 10, or 11)

Write to TRx (selected

by C2 &C1

0

0

X

1

see Table 8

0

w/Powerdown Com-

mand

(00, 01, 10, or 11)

Write to TRx (selected

0

1

X

0

Data

by C2 &C1 and load

DACx w/data

(00, 01, 10, or 11)

Power-down DACx

0

1

X

1

see Table 8

0

(selected by C2 and

C1)

(00, 01, 10, or 11)

Write to TRx (selected

1

0

X

0

Data

by C2 &C1 w/ data and

load all DACs

(00, 01, 10, or 11)

Power-down DACx

1

0

X

1

see Table 8

0

(selected by C2 and

C1) & load all DACs

BROADCAST MODES (CONTROLS UP TO 4 DEVICES ON A SINGLE SERIAL BUS)

Update all DACs, all

X

X

1

1

X

0

X

X

X

devices with previously

stored TRx data

Update all DACs, all

X

X

1

1

X

1

X

0

Data

devices with MSB[7:0]

and LSB[7:0] data

Power-down all DACs,

X

X

1

1

X

1

X

1

see Table 8

0

all devices

Most Significant Byte

Most Significant Byte MSB[7:0] consists of eight most significant bits of 12-bit unsigned binary D/A conversion

data. C0=1, MSB[7], MSB[6] indicate a powerdown operation as shown in Table 8.

Least Significant Byte

Least Significant Byte LSB[7:0] consists of the 4 least significant bits of the 12-bit unsigned binary D/A

conversion data, followed by 4 don’t care bits. DAC7573 updates at the falling edge of the acknowledge signal

that follows the LSB[0] bit.

Default Readback Condition

If the user initiates a readback of a specified channel without first writing data to that specified channel, the

default readback is all zeros, since the readback register is initialized to 0 during the power on reset phase.

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