DAC8554IPW datasheet(16/34 Pages) TI2

16 / 34 page

www.ti.com

DAC8554

SLAS431B – JUNE 2005 – REVISED OCTOBER 2006

The DAC8554 also supports a number of different

Power-down/data selection is as follows:

load

commands.

The

load

commands

include

DB16 is a power-down flag. If this flag is set, then

broadcast commands to address all the DAC8554s

DB15 and DB14 select one of the four power-down

on an SPI bus. The load commands can be

modes of the device as described in Table 1. If DB16

summarized as follows:

= 1, DB15 and DB14 no longer represent the two

DB21 = 0 and DB20 = 0: Single-channel store.

MSBs of data, but represent a power-down condition

The temporary register (data buffer) corresponding to

described in Table 1. Similar to data, power-down

a DAC selected by DB18 and DB17 is updated with

conditions can be stored at the temporary registers

the contents of SR data (or power-down).

of each DAC. It is possible to update DACs

simultaneously either with data, power-down, or a

DB21 = 0 and DB20 = 1: Single-channel update.

combination of both.

The

temporary

and

DAC

corresponding to a DAC selected by DB18 and DB17

Refer to Table 2 for more information.

are updated with the contents of SR data (or

power-down).

Table 1. DAC8554 Power-Down Modes

PD0

PD1

PD2

DB21 = 1 and DB20 = 0: Simultaneous update. A

(DB16)

(DB15)

(DB14)

OPERATING MODE

channel selected by DB18 and DB17 gets updated

Output high impedance

with the SR data, and simultaneously, all the other

channels get updated with previous stored data (or

Output typically 1k

Ω to GND

power-down) from temporary registers.

Output typically 100k

Ω to GND

Output high impedance

DB21 = 1 and DB20 = 1: Broadcast update. All the

DAC8554s on the SPI bus respond, regardless of

address matching. If DB18 = 0, then SR data gets

ignored, all channels from all DAC8554s get updated

with previously stored data (or power-down). If DB18

= 1, then SR data (or power-down) updates all

channels of all DAC8554s in the system. This

broadcast update feature allows the simultaneous

update of up to 16 channels.

Table 2. Control Matrix

DB23

DB22

DB21

DB20

DB19

DB18

DB17

DB16

DB15

DB14

DB13-DB0

Don't

LD 1

LD 0

Care

DAC Sel 1

DAC Sel 0

PD0

MSB

MSB-1

MSB-2...LSB

(Address Select)

DESCRIPTION

0/1

This address selects 1 of 4 possible devices on a

single SPI data bus based on each device's address

See Below

pin(s) state.

Data

Write to buffer A with data

Data

Write to buffer B with data

Data

Write to buffer C with data

Data

Write to buffer D with data

Write to buffer (selected by DB17 and DB18) with

(00, 01, 10, or 11)

See Table 1

power-down command

A0 and A1 should

correspond to the

Write to buffer with data and load DAC (selected by

(00, 01, 10, or 11)

Data

package address

DB17 and DB18)

set via pins 13

Write to buffer with power-down command and load

and 14.

(00, 01, 10, or 11)

See Table 1

DAC (selected by DB17 and DB18)

Write to buffer with data (selected by DB17 and DB18)

(00, 01, 10, or 11)

Data

and then load all DACs simultaneously from their

corresponding buffers.

Write to buffer with power-down command (selected by

(00, 01, 10, or 11)

See Table 1

DB17 and DB18) and then load all DACs

simultaneously from their corresponding buffers.

Broadcast Modes

Simultaneously update all channels of all DAC8554

devices in the system with data stored in each

channels temporary register.

Data

Write to all devices and load all DACs with SR data

Write to all devices and load all DACs with

See Table 1

power-down command in SR.

Submit Documentation Feedback

DAC8554IPW Datasheet(PDF) 16 Page - Texas Instruments

DAC8554IPW Datasheet(HTML) 16 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