DAC7565 Datasheet, PDF (28/46 Pages) Texas Instruments – 12-Bit, Quad Channel, Ultra-Low Glitch, Voltage Output DIGITAL-TO-ANALOG CONVERTER with 2.5V, 2ppm/°C Internal Reference

DAC7565
SBAS412A – FEBRUARY 2008 – REVISED MARCH 2008 ............................................................................................................................................... www.ti.com
LD1 (DB21) and LD0 (DB20) control the loading of
each analog output with the specified 12-bit data
value or power-down command. Bit DB19 must
always be '0'. The DAC channel select bits (DB18,
DB17) control the destination of the data (or
power-down command) from DAC A through DAC D.
The final control bit, PD0 (DB16), selects the
power-down mode of the DAC7565 channels as well
as the power-down mode of the internal reference.
The DAC7565 supports a number of different load
commands. The load commands include broadcast
commands to address all the DAC7565s on an SPI
bus. The load commands are summarized as follows:
DB21 = 0 and DB20 = 0: Single-channel store. The
data buffer corresponding to a DAC selected by
DB18 and DB17 updates with the contents of SR
data (or power-down).
DB21 = 0 and DB20 = 1: Single-channel update.
The data buffer and DAC register corresponding to a
DAC selected by DB18 and DB17 update with the
contents of SR data (or power-down).
DB21 = 1 and DB20 = 0: Simultaneous update. A
channel selected by DB18 and DB17 updates with
the SR data; simultaneously, all the other channels
update with previously stored data (or power-down)
from data buffers.
DB21 = 1 and DB20 = 1: Broadcast update. If
DB18 = 0, then SR data are ignored and all channels
are updated with previously stored data (or
power-down). If DB18 = 1, then SR data (or
power-down) updates all channels. Refer to Table 6
for more information.
Table 6. Control Matrix for the DAC7565
DB23
0
X
X
X
DB22
0
X
X
X
DB21
LD 1
0
0
0
0
0
0
0
1
1
1
1
1
DB20
LD 0
0
0
0
0
0
1
1
0
0
1
1
1
DB19
0
0
0
0
0
0
0
0
0
0
0
0
0
DB18
DAC Sel 1
0
0
1
1
DB17
DAC Sel 0
0
1
0
1
(00, 01, 10, or 11)
(00, 01, 10, or 11)
(00, 01, 10, or 11)
(00, 01, 10, or 11)
(00, 01, 10, or 11)
0
X
1
X
1
X
DB16
PD0
0
0
0
0
DB15 DB14 DB13-DB4
MSB MSB-1 MSB-2...LSB
Data
Data
Data
Data
1
See Table 7
0
0
Data
1
See Table 7
0
0
Data
1
See Table 7
0
Broadcast Modes
X
X
0
Data
1
See Table 7
0
DB3-DB0
Don't Care
DESCRIPTION
X
Write to buffer A with data
X
Write to buffer B with data
X
Write to buffer C with data
X
Write to buffer D with data
X
Write to buffer (selected by DB17 and DB18) with
power-down command
X
Write to buffer with data and load DAC (selected
by DB17 and DB18)
X
Write to buffer with power-down command and
load DAC (selected by DB17 and DB18)
Write to buffer with data (selected by DB17 and
X
DB18) and then load all DACs simultaneously
from their corresponding buffers
Write to buffer with power-down command
X
(selected by DB17 and DB18) and then load all
DACs simultaneously from their corresponding
buffers
Simultaneously update all channels of DAC7565
X
with data stored in each channels temporary
register
X
Write to all channels and load all DACs with SR
data
X
Write to all channels and load all DACs with
power-down command in SR
28
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