32-Channel, 16-Bit, Voltage-Output

DACs with Serial Interface

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21

SING

When SING = 0 (default power-up mode), the device is

in daisy-chain mode. DOUT follows DIN after 32 clock

cycles. For the read command, DOUT provides the

read data in the next cycle following

CS rising edge.

The 16 data bits of the previous command word are

clocked out on the last 16 clock cycles of the current

command word.

When SING = 1, the device is in stand-alone mode. To

reduce the time it takes to read data out, the read data is

provided at DOUT as the 16 data bits of the current com-

mand are clocked in. The device acts on an incoming

command word independent of the rising edge of

CS.

Daisy Chain Operation

Any number of the MAX5732–MAX5735 devices can be

daisy chained by connecting the DOUT of one device to

the DIN of another device in a chain. All devices must be

in SING = 0 mode. Connecting the

CS inputs of all

devices together eliminates the need to issue NOP com-

mands to devices early in the chain (see Figure 4).

Data Readback

The contents of the MAX5732–MAX5735 DAC and con-

figuration registers can be read on DOUT by issuing a

read-data command. Setting control bits C2, C1, and

C0 = 100, puts the device in read-data mode. The

address bits select the register to be read. The con-

tents of the register (16 data bits) are clocked out at

DOUT. The output-data format depends on the status of

DSP and SING. Table 10 shows the manner in which

data is written to DOUT. Note that when the device is in

DSP mode (

DSP = 0), only the 16-bit data of the selected

register is written to DOUT.

Table 10. Read-Data Modes with SING and

DSP Controls

DSP

SING

CONFIGURATION

DESCRIPTION

READ DATA AT DOUT

0

0

Stand alone

DOUT provides the 16 data bits from the previous command word. Data

appears at DOUT on the last 16 clock edges of the current command word.

See Figure 7.

0

1

Stand alone

DOUT provides the 16 data bits from the current command word. Data appears at

DOUT on the last 16 clock edges of the current command word. See Figure 7.

1

0

Daisy chain

Data on DOUT follows the current command word after 32 clock cycles. For

read commands, the read data from the previous command word appears at

DOUT on the last 16 clock edges of the current command word. See Figure 4.

11

Multiple DOUTs connected

in parallel (not daisy

chained)

DOUT provides the 16 data bits from the current command word. Data appears

at DOUT on the last 16 clock edges of the current command word. For read

commands, the read data from the current command word appears at DOUT

on the last 16 clock edges of the current command word. See Figures 8 and 9.

CONTROLLER

DEVICE

DIN(0)

DOUT(0)

1

SCLK

CS

DSP

MAX573_

DIN(1)

DOUT(1)

SCLK

CS

DSP

MAX573_

DIN(2)

DOUT(2)

SCLK

CS

DSP

MAX573_

Figure 4. Daisy-Chain Configuration