MAX5354 Maxim, MAX5354 Datasheet - Page 10

• Manufacturer Part Number: MAX5354
• Description: 10-Bit Voltage-Output DACs in 8-Pin MAX
• Manufacturer: Maxim

10-Bit Voltage-Output DACs
in 8-Pin µMAX
In shutdown mode, the amplifier’s output and the refer-
ence input enter a high-impedance state. The serial
interface remains active. Data in the input register is
retained in shutdown, allowing the MAX5354/MAX5355
to recall the output state prior to entering shutdown. Exit
shutdown mode by either recalling the previous configu-
ration or updating the DAC with new data. When power-
ing up the device or bringing it out of shutdown, allow
20µs for the outputs to stabilize.
The MAX5354/MAX5355’s 3-wire serial interface is com-
patible with both Microwire™ (Figure 2) and
SPI™/QSPI™ (Figure 3). The serial input word consists of
three control bits followed by 10+3 data bits (MSB first),
as shown in Figure 4. The 3-bit control code determines
the MAX5354/MAX5355’s response outlined in Table 1.
The MAX5354/MAX5355’s digital inputs are double
buffered. Depending on the command issued through
the serial interface, the input register can be loaded
without affecting the DAC register, the DAC register can
be loaded directly, or the DAC register can be updated
from the input register (Table 1).
The +3.3V MAX5355 can also directly interface with +5V
logic.
The MAX5354/MAX5355 require 16 bits of serial data.
Table 1 lists the serial-interface programming com-
mands. For certain commands, the 10+3 data bits are
“don’t cares.” Data is sent MSB first and can be sent in
two 8-bit packets or one 16-bit word (CS must remain
low until 16 bits are transferred). The serial data is com-
posed of three control bits (C2, C1, C0), followed by the
10+3 data bits D9...D0, S2, S1, S0 (Figure 4). Set the
sub-bits (S2, S1, S0) to zero. The 3-bit control code
determines:
Figure 5 shows the serial-interface timing requirements.
The chip-select pin (CS) must be low to enable the
DAC’s serial interface. When CS is high, the interface
control circuitry is disabled. CS must go low at least
t
properly clock in the first bit. When CS is low, data is
clocked into the internal shift register via the serial-data
input pin (DIN) on SCLK’s rising edge. The maximum
guaranteed clock frequency is 10MHz. Data is latched
into the MAX5354/MAX5355 input/DAC register on CS’s
rising edge.
10
CSS
______________________________________________________________________________________
the register to be updated,
the configuration when exiting shutdown.
before the rising serial clock (SCLK) edge to
Serial-Interface Configurations
Serial-Interface Description
Figure 2. Connections for Microwire
Figure 3. Connections for SPI/QSPI
Figure 4. Serial-Data Format
C2
MSB ..................................................................................LSB
3 Control
Control
MAX5354
MAX5355
MAX5354
MAX5355
C1
Bits
Bits
C0
SCLK
SCLK
16 Bits of Serial Data
DIN
DIN
CS
CS
MSB............................LSB Sub-Bits
D9 ...............................D0, S2, S1, S0
10+3 Data Bits
Data Bits
CPOL = 0, CPHA = 0
MOSI
SCK
I/O
SK
SO
I/O
MICROWIRE
SPI/QSPI
PORT
PORT
+5V
SS