Datasheet

MAX349/MAX350
Serially Controlled, Low-Voltage,
8-Channel/Dual 4-Channel Multiplexers
16 ______________________________________________________________________________________
SCLK
DIN
DOUT
CS
SK
SO
SI
I/O
MICROWIRE
PORT
MAX349
MAX350
THE DOUT-SI CONNECTION IS NOT REQUIRED FOR WRITING TO THE
MAX349/MAX350, BUT MAY BE USED FOR DATA-ECHO PURPOSES.
Figure 3. Connections for MICROWIRE
DOUT
DIN
SCLK
CS
MISO
MOSI
SCK
I/O
SPI
PORT
MAX349
MAX350
THE DOUT-MISO CONNECTION IS NOT REQUIRED FOR WRITING TO THE
MAX349/MAX350, BUT MAY BE USED FOR DATA-ECHO PURPOSES.
CPOL = 0, CPHA = 0
Figure 4. Connections for SPI and QSPI
SCLK
DIN
CS
MAX349
MAX350
SCLK
DIN
CS
MAX349
MAX350
SCLK
DIN
CS
MAX349
MAX350
DOUT DOUT DOUT
SCLK
DIN
CS
TO OTHER
SERIAL DEVICES
Figure 5. Daisy-Chained Connection
Dual, Differential 4-Channel Multiplexer
The MAX350 can be programmed normally, with only
one differential channel selected for every eight clock
pulses, or it can be programmed in a fast mode, where
channel changing occurs on each clock pulse.
In fast mode, select the channels by sending two high
pulses, spaced four clock pulses apart (corresponding
to the two selected channels) at DIN, and a corre-
sponding CS low pulse for each of the first eight clock
pulses. As SCLK clocks this through the register, each
switch sequences one differential channel at a time,
starting with channel 0. Repeat this process for subse-
quent channel sequencing after the first eight bits have
been sent. For even faster channel sequencing, send
only one DIN high pulse and one CS
low pulse for
every four clock pulses.
Reset Function
RESET is the internal reset pin. It is usually connected
to a logic signal or V+. Drive RESET low to open all
switches and set the contents of the internal shift regis-
ter to zero simultaneously. When RESET is high, the
part functions normally and DOUT is sourced from V+.
RESET must not be driven beyond V+ or GND.