Serially Controlled, Low-Voltage,

8-Channel SPST Switch

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13

8x1 Multiplexer

To use the MAX395 as an 8x1 multiplexer, connect all

common pins together (COM0–COM7) to form the mux

output; the mux inputs are NO0–NO7.

The mux can be programmed normally, with only one

channel selected for every eight clock pulses, or it can

be programmed in a fast mode, where channel chang-

ing occurs on each clock pulse. In this mode, the chan-

nels are selected by sending a single high pulse

(corresponding to the selected channel) at DIN, and a

corresponding CS low pulse for every eight clock puls-

es. As this is clocked through the register by SCLK,

each switch sequences one channel at a time, starting

with Channel 7.

Dual, Differential 4-Channel Multiplexer

To use the MAX395 as a dual (4x2) mux, connect

COM0–COM3 together and connect COM4–COM7

together, forming the two outputs. The mux input pairs

become NO0/NO4, NO1/NO5, NO2/NO6, and NO3/NO7.

The mux can be programmed normally, with only one

differential channel selected for every eight clock puls-

es, or it can be programmed in a fast mode, where

channel changing occurs on each clock pulse.

In fast mode, the channels are selected by sending two

high pulses spaced four clock pulses apart (corre-

sponding to the two selected channels) at DIN, and a

corresponding CS low pulse for each of the first eight

clock pulses. As this is clocked through the register by

SCLK

DIN

DOUT

CS

SK

SO

SI

I/O

MICROWIRE

PORT

MAX395

THE DOUT-SI CONNECTION IS NOT REQUIRED FOR WRITING TO THE

MAX395, BUT MAY BE USED FOR DATA-ECHO PURPOSES.

Figure 3. Connections for Microwire

DOUT

DIN

SCLK

CS

MISO

MOSI

SCK

I/O

SPI

PORT

MAX395

THE DOUT-MISO CONNECTION IS NOT REQUIRED FOR WRITING TO THE

MAX395, BUT MAY BE USED FOR DATA-ECHO PURPOSES.

CPOL = 0, CPHA = 0

Figure 4. Connections for SPI and QSPI

SCLK

DIN

CS

MAX395

SCLK

DIN

CS

MAX395

SCLK

DIN

CS

MAX395

DOUT

DOUT

DOUT

SCLK

DIN

CS

TO OTHER

SERIAL DEVICES

Figure 5. Daisy-Chained Connection