Datasheet

Click-Pop Suppression
The MAX4908 has a 3.8kΩ (typ) shunt resistor on all of
its input terminals to automatically discharge any
capacitance when they are not connected to common
terminal X and Y. The MAX4909 has shunt resistors on
all terminals except X0 and Y0. The MAX4930 only has
shunt resistors on X2 and Y2. The shunt resistors
reduce audible click-and-pop sounds that occur when
switching between audio sources.
Audible clicks and pops are caused when a step DC
voltage is switched into the speaker. The DC step tran-
sients can be reduced by automatically discharging the
side that is not connected to the common terminal, thus
reducing any residual DC voltage and clicks and pops.
Break-Before-Make Switching
The MAX4908/MAX4909/MAX4930/MAX4932 feature
break-before-make switching, which is configured to
break (open) the first set of contacts before engaging
(closing) the new contacts. This prevents the momen-
tary connection of the old and new signal paths to the
output, further reducing click-and-pop sounds.
MAX4908/MAX4909/MAX4930/MAX4932
Dual 3:1 Clickless Audio Multiplexers
with Negative-Signal Handling
_______________________________________________________________________________________ 7
GND
MAX4908
CB1
V
CC
CB2
X0
X1
X2
X
Y0
Y1
Y2
Y
CONTROL
LOGIC
CB1 = 0, CB2 = 1
GND
MAX4909
CB1
V
CC
CB2
X0
X1
X2
X
Y0
Y1
Y2
Y
CONTROL
LOGIC
CB1 = 0, CB2 = 1
DISCHARGE PATHS HAVE A 3.8kΩ RESISTOR (NOT SHOWN).
Functional Diagram