Datasheet

Break-Before-Make Switching
All devices feature break-before-make switching, which
is configured to break (open) the first set of contacts
before engaging (closing) the new contacts. This pre-
vents the momentary connection of the old and new sig-
nal paths to the output, reducing click-and-pop sounds.
Power-Supply Sequencing and
Overvoltage Protection
Caution: Do not exceed the Absolute Maximum
Ratings since stresses beyond the listed ratings
may cause permanent damage to the device.
Proper power-supply sequencing is recommended for
all CMOS devices. Improper supply sequencing can
force the switch into latch-up, causing it to draw exces-
sive supply current. The only way out of latch-up is to
recycle the power and reapply properly. Connect all
ground pins first, then apply power to V
CC
, and finally
apply signals to NO_, NC_, and COM_. Follow the
reverse order upon power-down.
MAX4744/MAX4744H/MAX4745/MAX4745H/MAX4746H
Low-Voltage, Dual SPDT, Audio Clickless
Switches with Negative Rail Capability
10 ______________________________________________________________________________________
GND
NC_
OR NO_
C
L
V
OUT
V
CC
V
OUT
CB_
OFF
ON
OFF
ΔV
OUT
Q = (ΔV
OUT
)(C
L
)
COM_
LOGIC INPUT WAVEFORMS INVERTED FOR SWITCHES
THAT HAVE THE OPPOSITE LOGIC SENSE.
OFF
ON
OFF
CB_
V
IL
TO V
IH
V
CC
CB_
MAX4744/MAX4745/
MAX4744H/MAX4745H/
MAX4746H
Figure 4. Charge Injection
V
CC
GND
V
CC
COM_
NO_
MEASUREMENTS ARE STANDARDIZED AGAINST SHORT AND OPEN AT SOCKET TERMINALS.
OFF-ISOLATION IS MEASURED BETWEEN COM_ AND OFF NO_ OR NC_ TERMINALS.
ON-LOSS IS MEASURED BETWEEN COM_ AND ON NO_ OR NC_ TERMINAL ON EACH SWITCH.
CROSSTALK IS MEASURED FROM ONE CHANNEL TO THE OTHER CHANNEL.
SIGNAL DIRECTION THROUGH SWITCH IS REVERSED; WORST VALUES ARE RECORDED.
NC_
10nF
V
IN
V
OUT
NETWORK
ANALYZER
50Ω 50Ω
50Ω 50Ω
MEAS REF
MAX4744
MAX4744H
MAX4746H
CB_
0V OR
V
CC
OFF-ISOLATION = 20log
OFF-LOSS = 20log
CROSSTALK = 20log
V
IN
V
OUT
V
IN
V
OUT
V
IN
V
OUT
Figure 5. Off-Isolation, On-Loss, and Crosstalk
Test Circuits/Timing Diagrams