Datasheet

MAX4680/MAX4690/MAX4700
1.25 Ω , Dual SPST,
CMOS Analog Switches
8 _______________________________________________________________________________________
___________Applications Information
Overvoltage Protection
Proper power-supply sequencing is recommended for
all CMOS devices. Do not exceed the absolute maxi-
mum ratings because stresses beyond the listed rat-
ings can cause permanent damage to the devices.
Always sequence V+ on first, then V-, followed by the
logic inputs, NO, or COM. If power-supply sequencing
is not possible, add two small signal diodes (D1, D2) in
series with the supply pins and a Schottky diode
between V+ and V
L
for overvoltage protection (Figure
1). Adding diodes reduces the analog signal range to
one diode drop below V+ and one diode drop above V-,
but does not affect the devices’ low switch resistance
and low-leakage characteristics. Device operation is
unchanged, and the difference between V+ and V-
should not exceed 44V.
COM_
V
L
V-
V+
NO_
* INTERNAL PROTECTION DIODES
D2
D1
-15V
+15V
MAX4680
MAX4690
MAX4700
*
*
*
*
t
r
< 20ns
t
f
< 20ns
50%
0
LOGIC
INPUT
V-
-15V
R
L
100Ω
NO_
OR NC_
GND
C
L
INCLUDES FIXTURE AND STRAY CAPACITANCE.
SWITCH
INPUT
IN_
+3V
t
OFF
0
COM_
SWITCH
OUTPUT
0.9V
0
0.9V
0
t
ON
V
O
SWITCH
OUTPUT
LOGIC
INPUT
LOGIC INPUT WAVEFORMS INVERTED FOR SWITCHES
THAT HAVE THE OPPOSITE LOGIC SENSE.
V
L
V+
C
L
35pF
+5V
+15V
V
O
V
COM_
0
REPEAT TEST FOR EACH SWITCH. FOR LOAD
CONDITIONS, SEE
Electrical Characteristics.
MAX4680
MAX4690
MAX4700
V
O
= V
COM
( )
R
L
+ R
ON
R
L
Figure 1. Overvoltage Protection Using External Blocking Diodes
Figure 2. Switching-Time Test Circuit