Datasheet

Applications Information
Analog Signal Levels
Analog signals can range over the supply voltage (V+ to
GND) with on-resistance changing very little over the
entire range (see Typical Operating Characteristics). The
MAX4594–MAX4597 are bidirectional, so the NO, NC,
and COM pins can be used either as inputs or outputs.
Power-Supply Sequencing and
Overvoltage Protection
Proper power-supply sequencing is recommended for
all CMOS devices. Always apply V+ before applying
analog signals or logic inputs, especially if the analog
or logic signals are not current limited. If this sequenc-
ing is not possible, and if the analog or logic inputs are
not current limited to <20mA, add a small-signal diode
(D1) as shown in Figure 1. If the analog signal can dip
below GND, add D2. Adding protection diodes
reduces the analog signal range to a diode drop (about
0.7V) below V+ for D1 or to a diode drop above ground
for D2. The addition of diodes does not affect leakage.
On-resistance increases by a small amount at low sup-
ply voltages. Maximum supply voltage (V+) must not
exceed 6V.
Protection diodes D1 and D2 also protect against some
overvoltage situations. A fault voltage up to the absolute
maximum rating at an analog signal input does not dam-
age the device, even if the supply voltage is below the
signal voltage.
MAX4594–MAX4597
Low-Voltage, Single-Supply,
10Ω SPST CMOS Analog Switches
6 _______________________________________________________________________________________
∆V
OUT
V+
0V
V
IN
V
OUT
MAX4595/MAX4597
MAX4594/MAX4596
∆V
OUT
IS THE MEASURED VOLTAGE DUE TO CHARGE TRANSFER
ERROR Q WHEN THE CHANNEL TURNS OFF.
Q = ∆V
OUT
x C
L
V+
V
OUT
GND
V+
IN
NO
or
NC
COM
V
NO
or V
NC
= 0
50Ω
MAX4594
MAX4595
MAX4596
MAX4597
C
L
1000pF
V
IN
Figure 2. Charge Injection
Test Circuits/Timing Diagrams
POSITIVE SUPPLY
COM
NO
OR
NC
D2
D1
GND
V
g
V+
Figure 1. Overvoltage Protection Using Two External Blocking
Diodes