MAX4634
Fast, Low-Voltage, 4
Ω
,
4-Channel CMOS Analog Multiplexer
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Detailed Description
The MAX4634 is a low-on-resistance, low-voltage ana-
log multiplexer that operates from a +1.8V to +5.5V sin-
gle supply. CMOS switch construction allows pro-
cessing of analog signals that are within the supply volt-
age range (GND to V+).
To disable all switch channels, drive EN low. All four inputs
and COM become high impedance during this state. If the
disable feature is not needed, connect EN to V+.
Applications Information
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 sequencing 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-resis-
tance increases by a small amount at low supply 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 damage the device, even if the supply voltage
is below the signal voltage.
FUNCTION
1A0
Address Input. See the
Truth Table
for details.
2 NO1 Normally Open Switch 1
3 GND Ground
4 NO3 Normally Open Switch 3
5EN
Enable Logic Input. See the
Truth
Table
for details.
6V+
Positive Supply Voltage. Connect
to an external power supply.
Bypass to GND with a 10µF
capacitor placed as close to the
pin as possible.
7 NO4 Normally Open Switch 4
8 COM Analog Switch Common Terminal
9 NO2 Normally Open Switch 2
10 A1
Address Input. See the
Truth Table
for details.
—EP
Exposed Pad. Internally connected
to GND. Connect to a large PCB
ground plane for proper operation.
Not intended as an electrical
connection point (TDFN package
only).
