
MAX396/MAX397
Precision, 16-Channel/Dual 8-Channel,
Low-Voltage, CMOS Analog Multiplexers
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7
______________________________________________________________Pin Description
—
PIN
MAX396 MAX397 NAME FUNCTION
1 V+ Positive Supply-Voltage Input
2, 3, 13 1N.C. No Internal Connection
— 2 COMB Analog Signal B Output* (bidirectional)
— 3, 13, 14 N.C. No Internal Connection
4–11 — NO16–NO9 Analog Signal Inputs* (bidirectional)
— 4–11 NO8B–NO1B Analog Signal B Inputs* (bidirectional)
12 12 GND Logic Ground
14–17 — A3–A0 Logic Address Inputs
— 15, 16, 17 A2, A1, A0 Logic Address Inputs
18 18 EN Logic Enable Input
19–26 — NO1–NO8 Analog Signal Inputs* (bidirectional)
— 19–26 NO1A–NO8A Analog Signal A Inputs* (bidirectional)
27 27 V- Negative Supply-Voltage Input
28 — COM Analog Signal Output* (bidirectional)
— 28 COMA Analog Signal A Output* (bidirectional)
__________Applications Information
Operation with Supply Voltages
Other than ±5V
Using supply voltages less than ±5V reduces the analog
signal range. The MAX396/MAX397 multiplexers (muxes)
operate with ±3V to ±8V bipolar supplies or with a +3V to
+15V single supply. Connect V- to GND when operating
with a single supply. Both devices can also operate with
unbalanced supplies, such as +10V and -5V. The
Typical
Operating Characteristics
graphs show typical on-
resistance with ±3V, ±5V, +3V, and +5V supplies.
(Switching times increase by a factor of two or more for
operation at 5V or below.)
These muxes operate with a single supply as low as 1V,
although on-resistance and switching times become
extremely high. Performance is not guaranteed below
2.7V. This is useful information only because it assures
proper switch state while power supplies ramp up or
down slowly.
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 supply pins 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 17V. These protection
diodes are not recommended when using a single supply.
*Analog signal inputs and outputs are names of convenience only; they are identical and interchangeable.
COM
V-
V+
NO
*INTERNAL PROTECTION DIODES
D2
D1
-5V
+5V
MAX396
MAX397
*
*
*
*
Figure 1. Overvoltage Protection Using External Blocking Diodes