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.

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 maximum rat-

ings, because stresses beyond the listed ratings 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 over-

voltage 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.

Figure 1. Overvoltage Protection Using External Blocking Diodes

COM

V-

V+

NO

*INTERNAL PROTECTION DIODES

D2

D1

-5V

+5V

*

*

*

*

MAX396

MAX397

MAX396/MAX397

Precision, 16-Channel/Dual 8-Channel,

Low-Voltage, CMOS Analog Multiplexers

www.maximintegrated.com

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