MAX399 Maxim, MAX399 Datasheet - Page 8

• Manufacturer Part Number: MAX399
• Description: The MAX398/MAX399 precision, monolithic, CMOS analog multiplexers (muxes) offer low on-resistance (less than 100Ω), which is matched to within 6Ω between channels and remains flat over the specified analog signal range (11Ω max)
• Manufacturer: Maxim

Using supply voltages less than ±5V reduces the analog
signal range. The MAX398/MAX399 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 device types can also operate with unbal-
anced supplies, such as +10V and -5V. The Typical
Operating Characteristics graphs show typical on-resis-
tance with ±3V, ±5V, +3V, and +5V supplies. (Switching
times increase by a factor of two or more for operation at
+5V.)
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
Precision, 8-Channel/Dual 4-Channel,
Low-Voltage, CMOS Analog Multiplexers
Figure 2. Transition Time
8
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50Ω
50Ω
Operation with Supply Voltages
Applications Information
V
V
EN
EN
A1
A2
A0
EN
A1
A0
EN
GND
GND
MAX399
MAX398
Overvoltage Protection
+5V
+5V
V+
V+
NO1A–NO4A
NO2–NO7
-5V
-5V
V-
V-
COMB
NO1B
NO4B
COM
NO1
NO8
Other than ±5V
300Ω
300Ω
-5V
+5V
+5V
-5V
35pF
35pF
V OUT
V OUT
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
SWITCH
OUTPUT
LOGIC
INPUT
V
V
EN
OUT
COM
Test Circuits/Timing Diagrams
V
V
+3V
NO1
NO8
0
0
t
TRANS
ON
*
*
50%
V-
V+
+5V
-5V
90%
D1
D2
* INTERNAL PROTECTION DIODES
*
*
t R < 20ns
t F < 20ns
MAX398
MAX399
90%
NO
t
TRANS