Datasheet
__________Applications Information
Operation with
Supply Voltages Other than 15V
Using supply voltages less than ±15V will reduce the
analog signal range. The MAX308/MAX309 switches
operate with ±5V to ±20V bipolar supplies or with a
+5V to +30V single supply. Connect V- to GND when
operating with a single supply. Both device types can
also operate with unbalanced supplies, such as +24V
and -5V. The Typical Operating Characteristics graphs
show typical on-resistance with 20V, 15V, 10V, and 5V
supplies. (Switching times increase by a factor of two
or more for operation at 5V.)
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 may 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 in series
with supply pins for overvoltage protection (Figure 1).
Adding diodes reduces the analog signal range to 1V
below V+ and 1V above V-, but does not affect the
devices’ low switch resistance and low leakage charac-
teristics. Device operation is unchanged, and the differ-
ence between V+ and V- should not exceed +44V.
MAX308/MAX309
Precision, 8-Channel/Dual 4-Channel,
High-Performance, CMOS Analog Multiplexers
6 _______________________________________________________________________________________
______________________________________________________________Pin Description
V
g
NO
COM
V-
V+
Figure 1. Overvoltage Protection Using External Blocking
Diodes
PIN
MAX308 MAX309
NAME FUNCTION
1, 15, 16 A0, A2, A1 Address Inputs
—
—
A0, A1 Address Inputs
2 2 EN Enable Input
3 3 V- Negative Supply Voltage Input
4–7 — NO1–NO4 Analog Inputs—Bidirectional
— 4–7 NO1A–NO4A Analog Inputs—Bidirectional
8 — COM Analog Output—Bidirectional
— 8, 9 COMA, COMB Analog Outputs—Bidirectional
9–12 — NO8–NO5 Analog Inputs—Bidirectional
— 10–13 NO4B–NO1B Analog Inputs—Bidirectional
13 14 V+ Positive Supply Voltage Input
14 15 GND Ground
1, 16