Datasheet

MAX381/MAX383/MAX385
Precision, Low-Voltage Analog Switches
8 _______________________________________________________________________________________
__________Applications Information
Operation with Supply Voltages
Other than ±5V
The MAX381/MAX383/MAX385 switches operate with
±3.0V to ±8V bipolar supplies and a +3V to +15V single
supply. In either case, analog signals ranging from V+ to
V- can be switched. The Typical Operating Characteristics
graphs show the typical on-resistance variation with ana-
log signal and supply voltage. The usual on-resistance
temperature coefficient is 0.5%/°C (typ).
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 3V
supply.
______________________________________________________________Pin Description
COM
V-
V+
NO
* INTERNAL PROTECTION DIODES
D2
D1
-5V
+5V
MAX381
MAX383
MAX385
*
*
*
*
Figure 1. Overvoltage Protection Using Two External Blocking
Diodes
1, 8 COM_ Analog Switch Common Terminal
2–7, 12 N.C. Not Internally Connected
9, 16 NO_ Analog Switch Normally Open Terminal
— NC_ Analog Switch Normally Closed Terminal
10, 15 IN_* Logic Level Input (Normally Low)
11 V+ Analog Signal and Logic Positive Supply Input
14 V- Analog Signal Negative Supply Input
NAME FUNCTION
MAX381
1, 3, 6, 8
2, 7, 12
9, 16
4, 5
10, 15
11
14
MAX383
1, 3, 6, 8
2, 7, 12
4, 5, 9, 16
—
10, 15
11
14
MAX385
PIN
13 GND Logic Negative Supply Input (Ground)13 13
* IN1 controls COM1 and COM3; IN2 controls COM2 and COM4.