Low-Voltage, CMOS Analog
Multiplexers/Switches
MAX4051/A, MAX4052/A, MAX4053/A
Table 1. Truth Table/Switch Programming
ADDRESS BITS
INH
1
0
ADDC*
X
0
ADDB
X
0
ADDA
X
0
MAX4051/
MAX4051A
All switches open
COM鈥揘O0
ON SWITCHES
MAX4052/
MAX4052A
All switches open
COMB鈥揘O0B,
COMC鈥揘O0C
COMB鈥揘O1B,
COMC鈥揘O1C
COMB鈥揘O2B,
COMC鈥揘O2C
COMB鈥揘O3B,
COMC鈥揘O3C
COMB鈥揘O0B,
COMC鈥揘O0C
COMB鈥揘O1B,
COMC鈥揘O1C
COMB鈥揘O2B,
COMC鈥揘O2C
COMB鈥揘O3B,
COMC鈥揘O3C
MAX4053/
MAX4053A
All switches open
COMA鈥揘CA,
COMB鈥揘CB,
COMC鈥揘CC
COMA鈥揘OA,
COMB鈥揘CB,
COMC鈥揘CC
COMA鈥揘CA,
COMB鈥揘OB,
COMC鈥揘CC
COMA鈥揘OA,
COMB鈥揘OB,
COMC鈥揘CC
COMA鈥揘CA,
COMB鈥揘CB,
COMC鈥揘OC
COMA鈥揘OA,
COMB鈥揘CB,
COMC鈥揘OC
COMA鈥揘CA,
COMB鈥揘OB,
COMC鈥揘OC
COMA鈥揘OA,
COMB鈥揘OB,
COMC鈥揘OC
0
0
0
1
COM鈥揘O1
0
0
1
0
COM鈥揘O2
0
0
1
1
COM鈥揘O3
0
1
0
0
COM鈥揘O4
0
1
0
1
COM鈥揘O5
0
1
1
0
COM鈥揘O6
0
1
1
1
COM鈥揘O7
X = Don鈥檛 care
* ADDC not present on MAX4052.
Note:
NO and COM pins are identical and interchangeable. Either may be considered an input or output; signals pass equally well
in either direction.
__________Applications Information
Power-Supply Considerations
Overview
The MAX4051/MAX4052/MAX4053 and MAX4051A/
MAX4052A/MAX4053A construction is typical of most
CMOS analog switches. They have three supply pins:
V+, V-, and GND. V+ and V- are used to drive the inter-
nal CMOS switches and set the limits of the analog volt-
age on any switch. Reverse ESD-protection diodes are
internally connected between each analog signal pin
and both V+ and V-. If any analog signal exceeds V+ or
V-, one of these diodes will conduct. During normal
operation, these (and other) reverse-biased ESD diodes
leak, forming the only current drawn from V+ or V-.
Virtually all the analog leakage current comes from the
ESD diodes. Although the ESD diodes on a given signal
pin are identical, and therefore fairly well balanced,
they are reverse biased differently. Each is biased by
either V+ or V- and the analog signal. This means their
leakages will vary as the signal varies. The
difference
in
the two diode leakages to the V+ and V- pins consti-
tutes the analog signal path leakage current. All analog
leakage current flows between each pin and one of the
supply terminals, not to the other switch terminal. This is
why both sides of a given switch can show leakage cur-
rents of either the same or opposite polarity.
There is no connection between the analog signal
paths and GND.
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