Datasheet

MAX4539/MAX4540
Low-Voltage, Single 8-to-1 and
Dual 4-to-1 Cal-Multiplexers
______________________________________________________________________________________ 13
Single-Supply Operation
The MAX4539/MAX4540 operate from a single supply
between +2.7V and +12V when V- is connected to
GND. All of the bipolar precautions must be observed.
However, these parts are optimized for ±5V operation,
and most AC and DC characteristics are degraded sig-
nificantly when departing from ±5V. As the overall sup-
ply voltage (V+ to V-) is lowered, switching speed,
on-resistance, off isolation, and distortion will degrade.
(see the Typical Operating Characteristics section).
Single-supply operation also limits signal levels and
interferes with ground referenced signals. When V- = 0,
AC signals are limited to -0.3V. Voltages below -0.3V can
be clipped by the internal ESD-protection diodes, and
the parts can be damaged if excessive current flows.
Power Up
During power up, on-chip latches will strobe whatever
addresses are present if EN goes high before LATCH
reaches a logic high. When this condition occurs, one of
the internal dividers connected between the supplies
may inadvertently turn on, causing higher supply current
(~200µA supply current) when the enable input is tog-
gled. Avoid this condition by ensuring that EN pin stays
low until the remaining logic inputs are valid. To accom-
plish this, connect a resistor from EN to ground or apply
a low voltage to EN before the other logic inputs go high.
Power Off
When power to the MAX4539/MAX4540 is off (i.e., V+ =
V- = 0), the Absolute Maximum Ratings still apply. This
means that neither logic-level inputs on NO_ nor sig-
nals on COM_ can exceed ±0.3V. Voltages beyond
±0.3V cause the internal ESD-protection diodes to con-
duct, and the parts can be damaged if excessive cur-
rent flows.
Chip Information
TRANSISTOR COUNT: 561
Test Circuits/Timing Diagrams
50%
50%
t
R
< 20ns
t
F
< 20ns
V
COM
V+
0V
V
NO1
, V
NO1B
0V
V
NO8
, V
NO4B
LOGIC
INPUT
V
EN
SWITCH
OUTPUT
+5V
-5V
GND
V+
V+
V+
A1
A2
V-
EN
LATCH
CAL
A0
NO1
NO2–NO7
NO8
COM
+3V
-3V
50Ω
MAX4539
300Ω
35pF
A1
A0
+5V
V
COM
V
COM
-5V
GND
V+
V-
EN
NO1B
NO2B–NO3B
NO1A–NO2A
NO4B
COMB
+3V
50Ω
MAX4540
300Ω
35pF
90%
90%
t
TRANS
t
TRANS
-3V
LATCH
CAL
Figure 1. Transition Time