MAX4525 Datasheet, PDF (8/14 Pages) Maxim Integrated Products – Low-Voltage, Single-Supply Multiplexer and Switch

Low-Voltage, Single-Supply
Multiplexer and Switch
There is no connection between the analog signal
paths and GND. V+ and GND power the internal logic
and logic-level translators, and set both the input and
output logic limits. The logic-level translators convert
the logic levels into switched V+ and GND signals to
drive the gates of the analog signals. This drive signal
is the only connection between the logic supplies (and
signals) and the analog supplies. V+ has an ESD-pro-
tection diode to GND.
Low-Voltage Operation
These devices operate from a single supply between
+2V and +12V. At room temperature, they actually
“work” with a single supply at near or below +1.7V,
although as supply voltage decreases, switch on-resis-
tance and switching times become very high.
High-Frequency Performance
In 50Ω systems, signal response is reasonably flat up
to 50MHz (see Typical Operating Characteristics).
Above 20MHz, the on-response has several minor
peaks, which are highly layout dependent. The problem
is not turning the switch on, but turning it off. The off-
state switch acts like a capacitor, and passes higher
frequencies with less attenuation. At 10MHz, off-isola-
tion is about -50dB in 50Ω systems, becoming worse
(approximately 20dB per decade) as frequency
increases. Higher circuit impedances also degrade off-
isolation. Adjacent channel attenuation is about 3dB
above that of a bare IC socket, and is entirely due to
capacitive coupling.
_________________________________Test Circuits/Timing Diagrams (continued)
V+
V+
ADDA
NO0
V+
ADDB
NO1–NO3
MAX4524
V_INH
INH
COM
GND
50Ω
300Ω
V_OUT
35pF
V+
V_INH
50%
0V
V_NO0
V_OUT
90%
0V
t_ON
90%
t_OFF
V+
V+
ADD
NO_
V+
NC_
MAX4525
V_INH
INH
COM_
GND
50Ω
300Ω
V_OUT
35pF
V+
V_INH
50%
0V
V_{NO_}
V_OUT
90%
0V
t_ON
90%
t_OFF
REPEAT TEST FOR EACH SECTION.
Figure 2. Inhibit Switching Times
8 _______________________________________________________________________________________