MAX4576 Maxim, MAX4576 Datasheet - Page 8

• Manufacturer Part Number: MAX4576
• Description: The MAX4575/MAX4576/MAX4577 are low-voltage, high electrostatic discharge (ESD)-protected, dual single-pole/single-throw (SPST) analog switches
• Manufacturer: Maxim

±15kV ESD-Protected, Low-Voltage, Dual, SPST,
CMOS Analog Switches
Figure 3. Charge Injection
Figure 4. Channel Off/On-Capacitance
and bypass the surge safely to ground. This method is
superior to using diode clamps to the supplies
because, unless the supplies are very carefully decou-
pled through low-ESR capacitors, the ESD current
through the diode clamp could cause a significant
spike in the supplies. This may damage or compromise
the reliability of any other chip powered by those same
supplies.
There are diodes from NC/NO to the supplies in addi-
tion to the SCRs. There is a resistance in series with
each of these diodes to limit the current into the sup-
plies during an ESD strike. The diodes protect these
8
CAPACITANCE
_______________________________________________________________________________________
f = 1MHz
METER
V
MAX4575
MAX4576
MAX4577
GEN
R
GEN
COM
10nF
GND
COM
NO_/NC_
GND
V+
V+
IN
V
IN
NO_/NC_
V+
V+
IN
MAX4575
MAX4576
MAX4577
V
C
IL
V
L
IH
OR
V
OUT
terminals from overvoltages that are not a result of ESD
strikes. These diodes also protect the device from
improper power-supply sequencing.
Once the SCR turns on because of an ESD strike, it
continues to be on until the current through it falls
below its “holding current.” The holding current is typi-
cally 110mA in the positive direction (current flowing
into the NC/NO terminal) at room temperature (see SCR
Holding Current vs. Temperature in the Typical
Operating Characteristics). Design the system so that
any sources connected to NC/NO are current limited to
a value below the holding current to ensure the SCR
Figure 5. Crosstalk
V
OUT
IN
SIGNAL
GENERATOR 0dBm
ANALYZER
OFF
0 OR 2.4V
R
L
Q = (∆V
10nF
COM1
IN1
NO2/NC2
ON
OUT
GND
V+
V+
)(C
L
)
∆V
NO1/NC1
OUT
COM2
IN2
OFF
MAX4575
MAX4576
MAX4577
50Ω
0 OR
2.4V
NC