ISL54500 Datasheet, PDF (7/13 Pages) Intersil Corporation – +1.8V to +5.5V, 5OHM, Single SPDT Analog Switch

ISL54500
Test Circuits and Waveforms (Continued)
V+
C
V+
C
SIGNAL
GENERATOR
NO OR NC
IN _{0V OR V+}
r_ON = V₁/I₁ ^*
V_NX
NO OR NC
I₁
V₁
100mA
IN ^{VINL OR VINH}
ANALYZER
R_L
COM
GND
COM
GND
* _{I1 = 10mA AT V+ = 1.8V}
FIGURE 4. OFF-ISOLATION TEST CIRCUIT
V+
C
50Ω _{NO OR NC}
COM
FIGURE 5. r_ON TEST CIRCUIT
V+
C
NO OR NC
IN₁
0V or V+
ANALYZER
R_L
NC OR NO
GND
SIGNAL
GENERATOR
IMPEDANCE
ANALYZER
IN V_INL OR V_INH
COM
GND
FIGURE 6. CROSSTALK TEST CIRCUIT
Detailed Description
The ISL54500 is a bi-directional, single pole/double
throw (SPDT) analog switch that offers precise
switching capability from a single 1.8V to 5.5V supply
with low ON-resistance (5Ω) and high speed operation
(t_ON = 22ns, t_OFF = 15ns). The device is especially
well suited for portable battery powered equipment
due to its low operating supply voltage (1.8V), low
power consumption (0.11µW), low leakage currents
(300nA max) and small µTDFN and SOT-23 packages.
The low ON-resistance and r_ON flatness provide very
low insertion loss and distortion to application that
require signal reproduction.
External V+ Series Resistor
For improved ESD and latch-up immunity Intersil
recommends adding a 100Ω resistor in series with the
V+ power supply pin of the ISL54050 IC
(see Figure 8).
During an overvoltage transient event (such as occurs
during system level IEC 61000 ESD testing), substrate
currents can be generated in the IC that can trigger
7
FIGURE 7. CAPACITANCE TEST CIRCUIT
parasitic SCR structures to turn ON, creating a low
impedance path from the V+ power supply to ground.
This will result in a significant amount of current flow in
the IC, which can potentially create a latch-up state or
permanently damage the IC. The external V+ resistor
limits the current during this over-stress situation and
has been found to prevent latch-up or destructive
damage for many over voltage transient events.
Under normal operation, the sub-microamp I_DD
current of the IC produces an insignificant voltage drop
across the 100Ω series resistor resulting in no impact
to switch operation or performance.
FN6549.2
November 9, 2009