ISL84516_05 Datasheet, PDF (5/10 Pages) Intersil Corporation – Low-Voltage, Dual Supply, SPST, Analog Switches

ISL84516, ISL84517
Test Circuits and Waveforms (Continued)
V+
C
SIGNAL
GENERATOR
NO or NC
IN ^{V- or V+}
R_ON = V₁/1mA
COM
V_COM
1mA
V₁
V+
C
IN ^{VINL or VINH}
ANALYZER
COM
R_L
C
V-
FIGURE 3. OFF ISOLATION TEST CIRCUIT
NO or NC
C
V-
FIGURE 4. R_ON TEST CIRCUIT
IMPEDANCE
ANALYZER
V+
NO or NC
COM
IN ^{V- or V+}
V-
FIGURE 5. CAPACITANCE TEST CIRCUIT
Detailed Description
The ISL84516 and ISL84517 analog switches offer precise
switching capability from ±1.5V to ±6V supplies with low on-
resistance (13Ω) and high speed operation (t_ON = 40ns,
t_OFF = 30ns). The devices are especially well suited to
portable battery powered equipment thanks to the low
operating supply voltage (±1.5V), low power consumption
(350µW), low leakage currents (2nA max), and the tiny
SOT-23 packaging. High frequency applications also benefit
from the wide bandwidth, and the very high off isolation.
Supply Sequencing And Overvoltage Protection
With any CMOS device, proper power supply sequencing is
required to protect the device from excessive input currents
which might permanently damage the IC. All I/O pins contain
ESD protection diodes from the pin to V+ and to V- (see
Figure 6). To prevent forward biasing these diodes, V+ and
5
V- must be applied before any input signals, and input signal
voltages must remain between V+ and V-. If these conditions
cannot be guaranteed, then one of the following two
protection methods should be employed.
Logic inputs can easily be protected by adding a 1kΩ
resistor in series with the input (see Figure 6). The resistor
limits the input current below the threshold that produces
permanent damage, and the sub-microamp input current
produces an insignificant voltage drop during normal
operation.
Adding a series resistor to the switch input defeats the
purpose of using a low R_ON switch, so two small signal
diodes can be added in series with the supply pins to provide
overvoltage protection for all pins (see Figure 6). These
additional diodes limit the analog signal from 1V below V+ to
1V above V-. The low leakage current performance is