ISL43L840 Datasheet, PDF (6/11 Pages) Intersil Corporation – Ultra Low ON-Resistance, Low-Voltage, Single Supply, Dual 4 to 1 Analog Multiplexer

ISL43L840
Test Circuits and Waveforms (Continued)
V+
C
V+
C
SIGNAL
GENERATOR
NO or NC
0V or V+
ADDX
ANALYZER
R_L
COM _GND
FIGURE 4. OFF ISOLATION TEST CIRCUIT
R_ON = V₁/100mA
V_NX
100mA
NO or NC
V₁
0V or V+
ADDX
COM
GND
FIGURE 5. R_ON TEST CIRCUIT
V+
C
SIGNAL
GENERATOR
50Ω
NO_A or NC_{A COMA}
ADDX
0V or V+
ANALYZER
R_L
COM_B
NO_B or NC_B
GND
N.C.
FIGURE 6. CROSSTALK TEST CIRCUIT
V+
C
IMPEDANCE
ANALYZER
NO or NC
0V or V+
ADDX
COM
GND
FIGURE 7. CAPACITANCE TEST CIRCUIT
Detailed Description
The ISL43L840 analog switches offer precise switching
capability from a single 1.6V to 3.6V supply with low on-
resistance (0.5Ω) and high speed operation (t_RANS = 19ns).
The device is especially well-suited to portable battery
powered equipment thanks to the low operating supply
voltage (1.6V), low power consumption (0.2µW), and low
leakage currents (60nA max). High frequency applications
also benefit from the wide bandwidth, and the very high off
isolation and crosstalk rejection.
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 GND (see
Figure 8). To prevent forward biasing these diodes, V+ must
be applied before any input signals, and the input signal
voltages must remain between V+ and GND. If these
6
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 8). 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.
This method is not applicable for the signal path inputs.
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 8). These
additional diodes limit the analog signal from 1V below V+ to
1V above GND. The low leakage current performance is
unaffected by this approach, but the switch signal range is
FN6096.1