ISL73841SEH Datasheet, PDF (19/23 Pages) Intersil Corporation – Radiation Tolerant 30V 32-Channel Analog Multiplexer

ISL73841SEH
Post Low Dose Rate Radiation Characteristics (V± = ±12V) Unless otherwise
specified, V± = ±12V, V_CM = 0, V_O = 0V, T_A = +25°C. This data is typical mean test data post radiation exposure at a low dose rate of <10mrad(Si)/s. This
data is intended to show typical parameter shifts due to low dose rate radiation. These are not limits nor are they guaranteed. (Continued)
25
300
20
BIASED
15
10
5
0
-5
GROUNDED
250
200
150
100
GROUNDED
50
BIASED
-10
0
10
20
30
40
50
60
LOW DOSE RATE RADIATION (krad(Si))
FIGURE 53. t_ENABLE SHIFT vs LDR RADIATION
0
0
10
20
30
40
50
60
LOW DOSE RATE RADIATION (krad(Si))
FIGURE 54. t_DISABLE SHIFT vs LDR RADIATION
Applications Information
Power-Up Considerations
The circuit is designed to be insensitive to any given power-up
sequence between V⁺, V^- and VREF, however, it is recommended
that all supplies power-up relatively close to each other.
Overvoltage Protection
The ISL73841SEH has overvoltage protection on both the input
as well as the output. On the output, the voltage is limited to a
diode past the rails. Each of the inputs has independent
overvoltage protection that works regardless of the switch being
selected. If a switch experiences an overvoltage condition
(3V to 4V) past the rail), the switch is turned off. As soon as the
voltage returns within the rails, the switch returns to normal
operation.
VREF and Logic Functionality
The VREF pin sets the logic threshold for the ISL73841SEH. The
range for VREF is between 4.5V and 5.5V with a nominal voltage
of 5V. The address pins and enable are compared against
roughly 30% of V_REF voltage (refer to Figure 55). With 5.0V on
V_REF, the switching point is set to around 1.4V. This switching
point allows for both 5V and 3.3V logic control.
A/EN
VREF
ISL73841SEH
400kΩ
200kΩ
To Decoder
FIGURE 55. SIMPLIFIED V_REF CIRCUITRY
ISL73841SEH vs ISL73840SEH
There is a 16-channel version of the ISL73841SEH available in a
28 Ld CDFP. In terms of performance specifications, the parts
are very similar in behavior. Apart from the apparent increase in
channel density, the ISL73841SEH does have slightly higher
output leakage compared to the ISL73840SEH due to having
more channels connected to the output. The supply current for
the ISL73841SEH is also a bit higher compared to the
ISL73840SEH (see Table 1 on page 3).
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FN8846.1
May 31, 2016