MAX366 Maxim, MAX366 Datasheet - Page 10

• Manufacturer Part Number: MAX366
• Description: Signal-Line Circuit Protectors
• Manufacturer: Maxim

Signal-Line Circuit Protectors
These devices are not high-voltage arresters, nor are they
substitutes for surge suppressers. In systems that use
these forms of protection, however, the MAX366/MAX367
can fill a vital gap. Figure 7 shows a typical circuit.
Although the surge suppressers are extremely fast shunt
elements, they have very soft current knees. Their clamp
voltage must be chosen well above the normal signal
levels, because they have excessive leakage currents as
the knee is approached. This current can interfere with
normal operation when signal levels are low or imped-
ances are high. If the clamp voltage is too high, however,
the input can be damaged.
Using a MAX366/MAX367 after the surge suppresser
allows the surge-suppresser voltage to be set above
the supply voltage (but within the overvoltage limits),
dramatically reducing the effects of leakage (Figure 7).
During a surge, the surge suppresser clamps the input
voltage to roughly ±10V.
MAX366/MAX367, but the MAX366/MAX367 still dis-
connect the signal from the op amp well within the ±5V
supply.
10
_________________Pin Configurations
__High-Voltage Surge Suppression
IN1
IN2
IN3
V-
______________________________________________________________________________________
TOP VIEW
1
2
3
4
DIP/SO
MAX366
8
7
6
5
V+
OUT1
OUT2
OUT3
IN1
IN2
IN3
IN4
IN5
IN6
IN7
IN8
V-
1
2
3
4
5
6
7
8
9
This protects the
DIP/SO
MAX367
18
17
16
15
14
12
11
10
13
V+
OUT1
OUT4
OUT5
OUT7
OUT8
OUT2
OUT3
OUT6
Figure 7. Surge-Suppression Circuit
TRANSISTOR COUNT: 21
SUBSTRATE CONNECTED TO V+
___________________Chip Topography
IN2
IN1
IN3
V-
SURGE SUPPRESSERS
(+10V)
1
2
3
4
(2.16mm)
IN1
IN2
IN3
V-
0.085"
MAX366
OUT1
OUT2
OUT3
V+
7
6
5
8
V+
OUT1
OUT2
OUT3
OP AMP
+5V
-5V
(2.84mm)
0.112"