TYPICAL PERFORMANCE CURVES (CONT)
TCASE = +25°C, VS = ±150V, unless otherwise noted.
MAXIMUM COMMON-MODE VOLTAGE
vs FREQUENCY
POWER SUPPLY REJECTION vs FREQUENCY
120
100
80
150
125
100
75
Compensation: 200Ω and 0.01µF
60
Positive Supply
Negative Supply
40
50
20
0
25
0
10
100
1k
10k
100k
1M
10k
100k
1M
Frequency (Hz)
Frequency (Hz)
APPLICATION INFORMATION
Figure 1 shows the basic connections required to operate the
3584. Bypass capacitors should be connected close to the
device pins. Be sure that these capacitors have an adequate
voltage rating.
The thermal shut-down circuit will normally protect the
amplifier during a short-circuit to ground. It will not protect
against short-circuit to one of the power supplies. The
typical performance curve “Safe Operating Area” shows that
the large stress occurring during this high voltage condition
may cause damage if it exceeds 5ms duration. The thermal
protection circuitry will not activate fast enough to protect
the device from short-circuits to one of the power supplies.
Frequency compensation components must be connected to
pin 8 for closed-loop gains of 100 or less. Recommended
values are shown in Figure 1. Some adjustment in these
values may be required depending on exact circuit configu-
ration and load conditions. Be sure the compensation capaci-
tor has a voltage rating equal to or greater than the positive
power supply voltage, V+. Standard 0.25W resistors can be
used for RC.
The package case of the 3584 is electrically isolated from all
circuitry. No special insulating hardware is required. Al-
though not absolutely required, it is recommended that the
case be connected to ground.
Input offset voltage and drift of the 3584 are laser-trimmed.
Many applications require no external offset trimming.
Figure 1 shows connection of an optional offset trim poten-
tiometer which connects to pins 3 and 4.
V+
Optional offset
voltage trim
FET input circuitry reduces the input bias current of the
3584 to less than 20pA at room temperature. Input bias
current remains nearly constant throughout the full com-
mon-mode range. Input bias current approximately doubles
for each 10°C increase in case temperature above 25°C.
Heat sinking can help minimize this effect by reducing the
case temperature.
+70V to +150V
V+
4
100kΩ
circuit.
3
3584
0.1µF
R1
R2
R2
G = 1 +
VO
R1
Input circuitry of the 3584 is protected with series limiting
resistors and input clamp diodes. The inputs can withstand
the full rated supply voltage of ±150V (common-mode or
differential).
5
6
2
1
3584
8
VIN
7
RC
CC
Gain
CC
RC
0.1µF
1
10
10nF
500pF
50pF
200Ω
2kΩ
20kΩ
Connect case
to ground.
THERMAL PROTECTION
100
1000 (no connection)
V–
–70V to –150V
The 3584 has internal thermal shut-down circuitry that
activates at a case temperature of approximately 150°C or
higher. As this circuitry is activated, the output current drive
is reduced. As the case temperature returns to less than the
activation temperature, operation will return to normal.
Interpolate values for
intermediate gains.
FIGURE 1. Basic Circuit Connections.
®
5
3584