ISL70227SEHF INTERSIL [Intersil Corporation], ISL70227SEHF Datasheet - Page 14

• Manufacturer Part Number: ISL70227SEHF
• Description: 36V Rad Hard Dual Precision Operational Amplifier
• Manufacturer: INTERSIL [Intersil Corporation]

Applications Information
Functional Description
The ISL70227SEH is a dual, low noise 10MHz BW precision
op amp fabricated in a new precision 40V complementary
bipolar DI process. A super-beta NPN input stage with input bias
current cancellation provides low input bias current (1nA typical),
low input offset voltage (10µV typ), low input noise voltage
(3nV/√Hz), and low 1/f noise corner frequency (5Hz). These
amplifiers also feature high open loop gain (1500V/mV) for
excellent CMRR (120dB) and THD+N performance (0.0002% @
3.5V
enables high capacitive load drive without external
compensation.
Operating Voltage Range
The devices are designed to operate over the 4.5V (±2.25V) to
36V (±18V) range and are fully characterized at 30V (±15V).
Parameter variation with operating voltage is shown in the
“Typical Performance Curves” beginning on page 9.
Input ESD Diode Protection
The input terminals (IN+ and IN-) have internal ESD protection
diodes to the positive and negative supply rails, and an additional
anti-parallel diode pair across the inputs (see Figures 37 and 38).
For unity gain applications (see Figure 37) where the output is
connected directly to the non-inverting input a current limiting
resistor (R
protect the anti-parallel differential input protection diodes.
• The amplifier input is supplied from a low impedance source.
• The input voltage rate-of-rise (dV/dt) exceeds the maximum
If the output lags far enough behind the input, the anti-parallel
input diodes can conduct. For example, if an input pulse ramps
from 0V to +10V in 1µs, then the output of the ISL70227SEH will
reach only +3.6V (slew rate = 3.6V/µs) while the input is at 10V,
The input differential voltage of 6.4V will force input ESD diodes to
conduct, dumping the input current directly into the output stage
and the load. The resulting current flow can cause permanent
damage to the ESD diodes. The ESD diodes are rated to 20mA,
and in the previous example, setting R
Figure 37) would limit the current to <6.4mA, and provide
additional protection up to ±20V at the input.
In applications where one or both amplifier input terminals are at
risk of exposure to high voltage, current limiting resistors may be
needed at each input terminal (see Figure 38 R
current through the power supply ESD diodes to 20mA.
FIGURE 37. INPUT ESD DIODE CURRENT LIMITING - UNITY GAIN
slew rate of the amplifier (±3.6V/µs).
RMS
V
, 1kHz into 2kΩ). A complimentary bipolar output stage
IN
IN
) will be needed under the following conditions to
R
IN
-
+
14
V+
V-
IN
to 1k resistor (see
R
L
IN
+, R
IN
V
ISL70227SEH
-) to limit
OUT
Output Current Limiting
The output current is internally limited to approximately ±45mA
at +25°C and can withstand a short circuit to either rail as long
as the power dissipation limits are not exceeded. This applies to
only one amplifier at a time. Continuous operation under these
conditions may degrade long term reliability.
Output Phase Reversal
Output phase reversal is a change of polarity in the amplifier
transfer function when the input voltage exceeds the supply
voltage. The ISL70227SEH are immune to output phase reversal,
even when the input voltage is 1V beyond the supplies.
Power Dissipation
It is possible to exceed the +150°C maximum junction
temperatures under certain load and power supply conditions. It
is therefore important to calculate the maximum junction
temperature (T
supply voltages, load conditions, or package type need to be
modified to remain in the safe operating area. These parameters
are related using Equation 1:
where:
• P
• PD
where:
• T
• θ
• PD
• V
• I
• V
• R
T
PD
JMAX
FIGURE 38. INPUT ESD DIODE CURRENT LIMITING - DIFFERENTIAL
each amplifier in the package (PD
qMAX
MAX
V
MAX
JA
S
OUTMAX
DMAXTOTAL
L
V
IN
IN
MAX
MAX
= Total supply voltage
= Load resistance
+
= Thermal resistance of the package
-
=
= Maximum ambient temperature
=
= Maximum quiescent supply current of one amplifier
T
for each amplifier can be calculated using Equation 2:
= Maximum power dissipation of one amplifier
V
MAX
= Maximum output voltage swing of the application
S
×
R
R
INPUT
is the sum of the maximum power dissipation of
+
I
JMAX
IN
IN
qMAX
θ
+
-
JA
) for all applications to determine if power
xPD
+
-
+
(
V
MAXTOTAL
S
- V
OUTMAX
V+
V-
MAX
)
×
V
------------------------
)
OUTMAX
R
L
R
L
August 24, 2012
V
OUT
FN7958.1
(EQ. 2)
(EQ. 1)