OPA189 Datasheet, PDF (17/34 Pages) Texas Instruments – Precision, 36-V, 14-MHz, MUX-Friendly Low-Noise, Rail-to-Rail Output, Zero-Drift Operational Amplifiers

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(2)
TVS
R_F
OPA189, OPA2189, OPA4189
SBOS830 – JUNE 2017
+V_S
+V
I_D
V_IN(1)
R_I
-In
(3)
R_S
+In
Op Amp
Core
-V
ESD Current-
Steering Diodes
Out
Edge-Triggered ESD
Absorption Circuit
R_L
-V_S
TVS⁽²⁾
(1) V_IN = +V_S + 500 mV.
(2) TVS: +V_S(max) > V_{TVSBR (min)} > +V_S.
(3) Suggested value is approximately 5 kΩ.
Figure 7. Equivalent Internal ESD Circuitry Relative to a Typical Circuit Application
8.3.7 MUX-Friendly Inputs
The OPAx189 features a proprietary input stage design that allows an input differential voltage to be applied
while maintaining high input impedance. Typically, high-voltage CMOS or bipolar-junction input amplifiers feature
anti-parallel diodes that protect input transistors from large V_GS voltages that may exceed the semiconductor
process maximum and permanently damage the device. Large V_GS voltages can be forced when applying a large
input step, switching between channels, or attempting to use the amplifier as a comparator.
OPAx189 solves these problems with a switched-input technique which prevents large input bias currents when
large differential voltages are applied. This solves many issues seen in switched or multiplexed applications,
where large disruptions to RC filtering networks are caused by fast switching between large potentials. OPAx189
offers outstanding settling performance due to these design innovations and built-in slew rate boost and wide
bandwidth. The OPAx189 can also be used as a comparator. Differential and common-mode Absolute Maximum
Ratings still apply relative to the power supplies.
Copyright © 2017, Texas Instruments Incorporated
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Product Folder Links: OPA189 OPA2189 OPA4189