OPA196 Datasheet, PDF (19/47 Pages) Texas Instruments – 36-V, Low-Power, Low Offset Voltage, Rail-to-Rail Operational Amplifier

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OPA196, OPA2196, OPA4196
SBOS869 – JULY 2017
7.3 Feature Description
7.3.1 Input Protection Circuitry
The OPAx196 uses a unique input architecture to eliminate the need for input protection diodes but still provides
robust input protection under transient conditions. Conventional input diode protection schemes shown in
Figure 36 can be activated by fast transient step responses and can introduce signal distortion and settling time
delays because of alternate current paths, as shown in Figure 37. For low-gain circuits, these fast-ramping input
signals forward-bias back-to-back diodes that cause an increase in input current, resulting in extended settling
time.
V+
V+
VIN+
VIN
36 V
OPAx196
VOUT
VIN+
VIN
~0.7 V
VOUT
V
OPAx196 Provides Full 36-
V Differential Input Range
V
Conventional Input Protection
Limits Differential Input Range
Figure 36. OPA196 Input Protection Does Not Limit Differential Input Capability
Vn = +10 V R_FILT
+10 V
C_FILT
Vn+1 = ±10 V R_FILT
±10 V
C_FILT
Input Low Pass Filter
S_n
C_S
R_{on_mux}
1
D
1
2
+10 V
~±9.3 V
C_D
S_n+1
R_{on_mux}
2
Vin±
C_S
I_{diode_transient}
Simplified Mux Model
~0.7 V
Vout
Vin+
±10 V
Buffer Amplifier
Figure 37. Back-to-Back Diodes Create Settling Issues
The OPAx196 family of operational amplifiers provides a true high-impedance differential input capability for high-
voltage applications. This patented input protection architecture does not introduce additional signal distortion or
delayed settling time, making the device an optimal op amp for multichannel, high-switched, input applications.
The OPA196 can tolerate a maximum differential swing (voltage between inverting and noninverting pins of the
op amp) of up to 36 V, making the device suitable for use as a comparator or in applications with fast-ramping
input signals such as multiplexed data-acquisition systems (see Figure 49).
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Product Folder Links: OPA196 OPA2196 OPA4196