OPA837 Voltage-Feedback Operational
Amplifiers
• Bandwidth: 105MHz (AV = 1V/V)
• Very Low (Trimmed) Supply Current: 600µA
• Gain Bandwidth Product: 50MHz
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input of the op-amp when large voltage steps are applied. This
protection scheme has the added benefit of no inrush current.
Figure 4 shows this new MUX-friendly protection scheme in its
quiescent state. Notice that both switches are closed and the
diodes are inactive.
When the positive input goes low (10V to –10V), the control
block opens the switch at the inverting terminal (IN-) and
activates one of the diodes, illustrated in Figure 5. When the
positive input goes high (–10V to 10V), the control block opens
the switch at the non- inverting terminal (IN+) and activates the
other diode.
The internal buffer op-amp, labeled "B", isolates the diode
current from the input signal. This prevents current from flowing
through the input pins of the op-amp. This new MUX-friendly
architecture prevents any additional settling time—this means
systems can quickly switch between MUX channels without
compromising precision.
Additional Resources
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Table 1: TI MUX-Friendly Amplifiers
Figure 4: MUX-Friendly Scheme
Figure 5: High to Low Input Step
Device Optimized Parameters
OPA191
CMOS input 25µV offset max, 0.8µV/°C drift max,
2.5MHz, 200µA supply current max
OPA192
CMOS input 25µV offset max, 0.5µV/°C drift max,
10MHz, 1.2mA supply current max
OPA189
CMOS input 2.5µV offset max, 0.02µV/°C drift typ,
14MHz, 1.7mA supply current max
OPA145
JFET input 150µV offset max, 1µV/°C drift typ, 5.5MHz,
475µA supply current max
OPA827
JFET input 150µV offset max, 2µV/°C drift typ, 22MHz,
5.2mA supply current max
