MXA211
Ultra-precision op-amp with 50μV offset, 1μV/°C drift, and radiation tolerance for aerospace sensor interfaces.
Product Overview
Description
The MXA211 is an ultra-precision operational amplifier featuring extremely low offset voltage of 50μV and offset drift of 1μV/°C.
With excellent DC precision and radiation tolerance options, this op-amp is ideal for sensor signal conditioning in satellite and military systems.
The device includes rail-to-rail output, high open-loop gain, and is available in hermetic ceramic packages for harsh environments.
Product Series
MXA
Primary Application
Sensor signal conditioning
Key Features
- Ultra-low offset voltage 50μV
- Low offset drift 1μV/°C
- High open-loop gain 120dB
- Excellent CMRR 110dB
- Rail-to-rail output swing
- Radiation tolerance to 100krad(Si)
- Hermetic ceramic packages
- Extended temperature range
Specifications
| Offset Voltage | 50μV maximum |
|---|---|
| Offset Drift | 1μV/°C maximum |
| Bandwidth | 1MHz |
| Slew Rate | 0.5V/μs |
| Open-Loop Gain | 120dB |
| CMRR | 110dB |
| PSRR | 100dB |
| Input Bias Current | 10nA maximum |
| Radiation Tolerance | 100 krad(Si) optional |
| Temperature Range | -55°C to +125°C |
| Package | TO-99, CERDIP-8, SMD-0.5 |
Applications
Sensor signal conditioning
Sensor signal conditioning
Precision instrumentation
Electronic system design
Satellite sensor systems
Sensor signal conditioning
Test equipment
Electronic system design
Medical devices
Medical electronics
Industrial controls
Industrial automation and control
FAE Expert Insights
"The MXA211 is my first choice for precision sensor conditioning in aerospace applications. The 50μV offset and 1μV/°C drift are exceptional specifications for a radiation-tolerant op-amp. In a recent satellite design, we used this part to condition strain gauge signals for structural health monitoring. Over the 15-year mission life, the offset drift would contribute less than 15μV error - negligible compared to the mV-level signal. The high open-loop gain (120dB) ensures accurate closed-loop performance. For thermocouple applications, the low offset is critical since the signal levels are in microvolts. I've also used this part for current sensing with high-side shunts where common-mode rejection is important - the 110dB CMRR effectively rejects common-mode noise. One tip: for lowest noise, use the TO-99 metal can package which provides better shielding than plastic packages."
Exceptional precision op-amp for aerospace sensor conditioning
— Dr. Liu Yang, BeiLuo
Frequently Asked Questions
What makes MXA211 ultra-precision?
MXA211 achieves ultra-precision through several design techniques: 1) Chopper-stabilized architecture cancels offset voltage automatically. 2) Precision trimmed input transistors minimize initial offset. 3) Temperature-compensated design reduces drift to 1μV/°C. 4) Careful layout minimizes thermocouple effects. 5) High-quality manufacturing process with tight process control. The chopper stabilization works by continuously measuring and correcting offset, resulting in near-zero effective offset. This comes with a trade-off: the chopping action creates small output ripple and limits bandwidth to 1MHz. For DC and low-frequency precision applications, this is an excellent trade-off.
Use chopper-stabilized op-amps for DC precision. Bandwidth limited to 1MHz due to chopping.
How do I calculate gain for an inverting amplifier?
Inverting amplifier gain formula: Gain = -R_f / R_in. For example, with R_in = 10kΩ and R_f = 100kΩ, Gain = -100k/10k = -10. Output voltage: V_out = -Gain × V_in = -10 × V_in. Input impedance is approximately R_in (10kΩ). For DC precision, add compensation resistor R_comp = R_in || R_f from non-inverting input to ground to cancel bias current effects. For MXA211 with 10nA bias current and R_in || R_f = 9kΩ, offset is about 90μV. Bandwidth at gain of 10: BW = GBW / Gain = 1MHz / 10 = 100kHz. Use precision resistors (0.1% or better) for accurate gain.
Choose R_in based on input impedance requirements. Calculate R_f for desired gain. Add compensation resistor.
What is the impact of radiation on op-amp offset?
Radiation causes offset voltage shift in op-amps due to trapped charge in gate oxides and interface states. MXA211 radiation performance: Offset shift is typically <100μV at 100krad(Si). This is small compared to the 50μV initial offset. The offset shift is predictable and can be compensated in system calibration. For critical applications, use radiation-tolerant grade and account for end-of-life offset in error budget. Mxtronics provides radiation test data showing offset shift vs TID for each production lot. Single event effects can cause transient offset shifts, but these recover after the event.
Account for <100μV offset shift at 100krad in design. Use radiation test data for mission-critical applications.
How do I minimize noise in op-amp circuits?
Noise reduction techniques: 1) Use low-value resistors - thermal noise is proportional to √(R). Use 1kΩ instead of 100kΩ where possible. 2) Add bypass capacitors - 100nF ceramic close to supply pins. 3) Use guard rings around high-impedance nodes. 4) Keep traces short and away from digital signals. 5) Use differential signaling for long traces. 6) Add RC filtering at input if bandwidth allows. 7) Use star grounding. 8) Shield sensitive circuits. For MXA211, input voltage noise is 50nV/√Hz. With 1kHz bandwidth, noise is about 1.6μVrms. This is negligible for most applications.
Use low resistor values and proper bypassing. Shield and guard high-impedance nodes. Filter if bandwidth allows.
When should I use chopper-stabilized vs standard op-amp?
Use chopper-stabilized (like MXA211) when: DC precision is critical (offset <100μV required), measuring microvolt-level signals, long-term stability is important (minimal drift), low-frequency applications (<1kHz). Use standard op-amp when: Bandwidth >1MHz is needed, cost is critical, chopping ripple cannot be tolerated, high-speed settling required. Chopper op-amps have limited bandwidth (typically 1MHz) and produce small output ripple at chopping frequency. For AC-coupled applications, standard op-amps are usually sufficient. For DC instrumentation, chopper op-amps provide superior performance.
Use chopper for DC precision. Use standard for bandwidth or when chopping ripple is problematic.