Analog Devices Inc. MAX74840 JFET Operational Amplifiers
Analog Devices MAX74840 JFET Operational Amplifiers (Op Amps) are high‑performance, single‑supply op amps designed for precision signal conditioning in demanding analog applications. Built with a junction field effect transistor (JFET) input stage, the ADI MAX74840 offers extremely low input bias current (typically in the picoampere range), well-suited for interfacing with high‑impedance sensors such as photodiodes and other current‑based sources. The device operates from a wide supply voltage range of 5V to 30V and features a rail‑to‑rail output (RRO) stage, allowing it to maximize dynamic signal range in single‑supply systems without the need for a negative supply rail.
With an 8MHz gain‑bandwidth product and a high slew rate of up to 23V/µs, this op amp delivers fast settling and accurate signal reproduction, even when driving the inputs of modern successive‑approximation‑register (SAR) analog-to-digital converters (ADCs). Integrated input EMI filtering provides strong immunity to high‑frequency interference, improving robustness in electrically noisy environments. These characteristics make the ADI MAX74840 an excellent choice for precision filters, transimpedance amplifiers, ADC drivers, and general signal conditioning applications that require low noise, low bias current, and wide operating voltage capability across an extended industrial temperature range.
Features
- Wide 8MHz (typical) gain bandwidth product
- High slew rate
- 23V/µs typical (low to high)
- -18V/µs typical (high to low)
- Low ±15pA (maximum) input bias current at TA = +25°C
- Low ±10mV (maximum) offset voltage at TA = +25°C
- Low ±4µV/°C (typical) offset voltage drift
- Input voltage range includes Pin V-
- Rail-to-rail output
- 90dB typical electromagnetic interference rejection ratio (EMIRR) at f = 1000MHz and f = 2400MHz
- RoHS-compliant
Applications
- High-output impedance sensor interfaces
- Photodiode sensor interfaces
- Transimpedance amplifiers
- Analog-to-digital converter (ADC) drivers
- Precision filters and signal conditioning
Specifications
- 36V maximum supply voltage
- 36V maximum differential input voltage
- Maximum input current
- ±10mA indefinite
- ±100mA at <1s duration
- Input
- ±10mV maximum offset voltage
- ±1mV maximum offset voltage match
- ±4µV/°C typical offset voltage drift
- ±15pA maximum input bias current
- ±15pA maximum input offset current
- -15.2V to 14V input voltage range
- 81dB to 98dB typical common-mode rejection ratio range
- 109dB to 122dB typical open-loop voltage gain range
- Typical input capacitance
- 0.4pF in differential mode
- 3.6pF in common mode
- 1013Ω typical input resistance
- Output
- 20mA typical output current
- Typical short-circuit current
- 42mA sourcing
- -51mA sinking
- 0.1Ω to 3Ω typical closed-loop output impedance range
- Power supply
- 81dB to 100dB typical power supply rejection ratio range
- 1.05mA maximum supply current per amplifier
- 90dB typical EMI rejection ratio
- Dynamic performance
- -18V/µs to 23V/µs typical slew rate range
- 8MHz typical gain bandwidth
- 7MHz typical unity-gain crossover
- 15.5MHz -3dB bandwidth
- 53° typical phase margin
- Typical settling time
- 1.5µs settling time to 0.1%
- 2µs settling time to 0.01%
- Noise performance
- 0.75µVp-p typical voltage noise
- 12nV/√Hz to 30nV/√Hz typical voltage noise density range
- 0.8fA/√Hz typical current noise density
- Typical total harmonic distortion plus noise
- 0.0003% at BW = 80kHz
- 0.00035% at BW = 500kHz
- Matching
- 0.5mV (typical) maximum offset voltage over temperature
- 0.25µV/°C typical offset voltage temperature drift
- 5p maximum input bias current, 0.5pA typical
- Typical crosstalk
- -112dB at f = 1kHz
- -72dB at f = 100kHz
- Indefinite output short-circuit duration to GND
- -40°C to +125°C operating temperature range
- -65°C to +150°C junction temperature range
- +300°C maximum lead soldering temperature for 10s
- 4kV maximum Human Body Model (HBM) ESD rating
Simplified Circuit Diagram
