Tough precision op-amp blocks input abuse
The ADA4096-2 dual and ADA4096-4 quad operational amplifiers feature micropower operation and rail-to-rail input and output ranges. The extremely low power requirements and guaranteed operation from 3 V to 30 V make these amplifiers perfectly suited to monitor battery usage and to control battery charging. Their dynamic performance, including 27 nV/√Hz voltage noise density, recommends them for battery-powered audio applications. Capacitive loads to 200 pF are handled without oscillation.
The ADA4096-2 and ADA4096-4 have overvoltage protection inputs and diodes that allow the voltage input to extend 32 V above and below the supply rails, making this device ideal for robust industrial applications. The ADA4096-2 and ADA4096-4 feature a unique input stage that allows the input voltage to exceed either supply safely without any phase reversal or latch-up; this is called overvoltage protection, or OVP.
The dual ADA4096-2 is available in 8-lead LFCSP (2 mm × 2 mm) and 8 lead MSOP packages. The ADA4096-4 is available in 16-lead LFCSP (3 mm × 3 mm) and 14 lead TSSOP packages. The ADA4096-2W is qualified for automotive applications and is available in an 8-lead MSOP package.
- Battery monitoring
- Sensor conditioners
- Portable power supply control
- Portable instrumentation
FEATURES and BENEFITS
- Input overvoltage protection,
32 V above and below the supply rails
- No phase reversal for input voltage up to ±32 V beyond the power supply
- Rail-to-rail input and output swing
- Low power: 60 μA per
- Unity-gain bandwidth
800 kHz typ @ VSY = ±15 V
550 kHz typ @ VSY = ±5 V
465 kHz typ @ VSY = ±1.5 V
Analog Devices has announced a precision micro-power op amp that can handle inputs well outside the supply voltage rails.
The inputs of chip, dubbed ADA4096-2, will survive 32V on top of the +ve rail and 32V below the negative rail.
“It is the industry’s first precision op amp with more than +/-30V of integrated input over-voltage protection,” said ADI. “Over-voltage protection operates without damage, glitching, or phase reversal, and since op amps can be damaged if the signal they are monitoring is live when its power supplies are not available, the protection was designed to remain active even when power is not applied.”
Specified to operate from a 3-30V supply over -40 to 125°C, the device draws 60µA per amplifier “and features twice the bandwidth and half the voltage noise of its competitors”, claimed the firm.
Unity gain bandwidth is 800kHz at 30V, 550kHz at 10V and 475kHz at 3V with 27nV?Hz noise.
Precision credentials are derived from the 35µV typical input offset voltage, which degrades to 400µV max over voltage and temperature, and typical drift of 1µV/°C.
Open loop gain is typically 125dB, and the amplifiers are unity-gain stable.
For more read: Tough precision op-amp blocks input abuse