AD8639ARZ

The AD8638/AD8639 are single and dual wide bandwidth, auto-zero amplifiers featuring rail-to-rail output swing and low noise. These amplifiers have very low offset, drift, and bias current. Operation is fully specified from 5V to 16V single supply (±2.5V to ±8V dual supply). The AD8638/AD8639 provide benefits previously found only in expensive zero-drift or chopper-stabilized amplifiers. Using the Analog Devices topology, these auto-zero amplifiers combine low cost with high accuracy and low noise. No external capacitors are required. In addition, the AD8638/AD8639 greatly reduce the digital switching noise found in most chopper-stabilized amplifiers. With a typical offset voltage of only 3μV, drift of 0.01μV/°C, and noise of 1.2μV p-p (0.1Hz to 10Hz), the AD8638/AD8639 are suited for applications in which error sources cannot be tolerated. Position and pressure sensors, medical equipment, and strain gage amplifiers benefit greatly from nearly zero drift over their operating temperature ranges. Many systems can take advantage of the rail-to-rail output swing provided by the AD8638/AD8639 to maximize signal-to-noise ratio (SNR).

Applications

• Pressure and position sensors
• Strain gage amplifiers
• Medical instrumentation
• Thermocouple amplifiers
• Automotive sensors
• Precision references
• Precision current sensing

Key features

• Low offset voltage: 9μV maximum
• Offset drift: 0.04μV/°C maximum
• Rail-to-rail output swing
• 5V to 16V single-supply or +2.5V to +8V dual-supply operation
• High gain: 136 dB typical
• High CMRR: 133 dB typical
• High PSRR: 143 dB typical
• Very low input bias current: 40 pA maximum
• Low supply current: 1.3 mA maximum
• AD8639: qualified for automotive applications