POWER AND LINEAR IC SOLUTIONS

Precision Amp Extends Battery Life in Portable Applications

The AD8500 precision operational amplifier from Analog Devices reduces power consumption by 30% and enables higher accuracy in battery-powered consumer, medical and safety devices. Optimised to meet the power, voltage, accuracy and price requirements of portable battery-powered applications, the device operates from a low 1.8V supply voltage without sacrificing precision performance.


Low-Power, Low-Voltage Precision Amplifier

Priced to meet the needs of high-volume markets, the AD8500 op-amp provides longer continuous battery life in portable precision sensing applications such as smoke detectors, glucose monitors and remote sensors. To satisfy the size constraints for such equipment, it is supplied in a tiny surface mount package.

The AD8500 is a precision CMOS device that draws a maximum supply current of 1µA. It operates from a single supply voltage of +1.8V to +5.5V or a dual supply voltage of ±0.9V to ±2.75V. The low voltage allows the use of the device with two-cell batteries over the full discharge profile, thus extending battery lifetime.

The amplifier features exceptional offset performance of 1mV maximum, allowing it to be used in high-gain systems without output offset errors, and to achieve high accuracy without the need for system calibration. It requires a low input bias current of 1pA. Its ability to swing rail-to-rail at both the input and output helps to maximise dynamic range and Signal-to-Noise Ratio (SNR) in low-voltage systems.

To minimise power consumption and improve signal chain performance, the AD8500 can be used with Analog Devices' low-power precision Analogue-to-Digital Converters (ADCs), such as the AD7788. The device is housed in a five-lead SC-70 package, and is fully specified over the industrial temperature range of –40°C to +85°C.

Features

• Low-voltage precision op-amp
• Voltage offset 1mV maximum
• No phase reversal
• Unity-gain stable
• Low noise: 190nV/√Hz voltage noise density at 1kHz
• Low input bias current: 1pA
• Swings rail-to-rail at both input and output
• Maximum supply current 1µA
• Single +1.8V to +5.5V or dual ±0.9V to ±2.75V supply voltage
• Five-lead SC-70 package
• Industrial temperature range: –40°C to +85°C

Applications:

• Battery-powered consumer, medical and safety
  • Electrocardiograms (ECGs)
  • Pulse monitors
  • Glucose meters
  • Smoke, fire and gas detectors
  • Security systems
  • Backup battery sensors
  • Insulin pumps
  • UltraViolet radiation (UV) detectors in cellular handsets

For further information, including Analog Devices Shortform and AD8500 Datasheet, please click here