Analog Devices Inc. ADA4530-1 Amplifiers
Analog Devices ADA4530-1 femtoampere-level (10-15 A) input-bias current electrometer amplifiers are suitable for use as an electrometer with an integrated guard buffer. The integrated guard buffers are designed to do the following.
- Isolate the input pins from leakage in the printed circuit board (PCB)
- Minimize board component count
- Enable ease of system design
The ADA4530-1 amplifiers have a 4.5V to 16V operating voltage range. The voltage range allows the amplifiers to operate in conventional 5V and 10V single-supply systems as well as ±2.5V and ±5V dual supply systems.
The devices provide ultra-low input bias currents of ±20fA at TA = 25°C, the low offset voltage of 50μV maximum over specified CMRR range, low offset drift of 0.13μV/°C (typical), and low voltage noise density of 14nV/√Hz at 10kHz. To maximize the dynamic range of the system, the ADA4530-1 amplifiers have a rail-to-rail output stage that can typically drive to within 30mV of the supply rails under a 10 kΩ load.
The ADA4530-1 amplifiers are available in an industry-standard surface-mount 8-lead SOIC package with a unique pinout optimized to prevent signals from the coupling between the sensitive input pins, the power supplies, and the output pin while enabling easy routing of the guard ring traces.
Features
- Low offset voltage: 50μV maximum over specified CMRR range
- Offset drift: 0.13μV/°C typical, 0.5μV/°C maximum
- Integrated guard buffer with 100μV maximum offset
- Low voltage noise density: 14nV/√Hz at 10kHz
- Wide bandwidth: 2MHz unity-gain crossover
- Supply voltage: 4.5V to 16V (±2.25V to ±8V)
- Operating temperature: −40°C to +125°C
Simplified Schematic
Pin Connection Diagram
