Run-IC are glad to announce the release of the below product:

RS8491 is a femtoampere input bias current electrometer amplifier.

Cross P/N: ADA4530-1. Available package: SOIC-8. Applications include laboratory and analytical instrumentation, instruments, transimpedance amplifier.

RS8491 – Femtoampere Input Bias Current Electrometer Amplifier CMOS, Single-channel, High Accuracy

Feature

• Supply Voltage: 5V~25V (±2.5V~±12.5V)
• Supply Voltage： ±200fA(max)
• High accuracy:
✓ Input Offset Voltage: 54uV (typ)
✓ Vos Tc: ±5uV/℃ (typ)
✓ Noise: 14nV/√Hz @f=10KHz
• DC Characteristics：
✓ PSRR: 106dB
✓ CMRR: 102dB
✓ Open-Loop Voltage Gain: 130dB
• AC Characteristics :
✓ Gain-Bandwidth Product: 3.3MHz
✓ Slew Rate: 2.1V/µs
• Temperature Range: -40℃—125 ℃
• Package ： SOIC-8

Applications

• Laboratory and analytical instrumentation: spectrophotometers, chromatographs, mass spectrometers, and potentiostatic and amperostatic coulometry
• Instrumentation: picoammeters and coulombmeters
• Transimpedance Amplifier (TIA) for photodiodes, ion chambers, and working electrode measurements
• High Impedance Buffering for Chemical Sensors and Capacitive Sensors

Selling Point

• Excellent DC characteristics, high PSRR and CMRR improve the ability to resist power supply noise and common mode interference, and high open loop gain ensures high precision of the op amp.
• Rail-to-rail output design maximizes the dynamic range of the signal, and improve the overall signal-to-noise ratio of the signal chain.
• Wide power supply voltage range is suitable for a variety of application scenarios.
• The integrated guard buffer isolates the input pins from leakage in the printed circuit board (PCB), minimizes board component count, and enables easy system design.
• Available in SOIC-8 package.

RS8491 Femtoampere Input Bias Current Electrometer Amplifier

1 FEATURES

• Low Input Bias Current: – ±200fA (Max) at TA =25°C
• Low Offset Voltage: 54μV typical @5V supply
• Offset voltage drift: ±5μV/°C typical
• Integrated guard buffer with 400μV maximum offset
• Low voltage noise density: 14nV/√𝐇𝐳 at 10kHz
• Wide bandwidth: 3.3MHz unity-gain crossover
• Supply voltage: 5V to 25V (±2.5V to ±12.5V)
• Operating temperature: -40°C to +125°C
• Micro SIZE PACKAGES: SOIC-8(SOP8)

2 APPLICATIONS

• Laboratory and analytical instrumentation: spectrophotometers, chromatographs, mass spectrometers, and potentiostatic and amperostatic coulometry
• Instrumentation: picoammeters and coulombmeters
• Transimpedance Amplifier (TIA) for photodiodes, ion chambers, and working electrode measurements
• High Impedance Buffering for Chemical Sensors and Capacitive Sensors

3 DESCRIPTIONS

The RS8491 is a femtoampere (10−15A) level input bias current operational amplifier suitable for use as an electrometer that also includes an integrated guard buffer. It has an operating voltage range of 5V to 25V, enabling it to operate in conventional 5V and 25V single supply systems as well as ±2.5V and ±12.5V dual supply systems.

The integrated guard buffer isolates the input pins from leakage in the printed circuit board (PCB), minimizes board component count, and enables easy system design. The RS8491 is available in an industry standard surface-mount 8-lead SOIC package with a unique pinout optimized to prevent signals from coupling between the sensitive input pins, the power supplies, and the output pin while enabling easy routing of the guard ring traces.

The RS8491 also offers low offset voltage, low offset drift, and low voltage and current noise needed for the types of applications that require such low leakages. To maximize the dynamic range of the system, the RS8491 has a rail-to-rail output stage.

The RS8491 is available in Green SOIC-8(SOP8) packages. It operates over an ambient temperature range of -40°C to +125°C.