ADA4530-1 Femtoampere Input Bias Current Electrometer Amplifier

The ADA4530-1 is a femtoampere (10−15 A) 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 4.5 V to 16 V enabling it to operate in conventional 5 V and 10 V single supply systems as well as ±2.5 V and ±5 V dual supply systems.

It provides ultralow input bias currents that are production tested at temperature to ensure the device meets its performance goals in user systems. The integrated guard buffer is provided to isolate the input pins from leakage in the printed circuit board (PCB), minimize board component count, and enable ease of system design. The ADA4530-1 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 ADA4530-1 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 ADA4530-1 has a rail-to-rail output stage that can typically drive to within 30 mV of the supply rails under a 10 kΩ load.

The ADA4530-1 operates over the −40°C to +125°C industrial temperature range and is available in an 8-lead SOIC package.

Applications

Laboratory and analytical instrumentation: spectrophotometers, chromatographs, mass spectrometers, potentiostatic and amperostatic coulometry
Instrumentation: picoammeters, coulombmeters
Transimpedance amplifier (TIA) for photodiodes, ion chambers, and working electrode measurements
High impedance buffering for chemical sensors and capacitive sensors

Features and Benefits

Low input bias current

±20 fA maximum at TA = 25°C (guaranteed at production test)

±20 fA maximum at −40°C < TA < +85°C

±250 fA maximum at −40°C < TA < +125°C (guaranteed at production test)

Low offset voltage: 50 μV maximum over specified CMRR range

Offset drift: 0.13 μV/°C typical, 0.5 μV/°C maximum

Integrated guard buffer with 100 μV maximum offset

Low voltage noise density: 14 nV/√Hz at 10 kHz

Wide bandwidth: 2 MHz unity-gain crossover

Supply voltage: 4.5 V to 16 V (±2.25 V to ±8 V)

Operating temperature: −40°C to +125°C

Amplifiers

Operational Amplifiers (Op Amps)

Instrumentation and Measurement

Chemical Analysis

SPICE Models

ADA4530 SPICE Macro-Model .CIR

Data Sheets

Document	note
ADA4530-1: Femtoampere Input Bias Current Electrometer Amplifier Data Sheet (Rev. A)	PDF 1.86 M

Application Notes

Document	note
AN-1373: ADA4530-1 Femtoampere Level Input Bias Current Measurement (Rev. 0)	PDF 599.79 K

User Guides

Document	note
UG-865: ADA4530-1 8-Lead SOIC Package Evaluation Board (Rev. 0)	PDF 603.3 K

Order Information

Part Number	Package	Packing Qty	Temp Range	Price 100-499	Price 1000+	RoHS
ADA4530-1ARZ Production	8 ld SOIC	OTH 98	-40 to 125C	15	11.4	Y
ADA4530-1ARZ-R7 Production	8 ld SOIC	REEL 1000	-40 to 125C	0	11.4	Y
ADA4530-1ARZ-RL Production	8 ld SOIC	REEL 2500	-40 to 125C	0	11.4	Y