Data Sheet

ADA4351-2

Compact, Dual-Channel, Precision, Programmable Gain Transimpedance Amplifier

(PGTIA)

Rev. 0

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FEATURES

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Small, dual-channel, complete PGTIA and AFE solution

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Small size package:16-lead LFCSP, 3 mm × 3 mm

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Integrated switches, 2 external gains per channel

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Wide input current dynamic range from picoamps to milliamps

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Excellent DC precision

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Low offset voltage: ±100 μV maximum, 25°C

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Low offset voltage drift: ±0.85 μV/°C maximum, −40°C to

+125°C

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Low input bias current: ±9 pA maximum, 25°C

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Low switch off leakage current : ±90 pA maximum (−40°C to

+125°C)

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New integrated architecture eliminates gain error due to switch

resistance

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Single-supply operation: +2.7 V to +5.5 V (dual-supply operation:

±1.85 V to ±2.75 V)

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Wide gain bandwidth product: 8.5 MHz

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Wide operating temperature range: −40°C to +125°C

APPLICATIONS

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Precision current to voltage (I to V) conversion

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Programmable gain TIAs

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Photodetector interface and amplification

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Optical networking equipment

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Optical power measurement

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Instrumentation—spectroscopy and chromatography

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Precision data acquisition systems (DAQ)

TYPICAL APPLICATION DIAGRAM

Figure 1. Compact Optical Measurement Signal Chain

GENERAL DESCRIPTION

The ADA4351-2 is a compact, monolithic, dual-channel, preci-

sion, programmable gain transimpedance amplifier (PGTIA). The

ADA4351-2 is a breakthrough solution for precisely measuring

small currents over a wide dynamic range. The precision of the

ADA4351-2 over a wide temperature range of −40°C to +125°C

enables users to perform one calibration of the end equipment

at room temperature, thereby saving test time and cost. The

ADA4351-2 integrates two low off leakage current switches per

channel, and the gain is programmable using two user-selectable

external resistors to provide a flexible, fully functional compact

PGTIA solution. Separate analog and digital supplies allow the

amplifier of the ADA4351-2 to operate on bipolar supplies, while

the integrated logic level shifting allows the digital interface to

remain ground referenced. Additionally, with its robust output stage

and low noise, the ADA4351-2 can directly drive 16-bit precision

analog-to-digital converters (ADCs, such as AD4696), providing a

complete analog front-end (AFE) to address the most challenging

precision current measurement applications.

The ADA4351-2 is offered in a 3 mm × 3 mm LFCSP, reducing

the printed circuit board (PCB) area by up to 70% relative to a

discrete design using standalone operational amplifiers (op amps)

and switches. Additionally, there is no exposed pad (EPAD) on the

back side of the LFCSP, eliminating the need for vias and allowing

routing on all layers of the PCB beneath the device to further

reduce the board area and to provide the most compact PGTIA and

AFE solution.

Figure 2. PGTIA Maximum Error RTI vs. Temperature (Includes Input Bias

Current (IB), Offset Voltage (VOS,) and Switch Off Leakage Current (IOFF))