PGA855 Low-Noise, Wide-Bandwidth, Fully Differential Output Programmable-Gain

Instrumentation Amplifier

1 Features

• Eight pin-programmable binary gains

– G (V/V) = ⅛, ¼, ½, 1, 2, 4, 8, and 16

• Low gain error drift: 2 ppm/°C (max)

• Fully differential outputs

– Independent output power-supply pins

– Output common-mode control

• Faster signal processing:

– Wide bandwidth: 10 MHz at all gains

– High slew rate: 35 V/µs

– Settling time:

500 ns to 0.01%, 950 ns to 0.0015%

– Input stage noise: 7.8 nV/√Hz at G = 16 V/V

– Filter option to achieve better SNR

• Input overvoltage protection to ±40 V beyond

supplies

• Input-stage supply range:

– Single supply: 8 V to 36 V

– Dual supply: ±4 V to ±18 V

• Output-stage supply range:

– Single supply: 4.5 V to 36 V

– Dual supply: ±2.25 V to ±18 V

• Specified temperature range: –40°C to +125°C

• Small package: 3-mm × 3-mm QFN

2 Applications

• Factory automation and control

• Analog input module

• Data acquisition (DAQ)

• Test and measurement

• Semiconductor test

3 Description

The PGA855 is a high-bandwidth programmable

gain instrumentation amplifier with fully differential

outputs. The PGA855 is equipped with eight binary

gain settings, from an attenuating gain of 0.125 V/V

to a maximum of 16 V/V, using three digital gain

selection pins. The output common-mode voltage can

be independently set using the VOCM pin.

The PGA855 architecture is optimized to drive

inputs of high-resolution, precision analog-to-digital

converters (ADCs) with sampling rates up to 1 MSPS

without the need for an additional ADC driver. The

output-stage power supplies are decoupled from the

input stage to protect the ADC or downstream device

against overdrive damage.

The super-beta input transistors offer an impressively

low input bias current, which in turn provides a

very low input current noise density of 0.3 pA/√Hz,

making the PGA855 a versatile choice for virtually

any sensor type. The low-noise current-feedback

front-end architecture offers excellent gain flatness

even at high frequencies, making the PGA855 an

excellent high-impedance sensor readout device.

Integrated protection circuitry on the input pins

handles overvoltages up to ±40 V beyond the power-

supply voltages.

Package Information

PART NUMBER

PACKAGE(1)

BODY SIZE (NOM)

PGA855

RGT (VQFN, 16)

3.00 mm × 3.00 mm

(1)

For all available packages, see the package option

addendum at the end of the data sheet.

+

–

OUT+

IN

IN+

OUT

ADC

INP

INN

FDA_IN

FDA_IN+

PGA855

+

–

VIN+

VIN

VOCM

+

VO

Gain

Network

A<2:0>

DGND

OVP

OVP

VS-

VS+

LVDD

LVSS

5 V

VDD

VSS

R

R

R

R

PGA855 Simplified Application

Frequency (Hz)

-80

-60

-40

-20

0

20

40

10

100

1k

10k

100k

1M

10M

G = 0.125

G = 0.25

G = 0.5

G = 1

G = 2

G = 4

G = 8

G = 16

Gain vs Frequency

PGA855

SBOSAE0 – APRIL 2023

An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,

intellectual property matters and other important disclaimers. ADVANCE INFORMATION for preproduction products; subject to change

without notice.