Analog Devices Inc. AD8220BRMZ

Overview

AD8220BRMZ from Analog Devices is a JFET-input instrumentation amplifier in an 8-lead MSOP package, delivering rail-to-rail output swing, 10 pA max input bias current (B grade), 100 dB min CMRR at G = 10, and 1.5 MHz bandwidth at unity gain. It operates from 4.5 V to 36 V single supply or ±2.25 V to ±18 V dual supply, serving precision transducer signal conditioning in medical and industrial data acquisition systems.

For engineers reviewing the AD8220BRMZ datasheet, AD8220BRMZ pinout, AD8220BRMZ application, or AD8220BRMZ equivalent, key selection considerations include its ultra-low input bias current, gain-set-by-resistor architecture (G = 1 to 1000), rail-to-rail output on low-voltage supplies, −40°C to +85°C industrial temperature rating (B grade), and 4 kV HBM ESD protection.

Technical Context

The AD8220BRMZ uses a three-op-amp JFET-input topology with true differential inputs, enabling high common-mode rejection independent of source imbalance. Its gain is set externally via a single resistor across RG pins, directly scaling CMRR-higher gains yield higher CMRR (e.g., 100 dB min at G = 10).

It features a rail-to-rail output stage optimized for dynamic range on 5 V single supplies, input voltage range extending 0.1 V below negative rail, and reference pin (REF) for precise output level-shifting-critical when interfacing with unipolar ADCs requiring offset adjustment.

Key Specifications

Pinout & Package

The AD8220BRMZ is housed in an 8-lead MSOP package (3.0 mm × 3.0 mm, 0.65 mm pitch), occupying ~50% board area of standard SOIC-8.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar instrumentation amplifier applications.

Compared with AD8421ARMZ and INA128UA, the AD8220BRMZ uniquely combines JFET-input ultra-low bias current, rail-to-rail output on 5 V, and single-resistor gain programming-making it optimal for portable, low-power, high-precision sensor interfaces where board space and supply count are constrained.

Availability

AD8220BRMZ is available at Aetrix Electronics and suitable for medical instrumentation, precision data acquisition, transducer interfaces, and industrial sensor signal chains requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for AD8220BRMZ includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Analog Devices is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, headquartered in Norwood, MA.

The AD8220BRMZ belongs to Analog Devices' precision instrumentation amplifier product line, designed specifically for low-power, high-accuracy signal conditioning in portable and industrial measurement systems.

FAQ

What is the maximum gain achievable with the AD8220BRMZ?

The AD8220BRMZ supports a gain range of 1 to 1000, set by a single external resistor across the RG pins using the formula G = 1 + (49.4 kΩ / RG). At G = 1000, the small-signal bandwidth reduces to 14 kHz, and CMRR remains ≥92 dB (B grade). The AD8220BRMZ datasheet specifies performance across this full range under defined load and temperature conditions.

Does the AD8220BRMZ support single-supply operation?

Yes, the AD8220BRMZ operates from a single 4.5 V to 36 V supply. With VREF biased at mid-supply (e.g., 2.5 V on +5 V), its rail-to-rail output delivers full swing from 0.15 V to 4.85 V (RL = 10 kΩ). Input common-mode range extends to 0.1 V below −VS, enabling true single-supply sensor interface without level-shifting circuitry.

What is the input bias current specification for the AD8220BRMZ?

The AD8220BRMZ (B grade) has a maximum input bias current of 10 pA at 25°C and ≤100 nA over the full −40°C to +85°C industrial temperature range. This ultra-low value is enabled by its JFET input stage and makes the AD8220BRMZ suitable for high-impedance sources such as pH electrodes, piezoelectric sensors, and photodiode transimpedance feedback networks.

How does the REF pin function in the AD8220BRMZ?

The REF pin on the AD8220BRMZ provides direct control of the output DC offset: VOUT = G × (V+IN − V−IN) + VREF. It must be driven by a low-impedance source (≤40 kΩ) to avoid gain error. This feature enables seamless interfacing with unipolar ADCs, level-shifting for bipolar-to-unipolar conversion, and cold-junction compensation in thermocouple circuits-all without external op-amps.

Is the AD8220BRMZ pin-compatible with other Analog Devices instrumentation amplifiers?

No, the AD8220BRMZ is not pin-compatible with other Analog Devices instrumentation amplifiers such as the AD620 or AD8421. Its 8-lead MSOP pinout (with dual RG pins and dedicated REF terminal) is unique to the AD8220 family. PCB layout must be designed specifically for the AD8220BRMZ footprint and routing requirements, including proper RG resistor placement and REF decoupling.