Analog Devices Inc. AD22050N

Overview

AD22050N from Analog Devices is a single-supply difference amplifier designed for high-accuracy amplification and low-pass filtering of small differential signals (e.g., 100 mV FS at gain = 40) in the presence of large common-mode voltages up to +24 V with +5 V supply. It integrates a laser-trimmed resistive attenuator, precision preamplifier (A1), and output buffer (A2), delivering default gain ×20, 30 kHz bandwidth, and ±0.5% gain accuracy. Used in automotive current sensing where input common-mode exceeds supply voltage.

For engineers reviewing the AD22050N datasheet, AD22050N pinout, AD22050N application, or AD22050N equivalent, key selection considerations include its –1 V to +24 V input common-mode range with +5 V supply, differential input resistance of 400 kΩ, midscale offset capability via Pin 7, 1–3-pole configurable low-pass filtering, and operation from –40°C to +125°C in plastic DIP package.

Technical Context

The AD22050N implements a two-stage signal path: a precision-balanced resistive attenuator (Pins 1/8) reduces common-mode voltage by ~6× before feeding A1, enabling extended CMR; A1 provides ×10 closed-loop gain with internal 100 kΩ trimmed feedback resistor (R12) enabling passive RC filtering at Pin 3. A2 delivers ×2 gain, yielding overall ×20 default gain with ±0.5% trim tolerance.

Its architecture supports accurate bipolar signal conditioning via midscale offset (Pin 7 → +VS yields VO = +VS/2), RF suppression via integrated input capacitors, and transient protection (±34 V reversed supply, +60 V peak input). The output stage lacks active pull-down, limiting minimum output to ~20 mV above ground unless offset is applied - a design trade-off enabling rail-to-rail unipolar swing while preserving CMR integrity.

Key Specifications

Pinout & Package

AD22050N is housed in an 8-pin plastic DIP (N-8) package with 0.3-inch width and through-hole mounting. Pin spacing is 0.1 inch, compatible with standard PCB layouts and socketing.

Key Features

Applications

Equivalent & Alternatives

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

Compared with INA128UA and AD8210YRZ, AD22050N uniquely combines single-supply operation, programmable filtering, and guaranteed midscale offset in one IC - making it the only choice for cost-sensitive, space-constrained embedded systems requiring both high-CMR differential amplification and bipolar signal support without external components.

Availability

AD22050N is available at Aetrix Electronics and suitable for automotive current sensing, industrial motor control, strain gage interfaces, and pressure transducer signal conditioning requiring stable component supply across extended temperature ranges.

Supply support for AD22050N 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, founded in 1965 and headquartered in Wilmington, MA.

The AD22050N belongs to Analog Devices' precision sensor interface amplifier product line, engineered specifically for ruggedized, single-supply signal conditioning of low-level transducer outputs in harsh environments like automotive engine bays and industrial motor drives.

FAQ

What is the maximum common-mode voltage the AD22050N can handle with a +5 V supply?

The AD22050N supports an input common-mode range of –1 V to +24 V when operated from a +5 V supply. This is achieved via its internal 6× resistive attenuator, enabling accurate amplification of differential signals (e.g., 100 mV shunt voltage) even when referenced to a car battery rail that spikes to +20 V - a key advantage over conventional op amps limited to < +5 V CMR.

Can the AD22050N interface directly with a single-supply 12-bit ADC without external level-shifting?

Yes, the AD22050N can interface directly with a single-supply 12-bit ADC. By connecting Pin 7 (OFS) to +VS, the AD22050N centers its output at +VS/2 (e.g., +2.5 V on +5 V), producing a bipolar-compatible range (e.g., +1.5 V to +3.5 V for ±1 V input). Its ±2% midscale offset accuracy and 0.2 µV/√Hz noise ensure >11.5 ENOB performance without external biasing components.

How does the AD22050N achieve 1-, 2-, or 3-pole low-pass filtering without external op amps?

The AD22050N achieves configurable low-pass filtering using its internal architecture: Pin 3 (A1 output) connects to Pin 4 (A2 input) via a trimmed 100 kΩ resistor. Adding a capacitor from this node to ground creates a 1-pole filter; adding a second capacitor and resistor per Figure 7 forms a 2-pole Sallen-Key structure; adding an RC network at Pin 7 yields a 3-pole response - all without external amplifiers, saving board area and cost.

What is the purpose of Pin 3 (A1) and Pin 8 (A2) on the AD22050N?

Pin 3 (A1) is the output of the preamplifier stage (gain ×10), accessible to insert external RC filtering before the output buffer. Pin 8 (A2) is the input to the output buffer stage (gain ×2); strapping Pin 3 to Pin 8 configures the default ×20 gain path. These pins enable flexible gain adjustment (e.g., lowering gain with resistor to ground on Pin 8) and filtering - features not exposed in standard difference amplifiers.

Does the AD22050N require external components to achieve its specified ±0.5% gain accuracy?

No, the AD22050N achieves ±0.5% overall gain accuracy without external components in its default configuration (Pins 3–4 strapped, Pin 7 → +VS). This is accomplished via laser trimming of internal resistors R12, R6, R7, R8, R9, and R10 during manufacturing. External resistors are optional - used only when altering gain beyond ×20 or implementing custom filtering, which introduces additional tolerance dependencies.