Analog Devices Inc. 1B22AN

Overview

1B22AN from Analog Devices is a programmable, isolated voltage-to-current converter with transformer-based galvanic isolation, ±15 V bipolar input supply, +14 V to +30 V loop supply, 1500 V_RMS CMV isolation, and user-selectable 0 V to +5 V / 0 V to +10 V inputs and 4–20 mA / 0–20 mA outputs. It drives up to 1000 Ω loads in industrial process control transmitters.

For engineers reviewing the 1B22AN datasheet, 1B22AN pinout, 1B22AN application, or 1B22AN equivalent, key selection considerations include its isolated loop power capability, ±0.02% nonlinearity, 90 dB CMR at 60 Hz, 300 nA_p-p output noise, and factory-calibrated input/output range programming without external DACs or op-amps.

Technical Context

The 1B22AN integrates modulator/demodulator circuitry with dual transformers: one for signal isolation (1500 V_RMS) and another for isolated loop power generation. Its internal resistor network enables pin-strappable input ranges and offset configuration via jumpering IN1/IN2 and 4 mA OFFSET/S. NODE.

It features synchronous demodulation synchronized by an external 40 kHz clock (via SYNC pin), supports optional gain/offset trimming with external potentiometers, and delivers regulated loop compliance voltage proportional to VLOOP - enabling operation across 8 V to 20 V load compliance depending on supply.

Key Specifications

Pinout & Package

1B22AN uses a 24-pin DIP package measuring 1.0" × 2.1" × 0.35" (25.4 mm × 53.3 mm × 8.9 mm), compatible with AC1225 mating socket.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar isolated voltage-to-current converter applications.

Compared with ADuM4160BRIZ and XTR115UA, the 1B22AN uniquely integrates transformer-based signal *and* power isolation, factory-calibrated analog ranges, and 240 V_RMS output protection - eliminating external components required by alternatives to achieve full 4–20 mA loop isolation.

Availability

1B22AN is available at Aetrix Electronics and suitable for multichannel process controllers, isolated D/A converter interfaces, and remote pressure transmitter designs requiring stable component supply and long-term industrial lifecycle support.

Supply support for 1B22AN 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, Inc. is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, headquartered in Norwood, MA.

The 1B22AN belongs to Analog Devices' isolated signal conditioning product line, engineered specifically for industrial process automation where galvanic isolation, high CMR, and ruggedized 4–20 mA loop compatibility are mandatory.

FAQ

What input voltage ranges does the 1B22AN support?

The 1B22AN supports factory-calibrated, pin-strappable input ranges of 0 V to +5 V or 0 V to +10 V using its internal resistor network. Jumpering IN1 and IN2 selects the 0–5 V range; using IN1 or IN2 individually enables 0–10 V. An external resistor can further scale input down to 0–1 V. The 1B22AN does not require external amplifiers or attenuators to configure these ranges.

How is output current range selected on the 1B22AN?

Output current range on the 1B22AN is selected via pin strapping: connecting the 4 mA OFFSET pin to the S. NODE configures 4–20 mA output, while tying 4 mA OFFSET to P. COM sets 0–20 mA operation. No external components are needed. The 1B22AN delivers full-scale accuracy and ±0.02% nonlinearity in both modes without recalibration.

Does the 1B22AN provide isolated loop power, and what voltage range is supported?

Yes, the 1B22AN includes an internal isolated dc/dc converter that generates loop supply voltage from the VLOOP pin. It accepts +14 V to +30 V on VLOOP and provides corresponding isolated compliance voltage to drive loads up to 1000 Ω. At VLOOP = +28 V, the 1B22AN achieves ≥20 V load compliance - sufficient for standard 4–20 mA loop operation.

What isolation ratings apply to the 1B22AN, and which standards does it meet?

The 1B22AN provides 1500 V_RMS continuous galvanic isolation between input and output circuits, plus 240 V_RMS normal-mode output protection. It meets IEEE STD 472 (SWC) for common-mode transient immunity. These ratings are verified per Analog Devices' test methodology and apply directly to the 1B22AN device under specified operating conditions.

Can multiple 1B22AN units be synchronized to prevent beat-frequency errors?

Yes, the 1B22AN includes a SYNC pin (Pin 23) that accepts an external 40 kHz square wave with 50% duty cycle. Driving all 1B22AN units in proximity from a common clock eliminates radiated oscillator beat frequencies and ensures stable, jitter-free current outputs. Input impedance at SYNC is 150 kΩ || 180 pF, allowing direct connection to standard logic drivers.