1B22AN

Overview

The Analog Devices 1B22AN is a programmable, isolated voltage-to-current converter designed for industrial applications. It provides galvanic isolation between input and output circuits using transformer coupling, achieving 1500 V rms common-mode voltage (CMV) isolation. The device accepts pin-programmable analog voltage inputs of 0 V to +5 V or 0 V to +10 V and delivers corresponding current outputs of 4 to 20 mA or 0 to 20 mA. It features an internal isolated loop supply capable of driving loads up to 1000 Ω with a +28 V supply. Key performance metrics include a nonlinearity of ±0.02% typical (±0.05% max), a low offset temperature coefficient of 300 nA/°C, and a gain temperature coefficient of 50 ppm/°C. The unit operates over an industrial temperature range of –40°C to +85°C.

Feature Summary

• Internal isolated loop supply eliminates the need for external DC-DC converters while providing protection against ground loops and high-voltage transients.
• Pin-strappable configuration allows selection of input voltage ranges and output current modes without external programming components.
• High common-mode rejection ratio ensures signal integrity in environments with significant electrical noise.
• Compact DIP package facilitates high channel density in multichannel process control systems.

Applications

• Isolated interface between digital-to-analog converters and standard 4-20 mA current loops
• Pressure transmitter signal conditioning with strain gauge sensors
• Remote data acquisition systems requiring galvanic isolation
• Analog transmitters and controllers in harsh industrial environments

Procurement Notes

Verify component authenticity through authorized distributors or direct manufacturer channels. Confirm that the specific revision matches design requirements, as specifications are subject to change. Check for RoHS compliance status if environmental regulations apply to the end product. Ensure proper handling procedures are followed due to the component's obsolete status and potential availability constraints in the secondary market.

Selection Notes

Select the 1B22AN when high isolation voltage and precise linear conversion are required. Verify that the required load resistance falls within the compliance limits defined by the available loop supply voltage. Consider synchronization capabilities if multiple units operate in close proximity to prevent oscillator beat frequencies. Ensure the input signal range matches the pin-strapped configuration options available on the device.

Part Context

The 1B22 series represents a family of isolated signal conditioners from Analog Devices. The 1B22AN specifically denotes the commercial/industrial grade variant housed in a 12-pin DIP package. This component belongs to a lineage of precision analog interfaces designed for robust performance in noisy industrial settings. It serves as a bridge between low-level sensor signals and standard industrial communication protocols.

Replacement Considerations

Public confirmed substitute part numbers are not available in the provided documentation. The component status is listed as obsolete. Engineers should evaluate current equivalent isolated voltage-to-current converters from Analog Devices or other manufacturers that meet the specific isolation and accuracy requirements.

FAQ

How is the 4 to 20 mA output mode configured?

To configure the 1B22AN for 4 to 20 mA operation, the 4 mA OFFSET node must be jumpered to the S. NODE (Signal Node).

What is the maximum continuous common-mode voltage the device can withstand?

The 1B22AN supports a continuous common-mode voltage of 1500 V rms between the input and output circuits.

How can oscillator interference be prevented when using multiple units?

Interference can be eliminated by driving the SYNC pins of all units with a 40 kHz clock circuit at a 50% duty cycle.