AD238AN

Overview

The AD238AN is a CMOS RS-232 line transceiver designed for EIA-232-E and V.28 communications interfaces. It integrates four drivers and four receivers on a single chip, powered by a single +5 V supply. The device utilizes internal charge pumps to generate the required ±10 V output swings from the single supply voltage. It supports data rates up to 120 kb/s and operates within an industrial temperature range of -40 °C to +85 °C. The component is housed in a 24-pin Ceramic Dual In-Line Package (CDIP) with glass-sealed construction.

Feature Summary

• Integrates four independent drivers and four receivers for full-duplex communication
• Generates internal ±10 V output swings using a single +5 V power supply
• Compatible with standard EIA-232-E and V.28 interface specifications
• Constructed in a hermetically sealed ceramic package for environmental robustness

Applications

• Industrial control systems requiring reliable serial communication
• Computer peripherals and instrumentation interfaces
• Modem and printer connections in harsh environments
• Embedded systems needing isolated or robust RS-232 links

Procurement Notes

Verify the specific suffix 'AN' against official Analog Devices documentation to confirm pinout compatibility and package dimensions. Ensure that the ceramic DIP form factor aligns with the target PCB footprint, as surface-mount alternatives exist within the same family. Confirm RoHS compliance status if required by the end application, noting that older ceramic packages may have different regulatory classifications than modern plastic variants.

Selection Notes

Select this component when high reliability and environmental sealing are prioritized over board space efficiency. The ceramic package offers superior protection against moisture and mechanical stress compared to plastic equivalents. Consider the ADM238 series if a transition from legacy MAXIM or ADI parts is needed, ensuring that the external capacitor requirements match the design constraints. Verify that the 120 kb/s speed meets the system's baud rate requirements.

Part Context

The AD238 belongs to the broader ADM2xx/AD2xx family of 5 V-powered CMOS RS-232 transceivers. This family is characterized by its ability to operate without external dual supplies, simplifying power management in single-supply systems. The AD238 specifically represents the ceramic packaged version, often used in military, aerospace, or high-reliability industrial applications where long-term stability and hermetic sealing are critical requirements.

Replacement Considerations

The ADM238LAN serves as a direct functional equivalent in plastic packaging. When substituting, verify that the change from ceramic to plastic package does not violate environmental or mechanical constraints of the assembly. Ensure that the pinout remains identical to avoid PCB redesign.